Facing the alarming problems of depletion of mineral resources and ever-growing pollution by metallic elements, bio-sourced catalysts were prepared from Mn-accumulating plant species from a large-scale program of ecological rehabilitation of mining sites. This new generation of catalysts, “Eco-CaMnOx” catalysts, were obtained directly from a controlled thermal treatment of four species of Grevillea genus, a Mn-rich biomass, and without any further chemical treatment. Eco-CaMnOx catalysts were characterized by MP-AES, XRPD, HRTEM and STEM-EDX. These analyses revealed a natural richness in two unusual and valuable mixed calcium-manganese oxides: Ca2Mn3O8 or CaMnO3. The high efficiency of Eco-CaMnOx catalysts was demonstrated via the epoxidation of various bio-sourced terpenes and lipids, using a mixture H2O2/NaHCO3 as a green co-oxidant. This study demonstrated the high potential of Eco-CaMnOx catalysts as alternatives to oxidative reagents prohibited by REACH regulation but also the efficient synthesis of bio-sourced epoxides, which can be used as monomers for the preparation of biodegradable polymers. Finally, the original composition of Eco-CaMnOx catalysts led to distinctive catalytic behaviors compared to previously studied Eco-Mn and Pyr-Mn, allowing the preparation of sensitive epoxides such as linalool epoxide.

Hydrofluorocarbons (HFCs) are powerful greenhouse gases whose production and consumption must be phased-down in order to reach the reduction goals established by the Kigali Amendment to the Montreal Protocol. However, the share of recycled refrigerant gases remains very low owing to the extremely inefficient separation of refrigerant mixtures by cryogenic distillation. In this sense, the HFCs difluoromethane (R32, GWP = 675) and 1,1,1,2-tetrafluoroethane (R134a, GWP = 1430), together with the hydrofluoroolefin (HFO) 2,3,3,3-tetrafluoropropene (R1234yf, GWP = 4), are among the most common constituents of HFC/HFO refrigerant mixtures currently employed in the refrigeration and air conditioning sector. Therefore, the feasibility of using membrane technology for the selective separation of these compounds is assessed in this work for the first time. A comprehensive study of their gas permeation through several poly(ether-block-amide) (PEBA) membranes that differ on the content and type of backbone segments is performed. Results show that PEBA membranes exhibit superior permeability of R32 (up to 305 barrer) and R134a (up to 230 barrer) coupled with reasonably high selectivity for the gas pairs R32/R1234yf (up to 10) and R134a/R1234yf (up to 8). Moreover, for the blends R32/R1234yf and R32/R134a, the membrane separation performance is not significantly affected under the mixed-gas conditions tested. Thus, results evidence that consideration should be given to membrane technology for the cost-efficient separation of HFCs/HFOs mixtures in order to boost the recycling of these compounds.

This paper presents a systematic approach for the synthesis, selection, design, and optimization of methanol plants. A metaheuristic optimization approach is proposed to reconcile the economic and environmental objectives of the process while incorporating simulation tools for the reliable modeling of the generated alternatives. In addition to shale/natural gas as the primary feedstock, CO2 utilization is considered. Nine different configurations were synthesized, analyzed, and optimized. The optimization variables included the structural configurations as well as design and operating variables such as flowrates, temperatures, and pressures. The model is a multi-objective problem involving economic and environmental objectives. The economic objective function consists of maximizing the net profit. The environmental objective function is aimed at minimizing the total annual CO2 emissions. To perform the optimization of this problem, process data were obtained from the chemical process simulation software ASPEN HYSYS®. The used stochastic optimization algorithm was an Improved Multi-Objective Differential Evolution. A client-server interface based on Component Object Module technology using Excel-Visual Basic for Applications scripts was developed to call the ASPEN HYSYS® simulator repetitively for various sets of input variables. The results offer attractive options for both the economic and the environmental objectives.

Our study proposed an efficient and environment-friendly strategy to realize the locally controllable surface foaming on polymers via near-infrared pulsed laser. This laser foaming was induced by the multi-layer graphene (MLG), and only 0.05 wt.% MLG gave the polymer an excellent foaming performance with good smoothness and a foaming height of 0.41 mm. Benefited from programming and automatically controlling of the laser system, foamed patterns of arbitrary shapes with 3D appearance could be accurately written on the polymer surface. SEM confirmed that the uniform cells produced by laser foaming were mainly ellipsoidal with closed-cell structures (D=31.5 μm); moreover, the surface foam had three layers with a total thickness of 633.7 μm. XPS revealed the surface carbonization of the foam during laser foaming. Both ATR-FTIR and XPS confirmed the weak oxidation of the PP matrix caused by laser due to the appearance of C−O and C=O groups on foams. Besides, the Raman depth imaging demonstrated the layered carbonization distribution in the foam surface. The micro-Raman spectroscopy confirmed that the amorphous carbon and the sp/sp2 carbon (C≡C/C=C) were two main carbonized products of PP. This study also proposed the mechanism of polymer laser foaming induced by MLG.

Co-processing bio-oils with petroleum derived feeds in the existing multi-trillion dollar refining and distribution infrastructure is an attractive option for introducing renewable energy into the fuels marketplace. Considerable research on co-processing bio-oils and vacuum gas oil (VGO) in fluid catalytic cracking units (FCC) using equilibrium catalysts (E-Cat) demonstrated that biomass derived molecules decreased activity of and increased carbon laydown on E-Cat. In this work, 13C-labeled biomass was co-processed with VGO using either an E-Cat or a proprietary zeolite Johnson Matthey catalyst (CP758), which is optimzed for upgrading biomass vapors in a riser reactor, to evaluate the fate of biogenic carbon in FCC products. The results from both catalysts indicate that biogenic carbon was incorporated into alkenes and aromatic hydrocarbons. While no biogenic carbon was found in linear alkanes, it was observed in cycloalkanes during experiments with E-Cat but not with CP758. All produced CO2 was biogenic as was most of the carbon laydown on the catalysts. Several partially deoxygenated biomass compounds, such as alkyl phenols and benzofurans, unexpectedly contained small amounts of carbon from VGO. Although this study was conducted with labeled biomass and not bio-oil, it provides insights to reaction mechanisms for co-processing bio-oil and VGO in an FCC, which is required to develop catalysts that efficiently convert bio oil components during FCC co-processing. This work also demonstrates that comprehensive catalyst development utilizing both biomass and fossil derived feeds is required to maximize the incorporation of biogenic carbon into transportation fuels.

Effective fractionation and utilization of the three main components (cellulose, hemicellulose, and lignin) in lignocellulosic biomass gives a significant opportunity for commercial operation of a lignocellulosic biorefinery. Here, we proposed a one-pot method for lignocellulosic biomass (poplar) fractionation by acidic water/phenol pretreatment at mild temperature (120 oC). By this approach, three phases were obtained: water phase containing hemicellulose-derived sugars, phenol phase containing lignin, and cellulose enriched solid phase. Up to 90% of original lignin was removed with over 96% original cellulose retained in the solid under the optimized conditions (3.5% acid based on biomass weight, 40% phenol content in water/phenol system, 120 oC and 1 h). Additionally, 77% of original xylan was recovered from the water phase in the form of xylose, while negligible amounts of by-products (e.g. furfural) formed due to the mild conditions. The pretreated substrate was enzymatically hydrolyzed to glucose, whose digestibility was 2-3 times higher than those obtained using ethanol and dioxane. The lignin, together with the phenol solvent without further separation, was used to prepare lignin-based phenolic foam with satisfactory mechanical and thermal insulation properties. The work highlights mild one-pot acid-catalyzed pretreatment strategy to separate three main components of lignocellulose, with enhanced processability, so that value-added products can be made, thus providing an effective route for a lignocellulosic biorefinery.

Phosphogypsum – a by-product of phosphoric acid production – piled near eco-sensitive regions, poses both environmental and health risks. By reacting phosphogypsum with NaOH, Ca(OH)2 is produced, which can be utilized for CO2 sequestration. The cost of NaOH, however, and the low market value of the byproduct, a concentrated Na2SO4 stream, hinder the economic viability of this approach. Here, we propose to increase the cost-efficiency of phosphogypsum processing by converting the Na2SO4 to NaOH and H2SO4 using bipolar membrane electrodialysis (BMED). The result is a cleaner and more circular process, as NaOH can be recycled for dissolving phosphogypsum, while H2SO4 can be reintroduced into the industrial phosphoric-acid production, or used to leach valuable metals out of the phosphogypsum. To assess the feasibility of BMED integration, we used a bench-scale system to probe the trade-off between obtaining high base-product concentration; and obtaining high specific energy consumption. This was done for synthetic Na2SO4 solutions at various concentrations, applied voltages, and types of anion-exchange membranes. Economical analysis based on the results showed that a two-step batch BMED process is able to reduce the chemicals cost by 50%, as compared to purchasing NaOH. Integrating BMED with existing approaches can, therefore, improve the sustainability and cost-efficiency of phosphogypsum valorization.

Glycoside hydrolase family 31 (GH31) enzymes show both highly conserved folds and catalytic residues. Yet different members of GH31 show very different substrate specificities and it’s not obvious how these specificities arise from the protein sequences. The fungal α-xylosidase, AxlA, was originally isolated from a commercial enzyme mixture secreted by Aspergillus niger and was reported to have potential as a catalytic component in biomass deconstruction for biofuel industry. We report here the crystal structure of AxlA in complex with its catalytic product, a hydrolyzed xyloglucan oligosaccharide. Based on our new structure, we provide the structural basis for AxlA’s role in xyloglucan utilization, and more importantly, a new procedure to predict and differentiate C5 vs. C6 sugar specific activities based on protein sequences of the functionally diverse GH31 family enzymes.

Biomimetic hydrogels offer a new platform for hierarchical structure controlled tough, biocompatible, mechanically tunable and printable gels for regenerative medicine. Herein we report for the first time, the detailed effects of various kinds of nanocellulose namely, bacterial nanocellulose (BC), cellulose nanofibers (CNF) and cellulose nanocrystals (CNC) on the morphology, structure–property relationship and 3D printability of the photochemically crosslinked silk fibroin/nanocellulose composite hydrogels. The hierarchical structure of fabricated hydrogels was both qualitatively and quantitatively investigated using scanning electron microscopy and small/ultra-small-angle neutron scattering; while their mechanical properties were assessed using rheology, tensile and indentation tests. The micropore size and inter-hydrophobic domain distance of fabricated hydrogels were tuned in the range of 1.8-9.2 µm and 4.5-17.7 nm, respectively. The composite hydrogels exhibit superior viscoelastic, compressive and tensile mechanical properties compared to pristine silk fibroin hydrogel; where the shear storage modulus, compression modulus, young’s modulus and tensile toughness were tuned in the range of 0.4-1.4 MPa, 1.3-3.6 MPa, 2.2-14.0 MPa and 16.7-108.3 kJ/m3, respectively. Moreover, the obtained mechanical modulus of the composite hydrogels in terms of shear, tensile and compression are comparable to articular cartilage (0.4-1.6 MPa), native femoral artery (~9.0 MPa) and human medial meniscus (~ 1.0 MPa) tissues, which demonstrate their potential for a wide range of tissue engineering application. The whisker form of nanocellulose was observed to enhance the printability of composite hydrogels, whereas the fiber form enhanced the overall toughness of the composite hydrogels and promoted the L929 fibroblast cell viability and proliferation. The results presented here have implications for both fundamental understanding and potential application of RSF/nanocellulose composite hydrogels for 3D printed scaffolds and tissue engineering.

Olefins demand has increased steadily in recent years, with a propylene demand around 100 and an expected annual growth between 3-4%. A majority of this propylene production is presently via steam cracking of naphtha but on-purpose processesbased on selective propane dehydrogenation or utilizing methanol as an intermediate are being deployed. The coal-to-propylene route in particular has gained wide interest in China. This paper presents an assessment of such emerging propylene production routes from methanol by combining detailed process simulation with life-cycle assessment and monetization. Though presenting low economic cost in terms of OPEX and CAPEX, the coal-to-propylene route has by far the highest total monetized cost when accounting for human health and ecosystem quality externalities. The natural-gas-to-propylene route is also found to have a higher total monetized cost than the conventional steam cracking of naphtha and propane dehydrogenation due to human health and resource scarcity externalities. These results highlight the importance of accounting for negative externalities in assessing the techno-economic performance of industrial processes, as it can radically change the outcome of the analysis.

Transparent paper with excellent optical transmittance and mechanical stability shows potential for use in diverse applications as a substrate. Here, we reported a novel alkyd resin-impregnated cellulose transparent (ARICT) paper that exhibited good flexibility, adequate biodegradability, easy scale-up, and tailorable wettability. As the concentration of alkyd resin increased (5-15 wt.%), the optical transmission of the cellulose paper increased from 70.7% to 93.5% at 550 nm, and its water contact angle increased from 9° to 91°. Furthermore, impregnating the cellulose paper with alkyd resin increased the surface smoothness, thermal stability, and toughness of the paper. After poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was coated on one side of the ARICT paper, a flexible single-sided conductive paper with high conductivity was obtained, while the other side retained high insulativity, suggesting that the ARICT paper was a promising substrate for the fabrication of a flexible electrode. Finally, the eco-friendly biodegradability was verified by subjecting the ARICT paper to fungal degradation over time. This study developed a new method for the fabrication of flexible and biodegradable substrates, enabling the development of disposable electronics.

We introduce a recyclable and efficient enzymatic process by integration of microwave pretreatment followed by magnetic nanobiocatalysis for the green and sustainable oilseed biorefinery. The magnetic nanobiocatalyst was prepared by immobilizing protease onto iron oxide magnetic nanoparticles and characterized using FT-IR, XRD, FE-SEM, and TEM. The optimized MW pretreatment (450W for 4 min) of fresh waste pomegranate seeds (WPS), followed by the magnetic nanobiocatalyst treatment (protease dosage of 30 U g-1 dw of WPS, pH 7 and 45°C for 10 h) recovered 17.8% of oil slightly less than hexane derived oil (18.6%) together with protein (15.9%) and dietary fibre rich (97%) solid residue as co-products. However, the magnetic nanobiocatalyst without microwave pretreatment of WPS, recovered only 13.1% oil and 11% protein even after 16 h of reaction. Excellent thermal stability and magnetic separation enabled the reuse of the magnetic nanobiocatalyst for at least 4 cycles without compromising the oil, protein, and dietary fibre recovery and protease activity. Additionally, the fatty acid composition, punicic acid and phenolics content, antioxidant activity of oil and fibre composition and functional properties (oil/water holding capacity, glucose absorption capacity, and glucose dialysis retardation index) of dietary fibre rich solid residue from each cycles were also similar.

The oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) using oxygen (1 atm) with a TEMPO and CuCl catalyst system is investigated using a range of imidazolium-based ionic liquids (ILs) and various bases at different HMF substrate loadings (10-50%). This represents the first example of HMF to DFF conversion in ionic liquid media under homogeneous catalysis conditions, revealing dramatic differences in performance between the ILs. In the non-coordinating, hydrophobic ionic liquid, [bmim][NTf2], 90% DFF yield is obtained at 5 mol% catalyst loading after 6 hours at 80 °C at a very high 40% HMF loading. Increasing the temperature to 100 °C leads to a lower yield, attributed to loss of volatile TEMPO from the reaction medium. A system using TEMPO and pyridine immobilized within the ionic liquid [bmim][NTf2] results in selective conversion of HMF to high purity DFF. It also allows the DFF formed to be isolated by sublimation in 81% yield before a further cycle is performed. Subsequent catalyst deactivation is probed by X-ray photoelectron spectroscopy (XPS). Synthesis from fructose in a two-step process achieves a 55% isolated DFF yield. This approach overcomes significant drawbacks previously reported for this transformation, such as solvent toxicity, separation and purification problems as well as the need for high oxygen pressures. Further oxidation of HMF with this system leads to a 62% yield of 5-formyl-2-furancarboxylic acid (FFCA). The separation of this compound can be achieved by sublimation of DFF followed by solvent extraction.

Carbon dioxide (CO2) is a detrimental greenhouse gas to the environment as the main contributor to global warming. However, the development of efficient methods for CO2 absorption and separation is still a great challenge. Ionic liquids (ILs) have emerged as promising solvents for CO2 separation due to negligible vapor pressure and adjustable structures. In this work, a new strategy that three superbase ILs are designed as hydrogen bond acceptor (HBA) and further combined with ethylene glycol (EG) as hydrogen bond donor (HBD) to form novel IL-based deep eutectic solvents (DESs) was proposed for efficient and reversible absorption of CO2. The results indicated that both excellent recyclability and high CO2 mass capacity up to 0.141 g CO2/g DES under 40 °C and 100 kPa are achieved by [HDBU][Im]/EG with the mass ratio of 7:3, and the value is much higher than most of reported IL-based DESs. The superior CO2 absorption and desorption performance were attributed to the synergistic interaction between both IL, EG and CO2 to form carbamate and carbonate. This work provides a feasible method for designing IL-based solvents in CO2 separation applications.

Copper-doped Co3O4 with high specific surface area has been prepared by using mesoporous silica KIT-6 as hard temple which showed exceptional catalytic performance (99% conversion of fluorene and 99% selectivity of fluorenone) for catalytic oxidation of fluorene to fluorenone using molecular oxygen as oxidant in the absence of radical initiator or other co-catalysts. Characterization results of N2 adsorption-desorption, XRD and TEM of the samples revealed the ordered mesoporous structure and increased specific surface area. XPS and O2-TPD results showed the increased surface cobalt, Co3+/Co2+ ratio, and oxygen species. The H2-TPR also indicated the redox ability could be improved by doped copper in Co3O4, which all facilitated the aerobic oxidation reaction.

To promote the electrochemical performance of Li-rich layered cathode material Li1.2(Ni1/6Co1/6Mn4/6)0.8O2, the allogenic [email protected] (1-y)[Li1.2(Ni1/6Co1/6Mn4/6)0.8O2]core∙y[Lix(Ni1/6Co1/6Mn4/6)2O4]shell are developed by the in-situ phase transformation method. The allogenic structure of the composites was characterized by X-ray powder diffraction, Raman spectroscopy, HRTEM and SAED. The obtained allogenic electrodes exhibit better initial Coulombic efficiency, higher reversible capacity and capacity retention than pristine Li-rich layered oxide. Electrochemical tests show that the electrochemical properties of the cathode material are best when the ratio of the spinel component is 3%. After 120 cycles at a rate of 0.2C, excellent reversible capacity (246 mAh g-1) and good capacity retention (94%) were obtained. Moreover, the rate performance of allogenic [email protected] composites has also been greatly improved. In particular, the sample with 3% spinel composition maintained a high discharge capacity of 120 mAh g-1 even at a high power rate of 10C. The superior electrochemical performance of the allogenic composites are owing to the three-dimensional paths of the in-situ transformed spinel phase, which offers the possibility of accelerating the Li+ diffusion and decreasing the charge transfer resistances illustrated by GITT and EIS in this work.

In our original paper,(1) we probed the catalytic ability between the same metal–organic frameworks (MOFs) with and without active Cu sites on chemical hydride ammonia borane (AB). Among our discoveries, we reported that when the open metal sites were covered by coordinated solvent dimethylformamide (DMF), ammonia was generated from the AB MOF composite ([email protected]). There were two possible explanations: (1) There was no active Cu to capture ammonia. (2) DMF destabilized AB and released ammonia in DMF-coordinated MOF. In the second case, AB spent products could be different, as MOF with DMF may break the bond between B and N easily, while MOF without DMF may keep the B–N bond. In order to confirm the mechanism, NMR was applied to clarify the products from AB. In both [email protected], they showed almost identical spectra in solid-state and solution 11B NMR. It proved that the copper open metal site may serve as an ammonia scrubber. Although it does not demolish the argument, we found that solid-state 11B NMR in Figure 6A and Figure S5 in the Supporting Information should be shifted by 20 ppm due to the wrong standard used. In the Results and Discussion: Dehydrogenation of [email protected] section, the ending of the paragraph beginning with “As ammonia was only observed...” should be modified to “Chemical shifts at 6 and 20 ppm in the solid-state 11B NMR (Figure 6A) are assigned to tetracoordinated B species of BN4 and sp2 BH groups,(2,3) which can also be observed in the solution 11B NMR (Figure 6B). The results indicate that both MOFs (regardless of copper active sites) generate the same byproducts. Boron with reduced hydrogenation after the dehydrogenation process can be seen, and there is no BH3 moiety due to coordinated DMF destabilization.” Figure 6. (A) Solid state and (B) solution 11B NMR spectra of [email protected] and [email protected]·DMF-de. Figure S5. Solid-state 11B NMR spectra of [email protected] after thermal dehydrogenation and MOF-2 after washed by THF. With the consideration of the correct standard in the solid-state NMR, we start to have a shared peak of sp2 BH groups in both solid-state and solution 11B NMR spectra and one extra peak of B sp3 groups found in solid-state NMR. It is because tetrahydrofuran (THF) used in solution NMR can only dissolve polyborazylene (PB) and makes only sp2 BH groups observable, while solid-state NMR can see more. Hence, although the revision does not alter our final conclusion (since both solid and solution NMR spectra of MOFs with and without DMF are still the same, it indicates that copper active sites in MOF are capable of ammonia removal), for research integrity purpose, we report the minor revision to our original paper. This work was supported by the Ministry of Science and Technology, Taiwan (Award MOST 104-2218-E-009-031- MY3 and Award MOST 107-2221-E-009-014). This article references 3 other publications.

The exfoliation of two-dimensional metal-organic frameworks (2D MOFs) to prepare few-layered MOF nanosheets (MONs) is of great interest in recent years. In this work, an efficient and environmentally friendly liquid-exfoliation method is developed to produce stable and high-concentration dispersions of few-layered Zn2(bim)4 MONs. Bulk Zn2(bim)4 can be successfully delaminated in ionic liquid and water mixed solvents, where the ionic liquid acted both as solvent and surfactant. The highest exfoliation rate is up to 47% with a [Omim]Cl volume ratio of 50%. In addition, the prepared Zn2(bim)4 MONs can be easily dispersed in aqueous solution and stabilize for more than two weeks. Zn2(bim)4 MONs are used as fluorescent sensor to detect metal ions in water, and exhibit enhanced sensing ability for Fe3+ than the bulk MOFs. Highly dispersive nature after delamination and easily accessible active sites on Zn2(bim)4 MON surface are all in favor of its high-performance in sensing.

Green, efficient and low energy consumption capture of CO2 from the flue gas of coal-fired power plants has been one of the most popular research topics in the world. In this work, a concept process of post-combustion capture using a choline chloride/urea (1:2) deep eutectic solvent (DES) as a physical solvent was proposed. The DES-based post-combustion capture (PCC) process is modeled and simulated using the commercial Aspen Plus simulation software. The required parameters were studied and further embedded in Aspen Plus. The simulation results show that the process has a good capture effect; the capture ratio of CO2 is 97.33%, and the purity of CO2 in the product gas is 99.42%. Through sensitivity analysis, the influence of several key parameters on the process performance is studied and reasonable operating conditions are determined. Exergy analysis is carried out for a CO2 absorption unit and a solvent regeneration unit. The results show that the total exergy efficiency of these two units is 74.28%. The new DES-based PCC process has great potential and will provide a new way to capture CO2 in the flue gas of coal-fired power plants.

The importance of size reduction to commercial deployment of biomass utilization technologies cannot be overemphasized. Size reduction is necessary to create good flowing, easily digestible lignocellulosic biomass. However, inefficiencies and inconsistencies have not been well addressed for the process of size reduction. This has motivated quite a few research studies, some of which have reported the influence of process variables and pretreatment on size reduction performance as well as the development of novel size reduction equipment and empirical mathematical models. In this paper, we present a systematic and critical evaluation of the state of lignocellulosic biomass size reduction research to provide insights for engineers and scientists in future development and/or investigation. We first briefly discuss the structural biology and failure mode of lignocellulosic biomass. Then we present a comprehensive, data-driven picture of the interactions among lignocellulosic biomass attributes, size reduction process variables, pretreatment processes, and size reduction process performance (as defined by product characteristics and size reduction energy consumption). The sizing equipment tool wear issues are also summarized. Finally, we highlighted some existing gaps and future research opportunities for lignocellulosic biomass size reduction to inform the development of newer technologies which could effectively produce high-value lignocellulosic biomass particles

The development of facile strategies and techniques to fabricate nanofiltration (NF) membrane with ideal molecular sieving ability has received growing attentions in both academia and industry. Chitosan (CS) is deemed to a promising renewable membrane material. However, the scalable and low-cost fabrication of pure CS membrane is severely limited by the poor solubility in organic solvent. Herein, a simple and effective film casting strategy is presented to prepare a positively charged CS-based NF membrane for effective rejection of dye and salt in textile wastewater. The penetration performance of CS membranes can be elaborately tuned by regulating the casting parameters during the fabrication process. The as-synthesized CS membranes with suitable thickness and tensile strength exhibit a considerable water permeance and high rejection rate up to 94.8% for CaCl2 and 87.8% for MgSO4. Especially, the CS membrane with a molecular size cut-off of 5.015 Å (hydrated radius) shows ultrahigh rejection rate of > 99% to six kinds of conventional dyes in textile wastewater. The long-time evaluation of dye and salt separation demonstrates the superior stability of CS membrane. This work aims to develop a facile and cost-effective solution to construct CS NF membrane with superhigh filtration capacity for dyes and salts removing from actual textile wastewater.

The rapid growth of discarded or landfilled thermosetting plastics has caused serious environmental issue and significant waste of energy. Selective degradation of thermosetting polymers into useful chemicals under mild conditions may provide a sustainable approach to address this challenge. In this study, we developed a green and efficient method to cleave the crosslinks of amine-cured epoxy resin (EP) to produce new functional chemicals. Complete degradation was achieved using 4 mol/L of HNO3 incubated at 60°C for 3 h and it has a higher efficiency than conventional methods. The C-N bonds of EP were selectively cleaved without breaking the skeletal bonds. The swelling-induced nanopores in the EP caused by the microwave processing exposed the crosslinks that resulted in milder degradation conditions. The porous products could be readily separated and recovered. This study demonstrates a feasible approach for the recycling of thermosetting polymers under mild conditions.