Facile fabrication of biomimetic superoleophobic composite coating via Schiff base reaction and self-assembly

https://doi.org/10.1016/j.porgcoat.2020.105568Get rights and content

Highlights

  • The superoleophobicity of composite coating could be effectively controlled by adjusting the times of self-assembly.

  • The drawback of superoleophobic cotton fabric with poor friction resistance was solved.

  • The limitation of traditional methods of using additional nanoparticles to construct hierarchical rough surface for fabricating superoleophobic coating was overcame.

  • The weak interfacial adhesion between the substrate surface and the low surface tension material was overcome.

Abstract

Inspired by the defects of superoleophobic surface with poor friction resistance and the complicated preparation method, the bio-dopamine was utilized and the friction-durable superoleophobic composite coating was successfully obtained via Schiff base reaction and self-assembly. Dopamine contains the phenolic hydroxyl groups that can react with an amine group or a thiol group. Polydopamine is formed via dopamine self-polymerization under aerobic and weakly alkaline conditions. Additionally, polydopamine can adhere to the surface of virtually all materials. First, the self-polymerization of folic acid induced dopamine to form polydopamine micro-nanoparticles under weakly alkaline conditions. Second, 3,5-Bis(trifluoromethyl)aniline reacted with the phenolic hydroxyl groups of polydopamine nanoparticles via Schiff base reaction. Ammonium hexafluorosilicate was adsorbed on the surface of polydopamine microspheres via electrostatic interactions. Then, the self-assembly behavior of fs-81 and fs-63 with ammonium hexafluorosilicate occurred on polydopamine nanoparticles via electrostatic interactions. Accordingly, the surface roughness was further increased, for which the limitation of traditional methods of using additional nanoparticles to construct hierarchical rough surface was broken. Eventually, the superoleophobic composite coating was applied to the surface of cotton fabric. The results showed that the contact angles of the cotton fabric surface with edible oil, ethylene glycol and glycerol were greater than 150° in the air, respectively, after two cycles of self-assembly modification. The contact angles between the cotton fabric surface and edible oil droplets were still greater than 150°after 25 mechanical abrasion cycles. In addition, the surface free energy of cotton fabric was decreased by 64.1 % after finishing the coating.

Introduction

The research of the wettability of the materials surface had remarkable development in the past few years. Inspired by lotus leaf, the self-cleaning materials have attracted much attention due to the high value of potential industrial applications [1,2]. Due to the fact that superoleophobic composite coating with the characteristic of self-cleaning can effectively avoid the formation of stains on the surfaces. Therefore, it can be applied in the fields of oil-water separation and anti-oil stain [3,4]. The contact angle between the superoleophobic composite coating of materials surface and low-surface-tension droplets is higher than 150° with a low rolling angle [5]. There are some superhydrophobic phenomena in nature [6]. However, superoleophobic phenomena are rarely observed [7,8]. Therefore, the preparation of superoleophobic surface has far-reaching significance over superhydrophobic surface in scientific research and practical applications [9]. Additionally, organic liquids have low surface tension and easily spread on solid surfaces, which makes it difficult to fabricate superoleophobic surface [10,11]. Roughness plays an important role in the preparation of superoleophobic or superhydrophobic surface. Therefore, many methods for utilizing the additional nanoparticles to construct the rough surface were reported. For instance, Baba et al. prepared PS-SiO2 composite superhydrophobic films by utilizing silica nanoparticles to construct the rough surface [12]. Jiao et al. employed the palladium particles to endow the surface of electrospun fibers with certain roughness [13]. In addition, the rough surface is able to be obtained by self-assembly method [14,15]. However, there is a drawback that the nanoparticles are gradual off easily. As a result, it is one of the vital challenges to endow materials surface with durable roughness. At present, some methods have been applied to fabricate superoleophobic surfaces, such as etching and anodic oxidation [16], templating [17] and plasma technology [18,19]. Unfortunately, the hierarchical micro- and nanostructure of superoleophobic surface is damaged easily in terms of the weak interfacial adhesion between micro- and nanoparticles and the substrate surface. Inspired by mussels, the bio-dopamine was utilized in this paper to solve the problem mentioned above by supplying enough adhesion. Over the last decade, dopamine was extensively employed in various fields [[20], [21], [22]].

Superoleophobic surfaces have attracted much attention based on the massive market value and potential applications. In recent years, although great achievements have been made in the research of superoleophobic surfaces, the development is still in its infancy and still faces some major challenges [23,24]. First, the formation mechanism of the superoleophobic system still needs further study. Second, most of the superoleophobic surfaces prepared at present have only been in the experimental stage, which cannot fulfill the needs of large-scale industrial applications. Third, the use of superoleophobic surfaces in harsh environments still needs to be improved, including resistance to seawater acidity and alkalinity, salinity, friction, frost, etc. In addition, oil resistance is frequently limited to surfaces submerged in water, such as fish scales [25]. At present, the published preparation of superoleophobic surfaces usually adopts fluorine-containing acrylate-based, fluorine-containing polyurethane-based polymers and fluorine-containing substances [[26], [27], [28]], which inevitably bring potential risks to human and social environments. In addition, there are some drawbacks, such as the expensiveness of the preparation cost.

Based on the characteristics of strong adhesion and the secondary reaction platform from dopamine [29,30] and the difficulties mentioned above, the bio-dopamine, fluorine-containing small molecule and fluorine-containing surfactants were employed to fabricate friction-durable superoleophobic composite coating. First, by means of the self-aggregation of folic acid, dopamine was induced to form polydopamine micro-nanoparticles under weak alkaline conditions and deposited on the cotton fabric surface. Second, based on the dual driving forces of the Schiff base reaction and layer-by-layer self-assembly, 3,5-bis(trifluoromethyl)aniline, hexafluorosilicate amine, fs-81 and fs-63 were utilized to construct a hierarchical rough surface structure on the cotton fabric surface. Meanwhile, the surface energy of the fabric was reduced. Eventually, the superoleophobic-superhydrophilic composite coating was applied to the surface of the cotton fabric. The results showed that the decorated cotton fabric had the excellent superoleophobic performance after two self-assembly treatments. The contact angles of the cotton fabric surface with edible oil, ethylene glycol and glycerol were greater than 150°in the air, respectively. Moreover, the fabric still has superoleophobic characteristic after 25 abrasion cycles. The surface free energy of cotton fabric was decreased by 64.1 % after finishing the coating. In addition, the breaking strength and breathability of modified cotton fabric were decreased by 8 % and 10 %, respectively.

Section snippets

Materials

Plain weave cotton fabric was purchased from Wuxi First Cotton Textile Co. Ltd. Dopamine hydrochloride and 3,5-bis(trifluoromethyl)aniline were obtained from Aladdin. Tris(hydroxy)aminomethane, ammonium hexafluorosilicate, ethylene glycol and glycerol were obtained from Chemical Reagent Co. Ltd. of China Pharmaceutical Group. Fs-81 and fs-63 (fluorine-containing anionic surfactants) were obtained from Guangzhou Jinshengjie Chemical Co. Ltd. Edible oil was purchased from Golden Dragon Food Ltd.

The preparation of superoleophobic solution

Analysis of the factors of affecting surface wetting performance of composite coating of the cotton fabric surface

The superoleophobic composite coating was applied to the surface of the cotton fabric and the oil droplets appeared in the shape of a ball, as shown in Fig. 2.

First, we investigated the effects of the concentration of fs-81 and fs-63 and the number of self-assembly treatments on the oleophobicity of cotton fabrics surface.

It is shown in Fig. 3(a) that the contact angle between the fabric surface and oil droplets increased with increasing concentrations of fs-81(fluorosurfactant) when the

Conclusions

The main conclusions from this work are as follows:

  • (1)

    The superoleophobic composite coating is successfully obtained by a facile approach and applied to the cotton fabric surface. Moreover, the superoleophobicity of the cotton fabric surface is reserved after 25 mechanical abrasion cycles, indicating that the drawback of superoleophobic cotton fabric with poor friction resistance is solved. Meanwhile, the weak interfacial adhesion between the substrate surface and the low surface tension material

Declaration of Competing Interest

The authors declare no competing financial interest.

Acknowledgement

The authors thank the financial support of the National Natural Science Foundation of China (No. 31600478), the Natural Science Foundation of Jiangsu Province of China (BK20140145), the Fundamental Research Funds for the Central Universities (JUSRP51718A), the Priority Academic Program Development of Jiangsu Higher Education Institutions ([2014]37).

References (33)

  • Y. Lu et al.

    Preparation of superoleophobic and Superhydrophobic titanium surfaces via an environmentally friendly electrochemical etching method

    Sustainable chemistry&Enigeering, ACS Sustainable Chem. Eng

    (2013)
  • Z.H. Hu et al.

    Deciphering buried air phases on natural and bioinspired superhydrophobic surfaces using synchrotron radiation-based X-ray phase-contrast imaging

    Npg. Asis. Materials

    (2016)
  • A.K. Kota et al.

    Hierarchically structured superoleophobic surfaces with ultralow contact angle hysteresis

    Adv. Mater

    (2012)
  • D. Wang et al.

    Engineering a titanium surface with controllable oleophobicity and switchable oil adhesion

    J. Phys. Chem. C

    (2010)
  • Y.X. Wang et al.

    Wear-resistant and antismudge superoleophobic coating on polyethylene terephthalate substrate using SiO2 nanoparticles

    ACS Appl. Mater. Interfaces

    (2015)
  • A. Tuteja et al.

    Robust omniphobic surfaces

    P. Natl. Acad. Sci. USA

    (2008)
  • Cited by (10)

    • Facile preparation of hybrid coating-decorated cotton cloth with superoleophobicity in air for efficient light oil/water separation

      2022, Surfaces and Interfaces
      Citation Excerpt :

      The peak at 3363 cm−1 is the -OH stretching vibration of intermolecular hydrogen bond broadening. There was a weak absorption peak at 1223 cm−1 on account of the vibration of C-O groups [38]. The peak at 815 cm−1 was owing to the benzene ring, which showed that dopamine experiences oxidative self-polymerization under weak alkaline conditions [38].

    • Research progress in superoleophobic surface

      2023, Cailiao Gongcheng/Journal of Materials Engineering
    View all citing articles on Scopus
    View full text