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  • Application of carbon nanotubes in extraction and chromatographic analysis: A review
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-06-12
    Zeid Abdullah ALOthman, Saikh Mohammad Wabaidur

    Carbon nanotube (CNT), a well-known carbon-based nanomaterial has drawn much attention in many application fields including chemistry in the last few decades. Many researchers and scientists have shown huge interest to improve the extraction methodologies and adopt their applications in combination with chromatography technique. With respect to this, the exceptional applications of CNTs have been introduced as extraction sorbent due to their excellent inborn physical and chemical properties. In particular, CNTs have consistently been used as adsorbents in various techniques including solid-phase micro-extraction, solid-phase extraction, micro dispersive slid phase extraction, magnetic dispersive solid phase extraction, analytes enrichment, sample fractionation and clean-up as well as support for many derivatization reactions. Many research papers have discussed the successful use of CNTs to overcome the limitations of the extraction techniques due to their excellent sorbent capacity. In addition, considering the clear need to make chromatographic technique more successful, the applications of CNTs have been reported in the literatures in details as stationary and pseudo-stationary phases for the separation and extraction of challenging compounds. Because of the higher thermal and chemical stability, CNTs have been anticipated as stationary phase modifier for chromatographic applications to avoid bleeding of the columns and enable the analysis even at very high temperature (1200 °C). In liquid chromatography CNTs have primarily been used in combination with other packing materials (silica) and sometimes incorporated in a porous polymeric monolith. Therefore, the recent utilizations of CNTs as extraction materials and stationary phases have been illustrated in the current review and a table listing the details applications of CNTs in aforementioned field is provided as well. We believe that the review will help researcher to gain vast knowledge about application of carbon nanotubes in the field of separation chemistry.

    更新日期:2018-06-12
  • Plasmonic and fluorescent sensors of metal ions in water based on biogenic gold nanoparticles
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-06
    Luisa E. Silva-De Hoyos, Victor Sánchez-Mendieta, Miguel A. Camacho-López, Jésica Trujillo-Reyes, Alfredo R. Vilchis-Nestor

    Gold nanoparticles (AuNPs) were synthesized using a rapid, single step, and completely green biosynthetic method employing aqueous Citrus paradisi (grapefruit) extract, which was used as both the reducing and capping agent. Au(III) ions were rapidly reduced by the aqueous grapefruit extract, leading to the formation of highly stable and crystalline colloidal AuNPs, confirmed by the surface plasmon resonance (SPR) peak centered at 544 nm in the UV–Vis spectra. Biogenic AuNPs have been evaluated as plasmonic, fluorescent and naked-eye sensors of Pb2+, Ca2+, Hg2+, Zn2+ and Cu2+ ions in aqueous media, with a good performance and selectivity. Of the three methods used for metal ions sensing, fluorescent sensors shows better results, specifically with Ca2+, Cu2+ and Pb2+. Copper was detected by both plasmonic and fluorescent methods.

    更新日期:2018-06-03
  • Direct ICP-OES multielement analysis of infused black and green teas and chemical fractionation of selected essential and non-essential elements prior to evaluation of their bioavailability and classification of teas by pattern recognition
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-06
    Pawel Pohl, Anna Szymczycha-Madeja, Maja Welna

    Operationally defined chemical fractionation of Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr and Zn in infusions of loose leaf and bagged black and green teas was carried out. It was based on tandem-column solid phase extraction using reverse-phase and strong cation-exchange extraction tubes connected in series. Concentrations of elements in resultant infusions as well as column effluents and eluates were determined with the aid of inductively coupled plasma optical emission spectrometry and a newly developed simplified sample preparation procedure. It was established that information on separated chemical fractions, particularly the fraction of residual species of elements, had better discrimination power than information about total concentrations of these elements. Differences in chemical fractionation patterns of elements in infusions of analyzed four types of tea led to simple classification of different black and green teas by principal component analysis and linear discriminant analysis.

    更新日期:2018-06-03
  • Synthesis of N'-(Quinazolin-4-yl)isonicotinohydrazides and their biological screening, docking and ADME studies
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-06
    Kinjal D. Patel, Rajesh H. Vekariya, Neelam P. Prajapati, Dhaval B. Patel, Hitesh D. Patel, Tauhid Shaikh, Dhanji P. Rajani, Smita Rajani, Naumita S. Shah, Devendrasinh Jhala

    A wide range of 4-chloro-3,4-dihydroquinazolines hybrid isoniazid derivatives were synthesised efficiently via reaction of 4-chloro-3,4-dihydroquinazolines with isoniazid in the presence of catalytic amount of N,N-diisopropylethylamine (DIPEA) under refluxing methanol. All the title molecules were characterized by 13C NMR, 1H NMR, Mass and IR spectroscopy. All the compounds were tested for anti-malarial, anti-microbial and anti-tuberculosis activities. They were further tested for the cytotoxic feature. In-silico molecular docking study and ADME properties were also studied for the title molecules.

    更新日期:2018-06-03
  • Use of Taguchi approach for synthesis of calcite particles from calcium carbide slag for CO2 fixation by accelerated mineral carbonation
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-06
    Mahmut Altiner

    This study is focused on the conversion of harmful materials (calcium carbide slag [CCS] and flue gas) into CaCO3 particles through an accelerated mineral carbonation process. The influences of reaction temperature, amount of Na-oleate, solid-to-liquid ratio, and stirring speed on the properties of CaCO3 particles were determined using XRF, XRD, SEM, FTIR, TG, and contact angle measurements. Experiments were designed based on an orthogonal array L9 (34) of the Taguchi approach. The gas mixture of CO2/N2 (16.3% of CO2 cons.) gas was used to represent the flue gas for each experiment. The formation of CaCO3 particles from CCS depending on time was monitored via SEM. Experiments showed that the presence of Na-oleate in the slurry played a curial role in the carbonation process, and the conversion ratio of CO2 into a solid carbonate phase was higher than that in the experiments conducted without Na-oleate. The crystallite size of CaCO3 particles varied between 11.55 and 38.11 nm depending on the production conditions. Each obtained CaCO3 particles were identified as calcite (cubic-like rhombohedral), which is in high demand in many industrial applications.

    更新日期:2018-06-03
  • Room-temperature fabrication of magnetite-boehmite sol-gel composites for heavy metal ions removal
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-07
    Olga E. Shapovalova, Andrey S. Drozdov, Ekaterina A. Brushkova, Maxim I. Morozov, Vladimir V. Vinogradov

    Magnetite-boehmite porous ceramic composites were synthesized from magnetite and boehmite hydrosols in a course of room-temperature sol-gel transition. The proposed synthesis routine allowed producing ceramic matrices with a high degree of structure homology, realizing the full range of composites combining magnetite and boehmite phases at any mass ratio. Depending on the magnetite to boehmite ratio the total surface area of the composites can be varied from 122 to 391 m2/g while the magnetization of the composites can reach up to 88 e.m.u./g. The synthesized composites were examined as adsorbent for Cr(VI) ions, and showed the pseudo-second order sorption kinetics. The characterized adsorption behavior was in best accord with the Langmuir model, showing the maximum adsorption capacities of Cr(VI) ions up to 62.4 mg/g. Owing to their magnetic properties the magnetite-containing composites can be magnetically separated and reused for up to 5 times with only minor drop to the sorption capacity down to 89 % of its initial value. These make the magnetite-boehmite composites prospective for various applications, including wastewater treatment.

    更新日期:2018-06-03
  • Cytotoxicity assay of plant-mediated synthesized iron oxide nanoparticles using Juglans regia green husk extract
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-10
    Zahra Izadiyan, Kamyar Shameli, Mikio Miyake, Hirofumi Hara, Shaza Eva Binti Mohamad, Katayoon Kalantari, Siti Husnaa Mohd Taib, Elisa Rasouli

    Synthesis of iron oxide nanoparticles has attracted increasing interest due to their importance in biomedical and technological applications. To investigate the ability of Juglans regia (J. regia) green husk extract in iron oxide nanoparticles size control, they were synthesized through co-precipitation method with J. regia extract and without it. For both tests, other experimental conditions were same. According to High-resolution transmission electron microscopy, the mean diameter and standard deviation of iron oxide nanoparticles and J. regia/iron oxide nanoparticles synthesized using co-precipitation method were 12.60 ± 2.87 and 5.77 ± 1.66 nm respectively. These results showed that J. regia/iron oxide nanoparticles synthesized using extract have a smaller size than nanoparticles fabricated by co-precipitation method; moreover, green husk extract plays the main role as size control. The obtained results of Powder X-ray diffraction (PXRD), High resolution transmission electron microscopy (HR-TEM), Field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray (EDX) are in good agreement with each other and confirm the high purity of fabricated magnetic nanoparticles using J. regia extract. Vibrating sample magnetometer (VSM) revealed that the J. regia/iron oxide nanoparticles due to their proper magnetic properties have high saturation magnetization and low coercivity. According to FTIR spectrum, the J. regia would be coated on the iron oxide nanoparticles surface in a successful manner. The non-toxic effect of J. regia/iron oxide nanoparticles concentration below 1000 µg/ml was observed in the studies of in vitro cytotoxicity on normal and cancerous cell lines, respectively. The dose-dependent toxicity made it a suitable candidate for various medical applications.

    更新日期:2018-06-03
  • Multi-walled carbon nanotubes modified with iron oxide and silver nanoparticles (MWCNT-Fe3O4/Ag) as a novel adsorbent for determining PAEs in carbonated soft drinks using magnetic SPE-GC/MS method
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-11
    Mojtaba Moazzen, Amin Mousavi Khaneghah, Nabi Shariatifar, Mahsa Ahmadloo, Ismail Eş, Abbas Norouzian Baghani, Saeed Yousefinejad, Mahmood Alimohammadi, Ali Azari, Sina Dobaradaran, Noushin Rastkari, Shahrokh Nazmara, Mahdieh Delikhoon, GholamReza Jahed Khaniki

    The synthesis of compounds with an excellent adsorption capability plays an essential role to remove contaminants such as phthalic acid esters (PAEs) with potential carcinogenic characteristics from different food products. In this context, for the first time, a novel adsorbent (MWCNT-Fe3O4/Ag) was synthesized by using iron (magnetic agent), and silver (catalytic and surface enhancer agent) to further approach in a magnetic SPE-GC/MS method for determining of PAEs in carbonated soft drink samples. The limit of detection (LOD) and limit of quantification (LOQ) values of MSPE-GC/MS were determined in six PAEs as a range of 10.8–22.5 and 36–75 ng/L, respectively. Also, the calibration curves of PAEs were linear (R2 = 0.9981–0.9995) over the concentration level of 10.000 ng/L and the recoveries of the six PAEs were ranging from 96.60% to 109.22% with the RSDs less than 8%. Moreover, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and transmission electron microscopy analyses (TEM) were utilized to characterize the produced MWCNT-Fe3O4/Ag. Based on the findings, the surface of MWCNT is relatively uniform, which became coarser after loading with Fe3O4/Ag particles. Also, EDX spectrum showed the carbon (C), iron (Fe), oxygen (O), Ag and copper (Cu) are the main components of synthesized MWCNTs-Fe3O4/Ag. The successful adhesion of Fe3O4/Ag on the texture of MWCNTs using a co-precipitation method was confirmed by XRD and FT-IR assays. Additionally, excellent crystallinity and clear lattice nanocrystals fringes of prepared MWCNT-Fe3O4/Ag was demonstrated by TEM analysis. Based on the obtained VSM images, the prepared sorbent (MWCNT-Fe3O4/Ag) has the good magnetic performance for magnetic separation and extraction processes. It was concluded that the synthesized MWCNT-Fe3O4/Ag could be used as an efficient adsorbent for determining contaminants such as PAEs in different beverage samples.

    更新日期:2018-06-03
  • Tertiary NiCuZn ferrites for improved humidity sensors: A systematic study
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-11
    Constantin Virlan, Florin Tudorache, Aurel Pui

    Numerous works on ferrites containing three or more divalent cations offer incomplete data thus failing to offer clear correlations between composition and properties. This study describes the magnetic and electrical behaviour of spinel ferrites containing Ni, Cu and Zn. Samples with the general formula Ni0.nCu0.cZn0.zFe2O4, with all metals varying between 0 and 0.5, were obtained by the co-precipitation method. The structure of the samples was investigated by X-ray diffraction and infrared spectroscopy, confirming the formation of pure spinel ferrites. The lattice parameter calculation and EDX analysis confirm the composition of the samples.The magnetic behaviour of the nanoparticles is, in general, superparamagnetic with few samples that present small coercivity, corresponding to larger crystallite size. The measurements indicate the superparamagnetic size limit to be of about 14 nm, which can be observed for samples with low zinc content. The electrical properties of the nanoparticles vary with the composition with dominant indirect effect through microstructural changes. All samples have a similar behaviour in relation to electrical current frequency, with variations of about one order of magnitude resistivity. The relative permittivity indicates several samples that change behaviour, such as nickel rich samples, that significantly decrease relative permittivity at higher frequencies compared to zinc rich samples with smaller variations. All samples present variations in the presence of water vapour but increased sensitivity towards humidity was observed for nickel rich samples characterized by larger crystallite size and density.

    更新日期:2018-06-03
  • An improved method to obtain essential oil, flavonols and proanthocyanidins from fresh Cinnamomum japonicum Sieb. leaves using solvent-free microwave-assisted distillation followed by homogenate extraction
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-11
    Chunchao Zhao, Xinyu Yang, Hao Tian, Lei Yang

    An efficient solvent-free microwave-assisted distillation followed by homogenate extraction method (SFMD-HE) was established to separate the essential oil, non-volatile flavonols and proanthocyanidins from Cinnamomum japonicum Sieb. leaves. In the SFMD-HE technology applied in this work, no excessive water was introduced into the system, which can reduce the loss of flavonols and proanthocyanidins in the subsequent extraction process, avoid the generation of hydrosol and improve essential oil yield. Furthermore, no drying was required, which can reduce the energy consumption. The homogenate process can reduce the production of dust and environmental pollution, meanwhile, avoid the degradation and deterioration of some thermo-sensitive compounds. Through comparison, solvent-free microwave distillation was selected as the optimal method, and the 71% ethanol volume fraction was chosen for homogenate extraction. Based on the yields of essential oil, flavonols and proanthocyanidins, the process parameters (microwave irradiation power and time for essential oil distillation; homogenate time, liquid-solid ratio, and ethanol volume fraction for flavonol and proanthocyanidin extraction) were optimized. Due to the combined effects of these parameters, greater advantages were found for the proposed process compared with traditional methods. Therefore, the proposed technique is a good alternative for distilling essential oil and extracting non-volatile components from edible plants.

    更新日期:2018-06-03
  • Pectin based nanocomposite membranes as green electrolytes for direct methanol fuel cells
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-12
    S. Mohanapriya, G. Rambabu, S.D. Bhat, V. Raj

    Biocomposite materials are highly attractive for research and industrial application due to biodegradability, nontoxicity and sustainablility. Solid electrolyte membrane derived from biodegradable materials broadens scope of using sustainable polymers and is easily disposable at the end of life cycle. In this study, Pectin (PC) is blended with polyvinyl alcohol (PVA) in order to fabricate new class of hybrid nanocomposite followed by addition of sulfonated titanium dioxide (s-TiO2) nanoparticles as inorganic proton conducting material. PVA and PC is in situ cross-linked using dual cross-linker comprising a mixture of sulfosuccinic acid and glutaraldehyde followed by solvent casting. Rheological studies with polymer solutions are conducted to study alignment and disentanglement of polymer chains at molecular level. It is shown that rational design of membrane microstructure with proper arrangement of hydrophobic/hydrophilic domains has been formulated by blending PVA with PC. PC-PVA blends with a flexible polymeric network which is appropriate to disperse rigid s-TiO2 nanoparticles resulting in improved proton conductivity and restricted methanol permeability. With further enriched proton conductivity by the presence of s-TiO2 nanoparticles, fabricated PC-PVA/s-TiO2 hybrid nanocomposite membrane exhibit a peakpower density of 27 mW/cm2 at 70°C in DMFCs.

    更新日期:2018-06-03
  • Polymeric microparticles for modified release of NPK in agricultural applications
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-13
    Júnior Olair Chagas, José Messias Gomes, Isabela Cristina de Matos Cunha, Nathalie Ferreira Silva de Melo, Leonardo Fernandes Fraceto, Gilmare Antônia da Silva, Fabiana Aparecida Lobo

    The aim of this work was to synthesize polymeric microparticles as carriers for nitrogen, phosphorus, and potassium (NPK fertilizer) for agricultural applications, using polyglycerol (PG) to improve the synthesis procedure. Multivariate experimental designs were employed to obtain a satisfactory synthesis. The desirability function identified the best conditions for preparation of the microparticles as being 100.00 mg of poly(ε-caprolactone) (PCL), 825.00 mg of PG, 9.25 mL of chloroform, and 0.9% w/v of polyvinyl alcohol (PVA). This resulted in average encapsulation rates of 94.23% for N, 99.80% for P, and 65.00% for K. The profile of release from the microparticles was according to diffusion following Fick’s Law. These observations confirmed the capacity of the proposed microparticles to sustain a continuous and prolonged release of NPK for the purpose of plant fertilization.

    更新日期:2018-06-03
  • New and feasible method for total phosphorus and sulfur determination in dietary supplements by ion chromatography
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-13
    Marcia Foster Mesko, Marcelo Guerreiro Crizel, Diogo La Rosa Novo, Carla Andrade Hartwig, Filipe Soares Rondan, Cezar Augusto Bizzi

    The microwave-assisted digestion of dietary supplements using diluted nitric acid under oxygen pressure for subsequent indirect determination of phosphorus and sulfur by ion chromatography (IC) was proposed. Different concentrations of nitric acid (from 1 to 14.4 mol L−1) and oxygen pressures (from 5 to 20 bar) were evaluated. Dissolved organic carbon and residual acidity were used to choose the most suitable digestion condition. Using the proposed method, it was possible to digest up to 1350 mg of dietary supplements using only 5 mol L−1 HNO3 under 5 bar of oxygen pressure. Comparing to conventional digestion procedure it was possible to digest up to 60% higher sample mass using HNO3 around 30% more diluted. Recoveries ranging from 96 to 102% were obtained when recovery tests using a standard solution or a mixture with certificate reference material were carried out. The concentration of P and S indirectly determined by IC agreed with the results obtained by conventional microwave-assisted digestion using concentrated HNO3 and subsequent determination by inductively coupled plasma optical emission spectrometry.

    更新日期:2018-06-03
  • Comparative study on the essential oils of Artemisia judaica and A. herba-alba from Saudi Arabia
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-13
    Lamya H. Naser Al-Wahaibi, Adeem Mahmood, Merajuddin Khan, Hamad Z. Alkhathlan

    The volatile chemical constituents derived from two Asteraceae species (Artemisia judaica and A. herba-alba) were analyzed and compared for the first time using gas chromatography techniques (GC–MS, GC–FID, Co-GC, LRI determination, database and literature searches) on two different stationary phase columns (polar and nonpolar). This analysis led to the identification of a total of 110 and 81 components from whole plant (stems, leaves and flowers) oils of A. judaica and A. herba-alba respectively. The major classes of compounds in both plants included oxygenated monoterpenes, sesquiterpenes and hydrocarbons. The prominent components in the oil of A. judaica were β-eudesmol, hexadecanoic acid, spathulenol, eudesma-4 (15),7-dien-1-β-ol, carvacrol and thymol which account for 67.3% of the total essential oils composition (96.7%). While the main oil constituents from A. herba-alba were piperitone, (E)-ethylcinnamate, (Z)-ethylcinnamate, thymol, isophrone which account for 78.0% of the total oil composition (99.6%). Comparison showed similar composition in thymol and spathulenol while in others major constituents, have opposite values. To the best of our knowledge, both plant species (A. judaica and A. herba-alba) from Saudi Arabia were considered for the first time in this study. In addition, the oils of these plants were screened for their bio-activities and were found to possess significant anti-microbial activities.

    更新日期:2018-06-03
  • Enhanced accessibility of active sites in hierarchical ZSM-5 zeolite for removal of pharmaceutically active substances: Adsorption and microcalorimetric study
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-14
    Vladislav Rac, Vesna Rakić, Dušan Stošić, Vladimir Pavlović, Sanja Bosnar, Aline Auroux

    The possibility of removal of pharmaceutically active substances, atenolol, diclofenac sodium and salicylic acid, from water solutions using hierarchical form of zeolite ZSM-5 is investigated in this paper. Mesopore formation in ZSM-5 was achieved using alkaline treatment. Zeolitic samples were characterized by X-ray diffraction, low temperature nitrogen adsorption, solid-state 27Al MAS NMR, point of zero charge determination and microcalorimetry – volumetry of ammonia adsorption. Adsorption isotherms of pharmaceutically active substances were obtained and liquid calorimetric experiments were used to evaluate the strength of interactions. The capacity for salicylic acid adsorption measured for the mesoporous sample did not significantly differ from the results obtained for the parent ZSM-5. However, in the case of atenolol and diclofenac sodium, mesoporous ZSM-5 exhibited increased adsorption capacities. Calorimetric data revealed higher heats of atenolol adsorption on mesoporous ZSM-5, compared to the parent. Based on similar acidity and surface charge determined for the two samples, our results show that geometry and dimensions of both zeolite pores and adsorbing molecules play a crucial role in the studied adsorption processes and that tailoring ZSM-5 porosity by desilication can be used to expand its applicability in depollution processes.

    更新日期:2018-06-03
  • Benzo[7,8]indolizinoquinoline scaffolds based on Mg(ClO4)2-promoted regiospecific imide reduction and π-cyclization of N-acyliminium species. Analogues of the topo-1 poison rosettacin and 22-hydroxyacuminatine alkaloids
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-14
    Abdulkareem Hamid, Abdelaziz Souizi, Ata Martin Lawson, Mohamed Othman, Alina Ghinet, Benoît Rigo, Adam Daïch

    A general five-step synthesis of a short library of benzo[7,8]indolizinoquinolinine analogues of the topoisomerase-1 (topo-1) poison rosettacin and 22-hydroxyacuminatine alkaloids from DMAD and ortho-ketoanilines is reported. This consists on successively, the tandem aza-Michael addition/cyclodehydration, the hydrolysis of the resulting diesters into corresponding o-dicarboxylic acids, and the tandem intermolecular amidation/cyclodehydration into N-substituted imides. The regioselective reduction of one imide carbonyl into corresponding α-hydroxy lactams promoted by a Lewis acid Mg(ClO4)2 was followed ultimately with TFA-promoted π-cationic cyclization via stable N-acyliminiums species as an important key step.

    更新日期:2018-06-03
  • An efficient sample preparation method based on dispersive liquid–liquid microextraction associated with back extraction for trace determination of acidic pharmaceuticals
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-14
    Mahnaz Ghambarian, Fateme Tajabadi, Yadollah Yamini, Mohammad Behbahani, Hamid Reza Sobhi, Ali Esrafili

    Reduction of matrix effect seems to be a great challenge for the development of a practical method in bioanalysis. In this regard, a simple and efficient DLLME procedure along with a back-extraction step (DLLME-BE) was developed for the preconcentration of four common non-steroidal anti-inflammatory drugs (NSAIDs) in various biological fluid samples. Briefly, the analytes of interest were initially transferred into the extraction solvent followed by the back-extraction into an immiscible basic methanol (as an acceptor phase) for further preconcentration and clean-up. The main purpose of the work is reducing the matrix effect and sensitive determination of target molecules in the complex matrices. Following on, the separation and determination of the analytes were carried out using GC–MS (in-port derivatization) and HPLC-DAD instrument. The influential parameters affecting the DLLME-BE method were evaluated in detail and the best extraction conditions were established. Under the optimum conditions, low method detection limits in the range of 0.1–1.0 and 0.1–6.0 µg L−1 were obtained for GC–MS and HPLC-DAD analysis, respectively. Additionally, fair intra-day precisions of 2.7–14.5 and 2.8–7.8% as well as inter-day precisions of 3.9–14.5 and 3.5–8.1% were achieved for the GC–MS and HPLC-DAD analysis, respectively. Finally, the method was successfully applied for the determination of four common NSAIDs in different biological fluid samples.

    更新日期:2018-06-03
  • Pre-column derivatization HPLC method for rapid and sensitive determination of free and total formaldehyde in hair straightening products
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-14
    Mona M. AlShehri, Maha A. AlMeshal

    This paper describes development and validation of rapid and sensitive pre-column derivatization HPLC method to determine free and total formaldehyde content in five hair straightening products purchased from the local market. None of these products was labeled to contain formaldehyde and all of them were labeled with specific formaldehyde releasers. The formaldehyde derivative was separated using a µBondapak™ C18 column with mobile phase consisted of acetonitrile: water (70:30, v/v) and detected at 350 nm. The method was linear over the concentration range of 8–80 ng mL−1 (r = 09997) with detection limit of 0.8 ng mL−1. The formaldehyde derivative was stable for 30 days at room temperature. The results showed that all the samples were formaldehyde positive. The concentrations of free and total formaldehyde were 0.015–3.336 g% and 1.462–3.877 g%, respectively. The method showed high precision as the values of relative standard deviations (RSD) did not exceed 2.20%.

    更新日期:2018-06-03
  • Novel supercapacitor electrodes based semiconductor nanoheterostructure of CdS/rGO/CeO2 as efficient candidates
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-19
    Asma A. Ali, Ahmed Abdel Nazeer, Metwally Madkour, Ali Bumajdad, Fakhreia Al Sagheer

    In this study, we have synthesized metal oxide/metal sulphide based nanoheterostuctures mediated with graphene nanosheets. The synthesized nanoheterostructures were characterized via different techniques such as XRD, XPS, and TEM. The electrochemical characteristics of the investigated nanoheterostucture (CdS/rGO/CeO2) were investigated through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge-discharge. The specific capacitance of the single rGO, binary CdS/CeO2 and ternary CdS/rGO/CeO2 heterostructures were measured. The CdS/rGO/CeO2 nanoheterostucture showed the most excellent cycling stability with high specific capacitance of 407 F g−1 achieved at a charge-discharge rate of 1 A/g. The investigated supercapacitor retained about 96% of the initial energy density after charge-discharge at a 10 A/g for 5000 cycles. The ternary CdS/rGO/CeO2 nanoheterostucture revealed the best specific capacitance as the graphene nanosheets increased interfacial electron transfer. The results revealed that the investigated novel nanoheterostucture is among the best reported ones in the literature.

    更新日期:2018-06-03
  • Flurbiprofen conjugates based on hydroxyethylcellulose: Synthesis, characterization, pharmaceutical and pharmacological applications
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-21
    Khawar Abbas, Muhammad Ajaz Hussain, Syed Nasir Abbas Bukhari, Muhammad Amin, Muhammad Nawaz Tahir, Sheshanath V. Bhosale

    Present study deals with fabrication of macromolecular prodrugs (MPDs) of flurbiprofen (FLB) with hydroxyethylcellulose (HEC). FLB was activated using p-toluenesulfonyl chloride and reacted with pre-dissolved HEC to yield HEC-FLB conjugates 1–3. Resultant prodrugs showed moderate to high degree of substitution (DS: 0.40–1.74) and assembled into nanoparticles of 220–550 nm at water/DMSO interface. Pharmacokinetic studies of HEC-FLB conjugate revealed a tmax of 4.0 h indicating delayed release of FLB while t1/2 of 10.63 h indicated sustained release characteristics of the conjugate in rabbit model. Pharmacological studies revealed that HEC-FLB conjugates had immunomodulatory potential as results showed 34 and 36% inhibition of Interleukin-6 and tumor necrosis factor-α, respectively. A 79% inhibition of paw edema indicated anti-inflammatory properties of the conjugates. Cell viability studies indicated safety of the conjugates to L929 cell lines up to 24 h in the range of 2–10 mM. Moreover, thermal analysis indicated greater stability of MPDs than FLB.

    更新日期:2018-06-03
  • Polyurethane glycolysate from industrial waste recycling to develop low dielectric constant, thermally stable materials suitable for the electronics
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-27
    Arunima Reghunadhan, Janusz Datta, Maciej Jaroszewski, Nandakumar Kalarikkal, Sabu Thomas

    We are utilizing a new method to improve the dielectric properties of a conventional polymer using a recycled polymer product. The polyurethane foams are recycled by glycolysis process and the derived material was applied to improve the dielectric properties of the brittle DGEBA epoxy resin. Two main parameters that determine the applicability of the material as a dielectric (the dielectric constant and dielectric loss), were studied at room temperature for all the blends. The properties like dielectric constant and modulus were found to be very low by the inclusion of the different compositions of recycled polyurethane. 20 phr blend was selected for optimum properties and it shows a lower dissipation factor of 1.5 × 10−2. The blends are advised as good candidates for the use in microelectronics as insulations, encapsulation and or circuit boards. We presented here an easy to process material with all the good properties require for a dielectric material. The thermal and dielectric data showed improvement than the neat polymers. The dielectric data was supported by the low water uptake of 0.5% by 20 phr blend and slightly increased contact angle from 63° to 77°.

    更新日期:2018-06-03
  • A facile and green synthetic approach toward fabrication of Alcea- and Thyme-stabilized TiO2 nanoparticles for photocatalytic applications
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-27
    Negar Arabi, Abbas Kianvash, Abdollah Hajalilou, Ebrahim Abouzari-Lotf, Vahid Abbasi-Chianeh

    A facile and green synthetic approach was considered for the synthesis of stabilized titanium dioxide (TiO2) nanoparticles. Extracts of Alcea and Thyme plants were used to synthesis TiO2 nanoparticles for photocatalytic applications. Evaluation of the structural and phase formation via X-ray diffraction (XRD) indicated the formation of the anatase phase of TiO2 along with the rutile phase. A desired single phase of anatase was obtained upon heating the as-synthesized samples at 500 °C for 3 h. Using the information provided by the XRD analyzer and the Debye Scherer relationship, the average crystallite size was found to be around 6 and 10 nm for the samples synthesized using Alcea and Thyme plants, respectively. To determine the elemental analysis and chemical structure, the energy dispersive X-ray (EDX) analyzer and Fourier Transform Infrared (FTIR) spectroscopy were employed. Field emission scanning electron microscopy (FESEM) indicated batches of ultrafine agglomerated particles for both samples, which their sizes grew by the heating process. The UV–visible analysis of photocatalytic properties confirmed the priority of TiO2 nanoparticles prepared with Thyme extracts.

    更新日期:2018-06-03
  • Flexible FKM/mRGO nanocomposites with excellent thermal, mechanical and electrical properties
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-29
    Grace Moni, Anshida Mayeen, Jiji Abraham, Thomasukutty Jose, Maya M G, Rabindranath Bhowmik, Soney C. George

    Nanocomposites having multifunctional properties with simultaneous improvement in thermal, mechanical and dielectric properties along with improved ferroelectric signature are of considerable interest due to the rapidly growing need in the technological aspect. In the present work, microwave reduced graphene oxide (mRGO)/fluoroelastomer nanocomposites with enhanced dielectric performance and ferroelectric characteristics were developed. mRGO was synthesized from natural graphite via GO and was confirmed by analyzing the chemical changes using X-ray diffraction technique, Fourier transform infrared and Raman spectroscopy studies. The addition of the mRGO improved the mechanical, dielectric and ferroelectric characteristics of the nanocomposites by its better dispersion in the polymer matrix as confirmed by TEM and AFM analysis. The enhanced polymer filler interaction was also confirmed by analyzing the Kraus Plot. Nanocomposite with 0.75 phr of filler loading showed optimum mechanical properties with increased Tg of about −12.25 °C. This is an evidence for the enhancement in properties due to the improved filler-polymer electrostatic interaction. Nanocomposites showed several-fold increase in the dielectric constant value compared to the gum sample. Moreover, the nanocomposites have minimum dielectric loss at 1 MHz frequency. The incorporation of mRGO created a conductive pathway by the microcapacitor effect and the nanocomposites showed enhanced AC conductivity. Ferroelectric studies revealed that the coercive field (Ec) and the remnant polarization (Pr) of the nanocomposites were increased with filler loading that signifies the improvement in ferroelectric signature of the nanocomposites. The samples show excellent dielectric and ferroelectric properties along with better thermal and mechanical stability, and hence, will be promising candidate for ultra-modern storage devices.

    更新日期:2018-06-03
  • Electrochemical detection of dihydronicotinamide adenine dinucleotide using Al2O3-GO nanocomposite modified electrode
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-31
    Moataz M. Mekawy, Rabeay Y.A. Hassan, Pankaj Ramnani, Xuejun Yu, Ashok Mulchandani

    NADH plays a vital role in the electron transfer processes between metabolites in the cellular energetic reactions. Therefore, there is a crucial need to develop analytical techniques for detecting NADH levels with the metabolism of glucose. In the present study, a nanocomposite of alumina (Al2O3) nanoparticles confined graphene oxide (GO) sheet acts as a modifier for carbon paste electrode (CPE) for a sensitive detection of NADH level in a mediator-less detection scheme. Our findings after optimization of experimental conditions reveal that, there is a remarkable enhancement in the direct electron transfer through the Al2O3-GO nanocomposite surface with high electrocatalytic activity towards NADH oxidation. Results show that, there is a linear increase in NADH detection from 30 µM to 330 µM, together with linear regression coefficient of 0.98 and LOD 4.5 µM. These results confirm that, the developed Al2O3-GO based CPE electrode is a promising electrode for real NADH level detection in practical enzymatic applicability.

    更新日期:2018-06-03
  • Investigations of addition of low fractions of nanoclay/latex nanocomposite on mechanical and morphological properties of cementitious materials
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-31
    Mehdi Hatami, Akbar Dehghan, Nader Djafarzadeh

    In this study, we report the synthesis, characterization and performance of organic-inorganic hybrid (OIH) cementitious nanocomposites. OIH was synthesized by the insertion of polymer latex particles in the structure of clay nanoplates. Polymer latex particles were prepared by the polymerization of three different organic monomer comprising styrene monomer (St), 2-ethyl hexyl acrylate (EHA), and methacrylic acid (MAA). Poly(St/EHA/MAA) was prepared by a semi-continuous emulsion polymerization process. The prepared OIH was used to modify the cement paste properties. For the fabrication of latex structure various composition of methacrylic acid as a functional monomer was examined. The effect of the variety of the percentage of MAA on latex composition, and also the OIH to cement ratios were optimized. The optimum conditions were applied to the fabrication of nanoclay based blends. The effects of OIH onto the cement paste properties were evaluated by measuring of the compressive and flexural strength analyses. The obtained results showed that the best composition in cementitious matrix was related to the sample of OIH namely CP565, in which comprises of five percent nanoclay. Also FT-IR, XRD, and SEM analyses were performed to exactly identify the effects of OIH onto the cementitious matrix properties.

    更新日期:2018-06-03
  • Unveiling an unexpected potential of beetroot waste in green synthesis of single crystalline gold nanoplates: A mechanistic study
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-31
    Girish K. Deokar, Arun G. Ingale

    A novel green synthetic route developed toward unveiling a mechanism of formation of single crystalline gold (Au) nanoplates, with a flat surface using an aqueous extract of red beetroot waste (BRW) i.e. peel, at room temperature, the first time. The green method monitored using UV–VIS spectrophotometry, the presence of metallic gold, its structure; orientation and the responsible biomolecules; for reduction validated using EDS, XPS, XRD and FTIR spectroscopies respectively. Based on these significant characterizations, a probable three-step mechanism proposed here for nanoplate synthesis. First, the synthesis of the nanosphere, second its transformation into icosahedrons and ultimately its fragmentation into triangular nanoplates. The green synthetic mechanism for these nanoplates is investigated, validated and evidenced by both HR-TEM and XRD studies. The selected area electron diffraction (SAED) patterns and the assessment of Moire’ fringes confirmed that the nanoplates formed in this manner found single crystalline efficiently oriented in {1 1 1} lattice plane as their basal planes.

    更新日期:2018-06-03
  • Optimization and detailed stability study on coupling of CdMoO4 into BaWO4 for enhanced photodegradation and removal of organic contaminant
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-30
    Mohammad Eghbali-Arani, Saeid Pourmasoud, Farhad Ahmadi, Mehdi Rahimi-Nasrabadi, Vahid Ameri, Ali Sobhani-Nasab

    BaWO4 nanoparticles BaWO4/CdMoO4 nanocomposites were synthesized by eco-friendly method at low temperature. The effects of various capping agents such as glucose, fructose, lactose, and starch on the morphology and particle size of BaWO4/CdMoO4 nanocomposites were investigated. The nanocluster was obtained with glucose and Ba2+ to capping agent molar ratio of (1:2). BaWO4/CdMoO4 nanocomposites were analyzed through techniques including, XRD, FT-IR, VSM, TEM, PL, FESEM, UV-Vis, and EDX. According to the BET results, in the presence of glucose as the capping agent, surface area increased from 13.781 m2/g to 122.22 m2/g. Furthermore, adding CdMoO4 nanoparticles to BaWO4 causes optical properties and photocatalytic activity of BaWO4 to improve. Moreover, the effects of several factors such as BaWO4/CdMoO4 nanocomposites concentration and its particle size and difference dyes on the photocatalytic performance of BaWO4/CdMoO4 nanocomposites were studied under visible light.

    更新日期:2018-05-31
  • Establishment of Analytical Method for Quantification of Anti-inflammatory Agents Co-nanoencapsulated and its Application to Physicochemical Development and Characterization of Lipid-Core Nanocapsules
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-31
    Kelly Ayumi Nakama, Renata Bem dos Santos, Carlos Eduardo da Rosa Silva, Jessica Cristina Izoton, Anne Suely Pinto Savall, Maria Eduarda Ziani Gutirrez, Silvane Souza Roman, Cristiane Luchese, Simone Pinton, Sandra Elisa Haas
    更新日期:2018-05-31
  • Green Synthesis of Platinum Nanoparticles Using Saudi’s Dates Extract and their Usage on The Cancer Cell Treatment
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-29
    Najlaa S. Al-Radadi

    Green synthesis of the Platinum nanoparticle of dates is carried out for examining their effect on various cancer cells. The extract solution of Dates (biodegradable surfactant) is used for this purpose. The bio-degradable plant-based surfactant, used in the study, occurs naturally, and no other reducing, or capping agent is used for cancer cell treatment. The aqueous extract solution of popular dates Ajwa and Barni acts as a stabilizing and reducing agent during the production of PtNPs at ambient condition because of simplicity, long-time stability, and cost-effectiveness. In order to achieve the best size and shape of nanoparticles, different ratio of extract and metal salt were mixed and developed. Additionally, nanoparticles of varying size were furnished by altering the pH of the reaction. Spectroscopic techniques like FTIR, X-ray Diffraction (XRD), EDX, thermos-gravimetric analysis (TGA), UV-vis, and transmission electron microscopy (TEM) were applied to identify PtNPs. In this study, electrochemical HPCL and high-performance liquid chromatography (HPCL) are combined for better understanding and effectiveness. The metabolites such as amino acid, sugar, organic acid, flavonoids, phenol, and minerals, in the Dates produced in Al-Madinah Al-Munawarah, have been analyzed with the help of the techniques employed in the study. PtNPs' anticancer activities were evaluated for different cancer cells including the colon carcinoma cells (HCT-116), breast cells (MCF-7), and hepatocellular carcinoma (HePG-2). Commonly used effective anticancer agent, Doxorubicin HCl, is used in the current study related to anticancer activitiy. To discover the antibacterial effect, antibacterial agents Ampicillin and Gentamicin are used. Lastly, the Gram-negative bacteria: Escherichia coli (RCMB 010052) and Gram-Positive Bacteria: Bacillus subtilis (RCMB 010067) were used to determine the antibacterial application of PtNPs.

    更新日期:2018-05-29
  • Fabrication and Characterization of Supported Dual Acidic Ionic Liquids for Polymer Electrolyte Membrane Fuel Cell Applications
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-29
    Masoumeh Zakeri, Ebrahim Abouzari-Lotf, Mohamed Mahmoud Nasef, Arshad Ahmad, Mikio Miyake, Ting Teo Ming, Paveswari Sithambaranathan

    In this study, we proposed an innovative and versatile method for preparation of highly stable and conductive supported ionic liquid (IL) membranes for proton exchange fuel cell applications. Novel covalently supported dual acidic IL membranes were prepared by radiation induced grafting of 4-vinyl pyridine (4-VP) onto poly(ethylene-co-tetrafluoroethylene) (ETFE) film followed by post-functionalization via sequential treatments with 1,4-butane sultone and sulfuric acid to introduce pyridinium alkyl sulfonate/hydrogen sulfate moieties. The advantage of our approach lies in grafting polymers with highly reactive functional groups suitable for efficient post-sulfonation. The membranes displayed better swelling and mechanical properties compared to Nafion 112 despite having more than 3 times higher ion exchange capacity (IEC). The proton conductivity reached superior values to Nafion above 80 °C. Particularly, the membrane with ion exchange capacity of 3.41 displayed a proton conductivity of 259 mScm−1 at 95 °C. This desired conductivity value is attributed to the high IEC of the membranes as well as dissociation of the hydrophobic ETFE polymer and hydrophilic pyridinium alkyl sulfonate groups. Such appealing properties make the supported IL membranes promising for proton exchange membrane fuel cells (PEMFC).

    更新日期:2018-05-29
  • Construction of High Efficient g-C3N4 Nanosheets combined with Bi2MoO6-Ag Photocatalysts for Visible-Light-Driven Photocatalytic Activity and inactivation’s of Bacteria’s
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-29
    Shanmugam Vignesh, Muppudathi Anna Lakshmi, J. Sridhar, Jeyaperumal Kalyana Sundar

    Novel g-C3N4-Bi2MoO6-Ag nanocomposite with their g-C3N4 nanosheets was synthesized by a facile hydrothermal method. The superior photocatalytic performance of gC3N4-Bi2MoO6-Ag nanocomposite was owing to the interface of Bi2MoO6/Ag nanomaterials whereas reduced the bandgap which enables high separation efficiency, suppressed recombination rate of charge carriers and their high specific surface area (97.4 cm3 g−1). For the MB dye degradation efficiency accomplishes 99.6% within 80 min under the visible light. Significantly, the ideal photocatalytic activity of gC3N4-Bi2MoO6-Ag composite has 3.63 times faster than pristine g-C3N4. Based on the trapping test, the superoxide radical O2•- and hydroxyl radical (OH.) plays a vital role in dye degradation in chief g-C3N4-Bi2MoO6-Ag nanocomposite under the visible light exposure. Novel gC3N4-Bi2MoO6-Ag catalyst has been exhibited superior electrochemical performance, which is smaller charge transfer resistance (impedance), and the prime photocurrent response has confirmed that more charge carrier abilities. The physicochemical assemblies and high degradation efficiencies were preserved after five successive cycles, whereas signifying that the sample was displayed good stability. Based on the consistent energy band positions, the probable mechanism for heightening photocatalytic activity was proposed. This study delivers a visible light driven novel g-C3N4-Bi2MoO6-Ag photocatalyst is a capable aspirant material and applicable for environmental remediation. Also, the antibacterial activity is well exposed towards disinfection of the bacterial strain, including pathogens which are S. aureus (G+) and E. coli (G-) bacteria’s.

    更新日期:2018-05-29
  • Synthesis of 2D Boron Nitride doped Polyaniline Hybrid Nanocomposites for Photocatalytic degradation of Carcinogenic Dyes from Aqueous Solution
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-19
    Syed Shahabuddin, Rashmin Khanam, Mohammad Khalid, Norazilawati Muhamad Sarih, Juan Joon Ching, Sharifah Mohamad, R. Saidur
    更新日期:2018-05-19
  • Fluorinated phosphonate analogues of phenylalanine: synthesis, X-ray and DFT studies
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-19
    Joanna Kwiczak-Yiğitbaşı, Jean-Luc Pirat, David Virieux, Jean-Noël Volle, Agnieszka Janiak, Marcin Hoffmann, Donata Pluskota-Karwatka
    更新日期:2018-05-19
  • Insight on the Structural Aspect of ENR-50/TiO2 Hybrid in KOH/C3H8O Medium Revealed by NMR Spectroscopy
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-18
    Omar S. Dahham, Rosniza Hamzah, Mohamad Abu Bakar, Nik Noriman Zulkepli, Abdulkader M. Alakrach, Sam Sung Ting, Mohd Firdaus Omar, Tijjani Adam, Awad A. Al-rashdi

    The ring-opening reactions (ROR) of epoxide groups in epoxidized natural rubber/titania (ENR-50/TiO2) hybrid in potassium hydroxide/isopropanol medium were examined using NMR spectroscopy and supported by the FTIR technique. The thermal behaviour of the hybrid was also studied using TG/DTG and DSC analyses. The 1H NMR results suggested that 16.82% of ROR occurred in the hybrid, while the 13C NMR results exhibited five new peaks at δ 19.5, 71.0, 73.7, 91.7 and 94.4 ppm in the hybrid. 2D NMR, such as HMQC, HMBC and COSY techniques, further scrutinized these assignments. The FTIR spectrum exhibited Ti-O-C characteristics via the peak at 1028 cm-1. The TG/DTG results showed four steps of thermal degradation at 44-148, 219-309, 331-489 and 629-810 °C due to the existence of Ti moieties along with a polymer chain mixture (intact and ring-opened epoxide groups) of ENR-50, which in turn led to an increase in the Tg value of the hybrid to 27 °C compared to that of purified ENR-50 at -17.72 °C.

    更新日期:2018-05-18
  • Selective conversion of stearic acid into high-added value octadecanedioic acid using air and transition metal acetate bromide catalyst: Kinetics, pathway and process optimization
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-15
    Nazmun Sultana, Chandan Guria, Vinod K. Saxena

    Liquid phase selective homogeneous catalytic oxidation of stearic acid (SA) was carried out to obtain industrially important carbon neutral high-added value octadecanedioic acid (ODDA). The oxidation was carried using air, cobalt(II)-acetate, manganese(II)-acetate and HBr catalyst in acetic acid (AcOH) solvent at an elevated temperature and pressure. SA oxidation products were analyzed by gas chromatography-mass spectrometry (GC-MS), gas chromatography (GC) and CO2 analyzer, and SA was oxidized selectively to ODDA without producing CO2 and intermediates like alcohols, aldehydes and ketones. The effect of SA loading (5-20%), pressure (2.8-5.8 barg) and temperature (353-383K) on ODDA yield was studied by varying one variable at a time. Central composite design assisted response surface methodology was employed to find (i) the optimal design of experiments involving several combination of cobalt(II)-acetate (Co: 0-700 ppm), manganese(II)-acetate (Mn: 0-700 ppm) and HBr (Br–: 0-1144 ppm) and (ii) the most influencing variable and interaction among the variables. The synergistic effect of cobalt(II)-acetate in presence of HBr was observed and suggested that SA oxidation proceeds via bromine-bromide cycle. The elevated temperature and pressure along with reduced SA loading enhanced the yield of ODDA. The maximum ODDA yield was found to be 90.5% and corresponding optimum cobalt (II), manganese (II) and bromide concentration were 600.4, 452.2 and 1016.6 ppm, respectively, at fixed SA:AcOH-10:90, pressure-2.8 barg and temperature-383K. Finally, SA oxidation kinetic analysis was determined based on the pseudo-first order homogeneous catalysis and found to be kinetically controlled with an average activation energy 34.55 kJ mol-1. The proposed kinetic model fitted well with the time-variant experimental SA and ODDA concentration under varying operating condition with percent average absolute deviation less than 5.0%.

    更新日期:2018-05-15
  • Preparation and characterization of inexpensive kaolin hollow fibre membrane (KHFM) prepared using phase inversion/sintering technique for the efficient separation of real oily wastewater
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-15
    Siti Khadijah Hubadillah, Mohd Hafiz Dzarfan Othman, Mukhlis A. Rahman, A.F. Ismail, Juhana Jaafar
    更新日期:2018-05-15
  • Effects of a dianion compound as a surface modifier on the back reaction of photogenerated electrons in TiO2-based solar cells
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-07
    Ji Young Kim, Ki Hong Kim, Dae-Hwan Kim, Yoon Soo Han

    The TiO2 films were modified with a dianion compound, 1,2-ethanedisulfonic acid disodium salt (ESD), to give a negative charge (ethane sulfonate anion) on the TiO2 surface, i.e., TiO2-O-SO2-CH2-CH2-SO3-), and effects of repulsion between the negative charge and ions (I3−) of the electrolyte on the performance of dye-sensitized solar cells (DSSCs) were investigated. The reference device without any modification showed a power conversion efficiency (PCE) of 9.89%, whereas for the device with ESD(20)-TiO2/FTO, which was prepared by soaking bare TiO2/FTO in an ESD solution for 20 min, the PCE was increased to 10.97%, due to an increase in both short-circuit current (Jsc) and open-circuit voltage(Voc). It was verified from the measurements of electrochemical impedance, open-circuit voltage decay and dark current that the enhancement in the Jsc and Voc values was attributed to the reduced back reaction between photoinjected electrons and I3− ions, resulting from the presence of the ethane sulfonate anions on the TiO2 surface.

    更新日期:2018-05-08
  • Influence of the surfactant degree of oligomerization on the formation of cyclodextrin:surfactant inclusion complexes
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-05
    Victoria Isabel Martín, Pilar López-Cornejo, Manuel López-López, Daniel Blanco-Arévalo, Antonio José Moreno-Vargas, Manuel Angulo, André Laschewsky, María Luisa Moyá

    Supramolecular complexation is an attractive strategy to modulate the performance of surfactants, e.g., by host-guest interactions. Here, we investigate the interaction of single-chained, di-, tri-, and tetrameric cationic surfactants with cyclodextrins by conductivity and 1H NMR measurements, exploring the effect of increasing the number of the surfactant hydrophobic tails on the stability of cyclodextrin:surfactant inclusion complexes. The stoichiometry and the binding equilibrium constants of the different inclusion complexes were elucidated. Under the working conditions, the number of hydrophobic chains was found not to affect stoichiometry and 1:1 inclusion complexes were formed for all the surfactants investigated. The stability of the host-guest complexes decreases from single-chained to dimeric (“gemini”) surfactants, the binding following a non-cooperative mechanism. This result may be rationalized by taking into account steric constraints and electrostatic effects as well as the need to overcome the hydrophobic interactions between the chains of the same surfactant molecule. However, a further increase in the number of hydrophobic tails, from two to three to four, results in an increase in the equilibrium binding constant, K1. In this case, an increment in the number of chains capable of interaction with the cyclodextrin molecules seems to be the main factor responsible for the increase in K1. ROESY spectra show the coexistence of different types of 1:1 host-guest complexes for tri- and tetrameric surfactants.

    更新日期:2018-05-05
  • Effect of functionalization of iron oxide nanoparticles on the physical properties of poly (aniline-co-pyrrole) based nanocomposites: Experimental and theoretical studies
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-05-04
    Ehsan Nazarzadeh Zare, Tahereh Abdollahi, Ahmad Motahari

    Poly(aniline-co-pyrrole)@functionalized Fe3O4 (PACP@f-Fe3O4) nanocomposites were prepared by a two-step method. In the first step, the Fe3O4-OH and Fe3O4-NH2 nanoparticles were synthesized by the solvothermal and co-precipitation techniques, respectively. In the second step, the PACP@f-Fe3O4 nanocomposites were synthesized by an in-situ microemulsion polymerization technique. The synthesized materials were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Based on the SEM, the iron oxide changed the morphology of the PACP copolymer from being completely nanospheres. The TGA showed the higher thermal stability of the PACP@Fe3O4-OH nanocomposite in comparison to the PACP@Fe3O4-NH2, and the density functional theory (DFT) successfully confirmed this fact by calculating the binding energies between the PACP copolymer and functionalized nanoparticles. Also, the HOMO−LUMO energy gap (EgEg) values were determined by the DFT to investigate the electrical conductivities, which are in accord with the experimental electrical conductivities in the order PACP@Fe3O4-OH> PACP@Fe3O4-NH2> PACP.

    更新日期:2018-05-04
  • Green Biosynthesis of Superparamagnetic Magnetite Fe3O4 Nanoparticles and Biomedical Applications in Targeted Anticancer Drug Delivery System: A review
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-26
    Yen Pin Yew, Kamyar Shameli, Mikio Miyake, Nurul Bahiyah Bt Ahmad Khairudin, Shaza Eva Bt Mohamad, Takeru Naiki, Kar Xin Lee

    This review discussed about the green biosynthesis of magnetite nanoparticles (Fe3O4-NPs) and the biomedical applications, which mainly focus on the targeted anticancer drug delivery. Fe3O4-NPs have been studied and proved that Fe3O4-NPs can be used in various fields of application, due to “superparamagnetic” property that Fe3O4-NPs possessed. In targeted drug delivery system, drug loaded Fe3O4-NPs can accumulate at the tumor site by the aid of external magnetic field. This can increase the effectiveness of drug release to the tumor site and vanquish cancer cells without harming healthy cells. In order to apply Fe3O4-NPs in human body, Fe3O4-NPs have to be biocompatible and biodegradable to minimize the toxicity. So, green biosynthesis plays a crucial role as the biosynthesized Fe3O4-NPs is safe to be consumed by human because the materials used are from biological routes, such as plant extract and natural polymer. However, biosynthesis using plant extract is the most popular among them all as plant extract can act as both reducing and stabilizing agents in the synthesizing process of nanoparticles. This approach is not merely simple, yet economic and less waste production, which is environmental friendly. Several biomedical applications of Fe3O4-NPs are included in this review, but anticancer drug delivery study is discussed in detail. The criteria for Fe3O4-NPs to be used as drug delivery vehicle are discussed so as to study the optimum condition of Fe3O4-NPs in drug delivery application. Many researches showed the promising results of Fe3O4-NPs in treating cancer cells via in vitro study. Hence, this review is significant which summarize the vital points of Fe3O4-NPs in targeted anticancer drug delivery system. Conclusions have been made according to the literature reviewed and some points of view were proposed for future study.

    更新日期:2018-04-27
  • Supramolecular Drug Inclusion Complex of Capecitabine with Cucurbit[7]uril and Inverted Cucurbit[7]uril
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-25
    Hai-Yan Wang, Yang Zhou, Ji-Hong Lu, Qing-Yun Liu, Gui-Ying Chen, Zhu Tao, Xin Xiao

    The interaction of capecitabine (CAP) with cucurbit[7]uril (Q[7]) and inverted cucurbit[7]uril (iQ[7]) was investigated using nuclear magnetic resonance, fluorescence spectroscopy, MALDI-TOF mass spectrometry and isothermal titration calorimetry. The obtained results revealed that the alkyl chain of CAP is located inside the cavities of Q[7] or iQ[7], whereas the other section of CAP remains outside the portal. Our results suggest that both Q[7] and iQ[7] could be promising candidates for excipients used in medicinal and pharmaceutical research fields.

    更新日期:2018-04-25
  • Low-loading of oxidized platinum nanoparticles into mesoporous titanium dioxide for effective and durable hydrogen evolution in acidic media
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-25
    Mabrook S. Amer, Mohamed A. Ghanem, Abdullah M. Al-Mayouf, Prabhakarn Arunachalam, Nezar H. Khdary

    Low-loading of oxidized platinum nanoparticles (0.1 – 0.5 wt.%) was incorporated into mesoporous titanium dioxide support (Ptx/meso-TiO2) via evaporation self-assembly (ESA) approach followed by a two-step calcination processes. The physicochemical characterizations showed that the oxidized Ptx/meso-TiO2 catalysts exhibit high surface area around 200 m2/g and Pt nanoparticles having an average size of 3.0 nm are uniformly incorporated into the mesoporous TiO2 matrix with the existence of Pt(II) and Pt(IV) oxidation states. The Ptx/meso-TiO2 electrocatalysts showed an enhanced electrocatalytic activity with hydrogen evolution onset potential at −10 mV vs. RHE, Tafel slope of −110 mV/dec, small charge transfer resistance, and mass activity that reaches up to 25.7 A/mgPt at −300 mV vs. RHE. The hydrogen evolution mass activity of Ptx/meso-TiO2 electrocatalysts is significantly more efficient than the commercial Pt/C catalysts and Pt nanoparticles supported on nanostructured carbon substrates. Moreover, the Ptx/meso-TiO2 electrocatalysts exhibit excellent durability for a 24-hour electrolysis in acid solution with a further current activation during the prolonged electrolysis. The enhanced mass activity and durability are attributed to the substrate mesoporosity, uniform distribution and strong bonding between the oxidized Pt nanoparticles and the TiO2 substrate. These results demonstrate the promise of the mesoporous TiO2 substrate modified with low loading of platinum nanoparticles for energy conversion technologies.

    更新日期:2018-04-25
  • Integration of Virtual Screening and Computational Simulation Identifies Photodynamic Therapeutics against Human Protoporphyrinogen Oxidase IX (hPPO)
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-25
    Amir Zeb, Chanin Park, Minky Son, Ayoung Baek, Yeongrae Cho, Donghwan Kim, Shailima Rampogu, Gihwan Lee, Youn-Sig Kwak, Seok Ju Park, Keun Woo Lee

    Photodynamic therapy (PDT) is a rapidly evolving area of cancer management against solid tumors. PDT is either administrated by injecting photosensitizer (porphyrins) or by accumulation of intracellular protoporphyrin IX via the inhibition of human Protoporphyrinogen Oxidase IX (hPPO). In this study, novel inhibitors of hPPO have been investigated by integrating virtual screening, molecular docking, and molecular dynamics (MD) simulation. A ligand-based pharmacophore was generated from a training set of 22 inhibitors of hPPO. The selected pharmacophore had four chemical features including three hydrogen bond acceptors and one hydrophobic. The pharmacophore was characterized by highest correlation coefficient of 0.97, cost difference of 53.20, and lowest root mean square deviation of 0.73. The resultant pharmacophore was validated by Fischer’s Randomization and Test Set Validation methods. The validated pharmacophore was used as a 3D query to screen chemical databases including NCI, Asinex, Chembridge, and Maybridge. The screening of chemical databases and the subsequent application of Lipinski’s Rule of Five, and ADMET Assessment Test, retrieved 1176 drug-like compounds. The drug-like compounds were subjected to molecular docking studies in the active site of hPPO to eliminate false positive hits and to elucidate their true binding orientation. Top three candidate molecules with high docking scores and hydrogen bond interactions with catalytic active residues were selected as best best candidate molecules against hPPO inhibitors. The binding stability of selected candidate molecules was evaluated by MD simulation. The MD simulation of hits portrayed strong hydrogen bonds and key hydrophobic interactions with catalytic active residues of hPPO including R59, R97, G159, G332 and flavin moiety of FAD (coenzyme of hPPO). Our study predicts three hit compounds against hPPO, which could possibly accumulate high concentration of protoporphyrinogen-IX, and thereby acting as an intracellular photosensitizer against tumor cells through photodynamic therapy.

    更新日期:2018-04-25
  • Impact of annealing on the structural and optical properties of ZnO nanoparticles and tracing the formation of clusters via DFT calculation
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-22
    Rezq Naji Aljawfi, Moh Jane Alam, F. Rahman, Shabbir Ahmad, Aga Shahee, Shalendra Kumar

    In this report, nanoparticles (NPs) of zinc oxide (ZnO) were synthesized through auto-combustion route and annealed in air at different temperatures: 200, 400, 600 and 800 °C. The single phase nature has been confirmed via X-ray diffraction (XRD) and selected area electron diffraction (SAED) analysis. The average of crystallite sizes increased progressively as the thermal annealing increase and ranging between 13.8 and 39.7 nm. Raman spectra resembled to that of hexagonal ZnO wurtzite structure, the narrowing in E2H (438 cm-1) Raman phonon mode in sequence with further annealing indicates improvement in the crystallinity and reduction in the local atomic defects of oxygen vacancy (Vo2+). The defects create energy deep bands within the band gap region and diminish the UV emission efficiency that has been assessed through photoluminescence (PL) spectroscopic. The donor band of oxygen vacancy (Vo2+) was ∼1 ∼ 1 eV above valence band (VB), whereas the acceptor band of zinc vacancy (VZn2-) was at ∼ ∼ 0.85 eV above the VB. The ZnO NPs that was annealed at lowest temperature of 200 °C exhibited different behavior trend in which the UV-PL band was diminished clearly, blue shifted to lower wave length and appeared as small plateau at the range of 380-270 nm corresponding to high band gap energy (3.8-4.6 eV), which is indicative to low crystal quality and presence of clusters. We used density function theory (DFT) calculation for computing the HOMO-LUMO band gap of supposed clusters ZnnOn (n=2, 3, 5, 10). The high band gap energy of the simulated clusters was agreed with that of ZnO NPs annealed at 200 °C that gives indirect evidence on the formation of clusters.

    更新日期:2018-04-25
  • Acetocatechol functionalized viologen as polyfunctional material that responds to anion, cation and reductant in aqueous and organic solvents ☆
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-17
    Huanhuan Qiao, Yue-Ling Bai, Yongmei Zhao, Feifei Xing, Ming-Xing Li, Shourong Zhu

    Both viologen and catechol have been studied extensively. However, the stability of catechol-Fe(III) without additional oxidant is still not well understood. In this paper, we introduced acetocatechol into viologen to investigate its interactions with anion, cation, and reductant, as well as the stability of its Fe(III) complexes. This acetocatechol functionalized viologen, 1,1'-bis(2-(3,4-dihydroxyphenyl)-2-oxoethyl)- [4,4'-bipyridine]-1,1'-diium chloride (H6V·Cl2) exists in central symmetric ketone cation form in solid state. Viologen cation increased the acidity of the aceto group and deprotonated the enolic proton to form monodeprotonated enolic H5V+ in the presence of anion/base, which had the deepest color in organic solvents. The absorbance maximum of H5V+ increased with the decrease of solvent polarity. It also interacted with B4O72- and MoO42- by forming catechol ester in DMSO solution. The catechol moiety can coordinate to metal ion, especially Fe(III), in both aqueous and DMSO solution. In particular, it coordinated to Fe(III) much more readily in aqueous solution than in DMSO. Green monocatecholato Fe(III) and red-brown bis-catecholato Fe(III) complex also formed in aqueous solution. The monocatecholato Fe(III) complex first-order dimerized in aqueous solution at room temperature but underwent second-order decomposition to Fe(II) complex at 60°C. The biscatecholato Fe(III) complex also transferred to other Fe(III) complexes at first- and second-order at room-temperature and 60 °C respectively. The t1/2 varied from several hours at room-temperature and several minutes at 60 °C at 10-4 M concentration. The interactions of Fe(III) in DMSO is much more complex than that of acetocatecholate without viologen. Fe(III) can also be reduced to free viologen radicals in the presence of sodium Na2S2O4, but not N2H4. In conclusion, this polyfunctional compound responds to anion via aceto and catechol, metal ion via catechol hydroxyl, while reductant via viologen.

    更新日期:2018-04-25
  • Microparticles based on carboxymethyl starch/chitosan polyelectrolyte complex as vehicles for drug delivery systems
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-16
    Rafael F.N. Quadrado, André R. Fajardo

    Microparticles with oval-shape morphology and rough and porous surfaces were prepared by polyelectrolyte complexation of carboxymethyl starch (CMS) and chitosan (Cs). CMS with DS of 0.5, the polyanionic moiety, was synthesized from rice starch with low content of amylose (6%). A preliminary investigation revealed that this kind of starch is more susceptive to esterification than rice starches with higher contents of amylose. The CMS/Cs microparticles showed higher chemical and thermal stability than microparticles prepared by conventional ionotropic crosslinking of Cs with TPP ions. The carboxymethyl groups of CMS are more efficient to neutralize the positive groups of Cs and, also, enhance the entrapment of bovine serum albumin (BSA) in the CMS/Cs matrix as compared to Cs/TPP. In vitro experiments conducted in simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 6.8) with the testing microparticles revealed that the CMS/Cs-BSA microparticles exhibit a highlighted pH-dependent release profile. This desirable property allows controlling the release of BSA more efficiently, which minimizes undesirable issues (e.g. burst effect and non-sustained release). Furthermore, the BSA release from CMS/Cs-BSA microparticles in SIF follows an ideal Zero-order kinetics, which is very attractive for a drug delivery system. Therefore, microparticles based on CMS/Cs polyelectrolyte complex may be promising to control the drug release in specific regions of the gastrointestinal tract.

    更新日期:2018-04-25
  • Porous multifunctional fluoropolymer composite foams prepared via humic acid modified Fe3O4 Nanoparticles stabilized Pickering high internal phase emulsion using cationic fluorosurfactant as co-stabilizer
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-14
    Umair Azhar, Chenxi Huyan, Xiaozheng Wan, Chuanyong Zong, Anhou Xu, Jitao Liu, Jiachen Ma, Shuxiang Zhang, Bing Geng

    Fluoropolymers are very important owing to their excellent application performances, especially in extreme conditions. On the other hand, the preparation of porous fluoropolymers is a difficult task due to unavailability of suitable surfactants as well as tedious synthesis steps. Here we prepared multifunctional porous fluoropolymer composite foams with a simple process of “high internal phase emulsion (HIPE)” by using humic acid modified iron oxide nanoparticles (HA-Fe3O4 NPs) and cationic fluorosurfactant (CFS) (PDMAEMA-b-PHFBA) as co-stabilizer. The inclusion of HA-Fe3O4 NPs in the system made fluoro-HIPE more stable than the emulsion prepared using only CFS or other conventional stabilizers. Morphology of the prepared polyHIPE was easily controlled by altering the concentration of HA-Fe3O4 and/or CFS in the original formulation. Adjustment of the porous structure with open/close cells was performed and the average diameter of the pores tuned between 4.9-23 μm. With the increase in specific surface area by using nanoparticles (NPs) and CFS as co-surfactants, Pickering HIPE monoliths adsorbed double amount of oil compared to foams based solely on HIPE template. Multiple functional groups were bound onto Fe3O4 NPs through HA modification that made the fluoro-monolith capable of adsorbing dye, i.e. methylene blue, from water. A simple centrifugation enabled regeneration of the oil soaked foams and adsorption capacity was not decreased after 10 adsorption/regeneration cycles.

    更新日期:2018-04-25
  • Hierarchical nanocrystalline NiO with coral-like structure derived from nickel galactarate dihydrate: An active mesoporous catalyst for methyl ethyl ketone production
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-14
    Samih A. Halawy, Mohamed A. Mohamed, Adel Abdelkader

    Nanocrystalline NiO with a coral-like structure (38 nm) has been prepared via thermal decomposition of a new precursor, nickel galactarate (NiC6H8O8·2H2O), at 500 °C for 3 h in air. Thermal decomposition of that precursor was studied by TG and DSC techniques. The resultant NiO was physicochemically characterized by XRD, FTIR, SEM, surface area, porosity and CO2-TPD. NiO was found to exhibit a remarkable activity towards the synthesis of MEK from 2-butanol between 200 and 325 °C. In addition, it has shown a great tendency to ease regeneration of the used catalyst after 192 h in stream by simple refreshing method.

    更新日期:2018-04-25
  • Analysis of amphetaminic drug compounds in urine by headspace-dielectric barrier discharge ionization-mass spectrometry
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-11
    Ahsan Habib, Aklima Nargis, Lei Bi, Peng Zhao, Wen Luhong

    Rapid detection of trace level amphetaminic drug compounds in urine is essential to monitor consumption of these abuse drugs by athletes. In this work, the amphetaminic drug compounds were spiked in human urine and analyzed using headspace - dielectric barrier discharge (DBD) ionization-mass spectrometry method. In the headspace method, the urine spiked drug compound was treated with alkali solution, thus the free base amphetaminic molecules were released into the gas phase. The gaseous molecules were then ionized by the DBD ion source placed in front of the mass spectrometer inlet under ambient condition. This method provided comparable sensitivity with the solid-phase microextraction (SPME) in analysis of the amphetaminic compounds where no derivatization or adduct formation was required. The present method also facilitated the sensitivity enhancement with about one order of magnitude in urine compared to standard solution. Carbonate alkali solution showed the highest sensitivity for detection of the drug compounds in urine and the sensitivity was enhanced by using NH3. The limits of detection (LODs) of the various amphetaminic molecules were found to be in the range of 0.10-0.80 ng/mL for standard solutions while those for urine were in the range of 0.04-0.40 ng/mL. The analytical figures of merit of this method were evaluated under ambient condition using suitable internal standard. Results suggested the suitability of this method for analytical routine work in detection of amine-based drugs in doping test and/or in forensic laboratories. A mechanism of enhanced sensitivity by the ammoniated carbonate alkali solution in urine is also discussed.

    更新日期:2018-04-11
  • Ag2O nanoparticles/MnCO3, –MnO2 or –Mn2O3 immobilized on highly reduced graphene oxide composites as an efficient and recyclable oxidation catalyst
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-05
    Mohamed E. Assal, Mohammed Rafi Shaik, Mufsir Kuniyil, Mujeeb Khan, Abdulrahman Al-Warthan, Abdulrahman Ibrahim Alharthi, Ravi Varala, Mohammed Rafiq H. Siddiqui, Syed Farooq Adil

    Silver oxide nanoparticles doped manganese (IV) oxide along with varying percentages of highly reduced graphene oxide (HRG) [Ag2O)1%(–MnO2/(X%)HRG] nanocomposites were fabricated through a simple co-precipitation method followed by calcination at 400 °C. The as-prepared nanocomposite upon calcination at 300 °C and 500 °C temperatures, yields the manganese carbonate (MnCO3) and manganese (III) oxide (Mn2O3) composites i.e. [Ag2O)1%(–MnCO3/(X%)HRG] and [Ag2O)1%(–Mn2O3/(X%)HRG] correspondingly. The structural composition of the prepared nanocomposites has confirmed by several characterization techniques. The nanocomposites have successfully utilized as a catalyst for liquid-phase oxidation of aromatic alcohols in presence of O2 as a green oxidant under alkali-free conditions. In addition, a comparative study has performed to assess the activity of the manganese carbonates and manganese oxides for aerial oxidation of benzyl alcohol into benzaldehyde as a model reaction. Effects of various parameters have thoroughly examined in detail and the Ag2O)1%(–MnO2/(5%)HRG catalyst exhibited the highest activity in the aerial oxidation of benzyl alcohol to benzaldehyde with a 100% conversion and <99% selectivity in a remarkably short reaction time (35 min) than the undoped precursor i.e. Ag2O)1%(–MnO2. The presence of HRG dopant greatly enhanced the catalytic performance of Ag2O–MnO2 nanocatalysts, could be attributed to the presence of carbon vacancies and topological defects as well as oxygen carrying functionalities on the HRG surface and increase in the surface area. The as-prepared catalyst could be efficiently recycled and reused up to five times without discernible drop in its catalytic performance and the product selectivity remained unchanged. The prepared catalyst i.e. Ag2O)1%(–MnO2/(5%)HRG was employed as oxidation catalyst for a series of various substituted benzylic and aliphatic alcohols into their respective aldehydes and yielded complete conversion with excellent product selectivity with no further oxidation to acids.

    更新日期:2018-04-06
  • A novel and convenient oxidation-controlled procedure for the synthesis of oxazolines from TosMIC and aldehydes in water – Anti biofilm activity
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-05
    Rajan Abraham, Prakash Periakaruppan, Karthikeyan Mahendran, Murugappan Ramanathan

    A new convenient procedure for the synthesis of oxazolines from tosylmethyl isocyanide (TosMIC) and aldehydes using imidazole as an efficient catalyst has been reported. The synthesized oxazolines were able to be protected from the oxidation by using just water both as a good solvent and anti oxidant. All the synthesized compounds show good anti biofilm activity against staphylococcus epidermidis.

    更新日期:2018-04-06
  • In vitro and in vivo characterization of mineralized hydroxyapatite/polycaprolactone-graphene oxide based bioactive multifunctional coating on Ti alloy for bone implant applications
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-05
    Nagaraj Murugan, Chandran Murugan, Ashok K. Sundramoorthy

    Hydroxyapatite (HAP) is a form of naturally occurring calcium apatite present in bone and tooth enamel. It is an important biomaterial with diverse biomedical applications such as a surface coating for metallic orthopedic implants. Synthesized pristine HAP has poor mechanical properties, inferior wear resistance and has limits for directly used in bone tissue engineering applications. To address these limitations, we synthesized a suitable orthopedic implant hybrid material (M-HAP/PCL/GO) by using positively charged calcium ions of mineralized HAP (M-HAP) combined with negatively charged graphene oxide-Polycaprolactone (GO-PCL). The successfully synthesized M-HAP/PCL/GO composite was comprehensively characterized by Fourier-transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM). The micro-hardness technique was used to determine the mechanical strength of M-HAP (315±4Hv), M-HAP/GO (370±3Hv) and M-HAP/PCL/GO (455±5Hv). M-HAP/PCL/GO was also tested for its anti-bactericidal impact against Staphylococcus aureus and Escherichia coli. MG63 osteoblast cells cultured on the M-HAP/PCL/GO composite (10 mg/mL) coated sample, displayed outstanding viability after 3 and 5 days of incubation at pH 7.4, which indicated that the composite is suitable material for bone implants and induces the cell proliferation. It was also tested in vivo in Wistar rats and was observably beneficial bone formation within 28 days post-implant operation. These tests proved that the M-HAP/PCL/GO composite can be considered as a prospective candidate for future bone implant applications.

    更新日期:2018-04-06
  • Tailored surface silica nanoparticles for blood-brain barrier penetration: preparation and in vivo investigation
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-05
    B.I. Tamba, V. Streinu, G. Foltea, A.N. Neagu, G. Dodi, M. Zlei, A. Tijani, C. Stefanescu

    Surface modified fluorescent silica nanoparticle derivatives (Ru@SNPs), namely, glucose (Glu) and glucose-poly (ethylene glycol) methyl ether amine (Glu-PEG) coated SNPs were designed and tested for their ability to penetrate the blood-brain barrier (BBB) in mice brain. The new obtained nanoparticles were characterized by field emission scanning electron microscope (FE-SEM), dynamic light scattering (DLS) and Fourier transform infrared (FTIR-ATR) analysis. The BBB penetration and distribution of tailored SNPs in mice brain were examined using confocal laser scanning microscopy (CLSM), flow cytometer (FACS) and transmission electron microscopy (TEM). The promising results obtained by in vivo experiments, point out that silica nanoparticle derivatives are an efficient permeable delivery vehicle that are able to cross the BBB and reach the brain tissues via specific and non-specific mechanisms. These findings will enrich the knowledge to rationally engineer multifunctional nanoparticles, and bring new insights into BBB permeability.

    更新日期:2018-04-06
  • Design, synthesis, molecular properties and in vitro antioxidant and antibacterial potential of novel enantiopure isoxazolidine derivatives
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-04-03
    Siwar Ghannay, Sana Bakari, Moncef Msaddek, Sébastien Vidal, Adel Kadri, Kaïss Aouadi
    更新日期:2018-04-03
  • Development of Cholesterol Biosensor using Au Nanoparticles Decorated f-MWCNT Covered with Polypyrrole Network
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-05
    M. Alagappan, Susan Immanuel, R. Sivasubramanian, A. Kandaswamy

    Cholesterol forms the basic structural components in the biological membrane and is present in several nerve tissues, brain and also serves as a source for the preparation of fatty acids. The determination of cholesterol level is significant in clinical diagnosis for heart problems, thrombosis etc. In this work, we report an electrochemical cholesterol biosensor based on cholesterol oxidase (ChOx) enzyme immobilized on gold nanoparticles – functionalized - multiwalled carbon nanotube (MWCNT) - polypyrrole (PPy) nanocomposite modified electrode. The sensor was fabricated by a two-step approach wherein the Au NPs-f-MWCNT was prepared by wet chemical method followed by electropolymerization of pyrrole. PPy act as a support matrix to hold ChOx and the presence of Au-f-MWCNT increases the electrical conductivity. Cyclic voltammetry (CV) exhibits a decrease in current with increasing cholesterol concentration which arises due to the competing action of Triton X100 surfactant employed for the preparation of cholesterol solution. The AuNPs-f-MWCNT-PPy-ChOx/GCE showed a linear response from 2x10-3 to 8x10-3M in amperometry with a sensitivity and detection limit of 10.12 µA mM-1 cm-2 and 0.1x10-3M respectively. Further, the detection of cholesterol using impedance spectroscopy was also demonstrated. The reproducibility, stability and the validity of the sensor in biological samples were also examined.

    更新日期:2018-03-06
  • Synthesis, self-assembly-behavior and biomolecular recognition properties of thyminyl dipeptides
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-05
    Giovanni N. Roviello, Giorgia Oliviero, Antonella Di Napoli, Nicola Borbone, Gennaro Piccialli
    更新日期:2018-03-06
  • Highly sensitive pressure sensor based on graphene hybrids
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-02
    Mahesh Vaka, Ming Zhe Bian, Nguyen Dang Nam
    更新日期:2018-03-06
  • Study on the properties of FeCrNi/CBN Composite Coating with High Velocity Arc Spraying
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-03-02
    Pan Ding, Jing Song, Xiao-juan Liu, Jing-bo Li, Hui-qin Li, Han-yu Zhao, Jun-yu Duan, You-zhou Jiao

    FeCrNi / CBN cored wire is prepared by use of the pull-type flux cored wire machine (FCWM50 type), FeCrNi / CBN composite coating is made by high velocity arc spraying. The special properties of the composite coating can be improved by adding Cr, Ni and small amounts of rare earth elements to adjust the coating composition. The Tribological properties of FeCrNi/CBN composite coating with high velocity arc spraying is studied. Images and components and cross-section microstructure of coatings are analyzed by means of SEM, and EDS etc. This research indicated that FeCrNi/CBN composite coatings have typical layered structure feature and high bond strength and hardness. Friction of coatings at near room temperature or higher has “Run-up” period. With the increase of temperature, friction coefficient of coatings becomes low and wearing capacity of coatings high. The adding of CBN powder highly improved the wearing capacity of coatings.

    更新日期:2018-03-06
  • The Composition of the Essential Oil and Aqueous Distillate of Origanum vulgare L. Growing in Saudi Arabia and Evaluation of Their Antibacterial Activity.
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-02-27
    Merajuddin Khan, Shams T. Khan, Noor A. Khan, Adeem Mahmood, Abdulaziz A. Al-Kedhairy, Hamad Z. Alkhathlan

    The essential oil and aqueous distillate composition of Origanum vulgare L. were analyzed by GC/MS. Sixty-seven different components were detected in both oils. Sixty-four components were characterized for the oil derived from the aerial parts, whereas thirty-three components in the volatile oil from the aqueous distillates of O. vulgare L., representing 99.8% and 98.5% of the oils, respectively. The main components of the volatile oil from the aerial parts of O. vulgare L. were carvacrol (70.2 ± 1.37%), γ-terpinene (5.6 ± 0.11%), p-cymene (4.5 ± 0.42%), trans-sabinene hydrate (3.8 ± 0.07%), and thymol (2.2 ± 0.12%). In comparison, the main compounds of the volatile oil of the O. vulgare L. aqueous distillates were carvacrol (92.5 ± 0.97%), thymol (2.5 ± 0.09%), and terpinen-4-ol (1.0 ± 0.03%). The antibacterial activity of both oils, along with that of the purified major component, carvacrol, against Gram-positive and Gram-negative strains was assessed. The results revealed that all three samples showed significant antibacterial activity against all tested strains. The IC50 values of the oils derived from the aerial parts and aqueous distillates of O. vulgare L. against the tested strains was in the range of 107−383 µg.mL-1, whereas, the IC50 value of carvacrol was in the range of 53−151 µg.mL-1. The data suggest that carvacrol, a major component of both oils, possesses the highest antibacterial activity of all the constituents and is the main component responsible for the antibacterial activity of Saudi O. vulgare L. oils.

    更新日期:2018-02-27
  • Quantitative Characterization Appreciation of Golden Citrine Golden by The Irraditionof [Feo4]4-
    Arab. J. Chem. (IF 4.553) Pub Date : 2018-02-27
    Guoying, Zhang Xinyan, Li Xiang, Zhang Ye

    With the help of irradiation, [FeO4]4- was excited by one electron from ferric electronic shell, it absorbed the visible light of 550nm, and then made crystal appears golden color which named citrine.27 pieces citrine was confirmed as natural from 32 pieces golden citrine by IR technology, their color parameters were calculated by the colorimeter tests, then how could hue, lightness and chroma contribute to visual color were analyzed too.It reveals that chroma of natural citrines are negatively correlated with hue and lightness, by the control of hue angle on the impact of the chroma, the co-effect of hue and lightness of natural citrine produce moderate influence on chroma. Without the consideration of chroma influence on lightness, lightness and hue angle are high correlated (r=0.924), it is tested the high linear correlation of citrine lightness and hue; while with the consideration of chroma influence on lightness, lightness and hue angle also high correlated (r=0.897), and the high linear correlation of citrine lightness and hue is confirmed. It draws conclusion that in the limit the citrine golden, lightness should be regarded as the first factor when citrine quality evaluation was taken, with the most intuitive representative and most consistent with the expression of perception effect, then the effect of hue and chroma was considered furthermore.

    更新日期:2018-02-27
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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