油水分离用超疏水纤维素基织物的制备及研究进展

近年来,石油泄漏和有机污染物排放对海洋环境和人类健康造成了严重的危害,开发高效、耐用的油水分离材料处理含油废水势在必行.纤维素基织物由于其多孔性、可再生性及优异的柔韧性在油水分离材料的制备中受到广泛的关注.本文详细介绍和讨论了各种不同方法制备超疏水纤维素基织物的研究现状,并阐述了超疏水纤维素基织物在油水分离中的应用,最...     

Application of Nano-Hydroxyapatite Derived from Oyster Shell in Fabricating Superhydrophobic Sponge for Efficient Oil/Water Separation

The exploration of nonhazardous nanoparticles to fabricate a template-driven superhydrophobic surface is of great ecological importance for oil/water separation in practice. In this work, nano-hydroxyapatite (nano-HAp) with good biocompatibility was easily developed from discarded oyster shells and well incorporated with polydimethylsiloxane (PDMS) to create a superhydrophobic surface on a polyurethane (PU) sponge using a facile solution–immersion method. The obtained nano-HAp coated PU (nano-HAp/PU) sponge exhibited both excellent oil/water selectivity with water contact angles of over 150° and higher absorption capacity for various organic solvents and oils than the original PU sponge, which can be assigned to the nano-HAp coating surface with rough microstructures. Moreover, the superhydrophobic nano-HAp/PU sponge was found to be mechanically stable with no obvious decrease of oil recovery capacity from water in 10 cycles. This work presented that the oyster shell could be a promising alternative to superhydrophobic coatings, which was not only beneficial to oil-containing wastewater treatment, but also favorable for sustainable aquaculture.     

Superhydrophobic polymer multilayers for the filtration- and absorption-based separation of oil/water mixtures

We report layer-by-layer approaches to the design of superhydrophobic and superoleophilic substrates for the filtration- or absorption-based separation of bulk oil from oil/water mixtures. Fabrication of covalently cross-linked, nanoporous polymer multilayers on mesh substrates yielded superhydrophobic and superoleophilic porous media that allow oil to pass, but completely prevent the passage of bulk water. This approach can be used to promote the filtration of oil/water mixtures, and these film-coated substrates can be bent and physically manipulated without affecting oil- and water-wetting properties. Fabrication on three-dimensional macroporous polymer pads yielded flexible objects that float on water and absorb oil at contaminated air/water interfaces. This approach permits oil to be recovered by squeezing or rinsing with solvent and the reuse of these materials without decreases in performance. These pads can also absorb oil from simulated seawater, brine, and other media representative of marine or industrial contexts where oil contamination can occur. Our results address issues associated with the design of polymer-based coatings for the separation, removal, and collection of oil from oil-contaminated water. With further development, this approach could provide low-energy alternatives to conventional remediation methods or yield new strategies that can be implemented in ways that are impractical using current technologies. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3127–3136     

三醋酸纤维素纳米纤维膜的制备及其油水分离应用

石油开采和油船运输泄露的油污污染日益突出,使得质轻、亲水疏油的油水分离材料得到广泛关注。本文在无任何添加剂条件下,以三醋酸纤维素(TCA)/N,N-二甲基乙酰胺(DMAc)溶液通过热致相分离(TIPS)制备TCA纳米纤维膜。研究了淬火时间、温度和聚合物浓度等条件对TCA纳米纤维膜形貌的影响。TCA纳米纤维膜的形貌、孔隙率和比表面积通过SEM、乙醇法和N2吸脱附表征。实验结果表明,最佳实验条件为:淬火时间180 min、淬火温度-20℃、聚合物质量分数5%,得到直径为(110±28)nm均匀纤维膜。与块状TCA流延膜相比,TCA纳米纤维膜的高孔隙率和大比表面积以及表面特殊的微/纳结构,使其水接触角由86.2°增加到137.5°。由于高疏水性和亲油性以及强烈的毛细作用,TCA纳米纤维膜的吸油容量达到21.5 g/g,分别是流延膜的20~42倍,且可快速吸收油水混合物中的油层。TCA纳米纤维膜是一种可生物降解的溢油污染清洁材料。     

Structural Changes and Activation of Cellulose by Caustic Soda Solution with Urea

Investigations on the activation of cellulose by mixed solutions of caustic soda and urea are reported. The structural effects of those solutions on various dissolving pulps are studied by ¹³C-CP/MAS-NMR spectroscopy. In a series of steeping lyes, the concentration of NaOH was varied in a range from 0% to 8% and the urea-concentration in a range from 15% to 40% at ambient temperature and −25 °C. Using solely the single NaOH or urea solutions in the concentration ranges given above, no or only minor structural changes were found. In contrast to that, the cellulose I structure was partially or completely destroyed by using the bicomponent solution with urea added to caustic soda. The structural effect of the bicomponent solutions is comparable with the effect of solely caustic soda solutions of approx. 10% to 18% NaOH. However, the ¹³C-CP/MAS-NMR-spectra from the bicomponent pretreated samples indicate a structure different from the usual ordered structures of sodium cellulose I or II, namely a special urea-NaOH-cellulose complex. The results show that for cellulose activation the NaOH concentration of the caustic soda can be remarkably reduced by adding urea. The improved activating effect of an optimized caustic soda solution with added urea was proved to be useful for the synthesis of cellulose carbamate.     

One‐Step Assembly of Phytic Acid Metal Complexes for Superhydrophilic Coatings

While of immense scientific interest, superhydrophilic surfaces are usually difficult to prepare, and preparation methods are typically substrate specific. Herein, a one‐step coating method is described that can endow superhydrophilicity to a variety of substrates, both inorganic and organic, using the coordination complexes of natural phytic acid and Fe^III ions. Coating deposition occurs in minutes, and coatings are ultrathin, colorless, and transparent. Superhydrophilicity is attributed, in part, to the high density of phosphonic acid groups. The ease, rapidness, and mildness of the assembly process, which is also cost‐effective and environmental‐friendly, points towards potential applications, such as self‐cleaning, oil/water separation, antifogging.     

纤维素基超润湿材料在油/水分离应用中的研究进展

本文总结了纤维素基材料在油/水分离方面应用的研究进展。 以不同润湿性表面在油/水分离中的应用为切入点,介绍了3种不同的纤维素基油/水分离材料, 并结合作者所在课题组的研究工作,重点介绍了智能响应型油/水分离材料。 同时也总结了纤维素基超润湿材料在油/水分离之外的应用。 文章最后展望了纤维素基超润湿材料未来的研究方向并提出了亟待解决的问题。     

Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation

We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low‐surface‐energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.     

Designing magnetic and superhydrophobic cellulose nanofibers based-aerogel for efficient oil water separation

In this work, we used cellulose nanofibers (CNF) as the skeleton, Fe₃O₄@ZnO composite particles as magnetic synergist particles, 3-(2-aminoethylamino) propyltrimethoxysilane (AS) and trimethoxy(octyl)silane (OTMS) as water-based hydrophobic modifiers to prepare magnetic and superhydrophobic cellulose nanofibers based-aerogel with low density and intricate three-dimensional structure. Fe₃O₄@ZnO confers magnetic properties (3.82 emu/g) and exceptional thermal stability (water contact angle of 150.1° at 200 °C) to the system, while the combination with OTMS/AS endows the system superhydrophobic (157.5°) and excellent mechanical properties (stress of 96.95 kPa at 80% strain). It is worth noting that in the process of modifying the system with OTMS/AS, no organic solvents and acidic substances are used in the solution. Benefiting from their synergies, the system demonstrates a notable oil absorption capacity (12.31–41.91 g/g) and outstanding oil selectivity (exceeding 90%), driven by gravity alone. Interestingly, this system, marked by its cost-effectiveness, simplicity, eco-friendliness, and heightened efficiency, holds promising prospects for diverse applications in different oil–water separation behavior and purifying industrial oil wastewater, as well as oil flooding incidents.     

Fabrication of superhydrophobic sponge with hierarchical structure and application for oil/water separation

Oil/water separation polyurethane sponge with hierarchically structured surface similar to the chemical/topological structures of lotus leaf has been successfully developed by combining mussel-inspired one-step copolymerization approach. The chemical structure, surface topography, and surface wettability of the sponge were characterized by FTIR, SEM, and contact angle experiments, respectively. The results showed that as-prepared sponge exhibited high oil absorption rate because of the expansion in oil and collapse in water of the polymer molecular brushes. Meanwhile, it also possessed high absorption capacity (20 times of the self-weight), high oil retention (93.7%), and good recyclability. It had excellent potential in practical applications.     

Synthesis of Crosslinked Polymeric Particles and Their Application for the Superhydrophobic Surfaces Using Structured Polymeric Colloids

In this study, structured colloids such as self-organized supraparticles of polymeric lattices were used as coating materials for the fabrication of superhydrophobic surfaces. Crosslinked polystyrene (PS) nanospheres were synthesized using divinylbenzene as crosslinker to prevent the organic particles from being dissolved in toluene solvent. After evaporation-driven self-assembly of PS particles inside the toluene emulsions, supraparticles of PS lattices were fabricated and coated on glass substrate, followed by the plasma treatment using CHF₃ as gas source for fluorination process. After the fluorine treatment using plasma, superhydrophobicity was assessed by measuring water contact angle. The morphologies of supraparticles and the structure of coating film were observed using scanning electron microscope, and the elemental compositions of the coating films were detected by using X-ray photoemission spectroscopy (XPS) technique. We believe that the lotus effect from the supraparticles with different two length scales made crucial contribution to the generation of superhydrophobicity after plasma treatment for the formation of superhydrophobic surfaces.     

树莓状超疏水多孔复合棉纤维的制备及油水分离性能

基于聚多巴胺（PDA）的化学性质和树莓状纳米粒子的粗糙结构,以聚多巴胺包覆的棉纤维为基底,制备了具有多重粗糙度的树莓状超疏水多孔复合棉纤维材料.通过扫描电子显微镜观察树莓状超疏水多孔复合棉纤维表面的微观形貌,PDA-SiO₂纳米粒子稳定地固定在聚多巴胺涂覆的棉纤维表面.经过氟化改性的树莓状超疏水多孔复合棉纤维具有超疏水性,水接触角为158.2°,油接触角为0°.油/水分离实验结果表明,树莓状超疏水多孔复合棉纤维对己烷/水混合物的分离效率可达99.4%以上,使用20次后仍维持较高的分离效率.同时,其具有较高的溶剂吸附能力（13~34 g/g）、重复使用性及机械稳定性,吸油能力可与硅气凝胶相媲美.     

醋酸纤维素液相色谱固定相的制备与手性拆分

在均相条件下合成了醋酸纤维素,将其涂渍在修饰硅胶表面,制备了涂渍型高效液相色谱固定相.在40MPa压力下将所得固定相装入色谱柱.在高效液相色谱正相色谱条件下,对包括醇类、羧酸类、胺类、氨基酸类及药物类的16种新型手性化合物进行了拆分试验,结果有6种手性化合物得到了分离,效果良好.     

Removal of Organic Pollutants from Water Using Superwetting Materials

The frequent occurrence of water pollution accidents and the leakage of organic pollutants have caused severe environmental and ecological crisis. It is thus highly imperative to find efficient materials to solve the problem. Inspired by the lotus leaf, superwetting materials are receiving increasing attention in the field of removal of organic pollutants from water. Various superwetting materials have been successfully generated and integrated into devices for removal of organic pollutants from water. On the basis of our previous work in the field, we summarized in this account the progress of removal of (1) floating and underwater insoluble, (2) emulsified insoluble, and (3) both insoluble and soluble organic pollutants from water using superwetting materials including superhydrophobic & superoleophilic materials, superhydrophilic & underwater superoleophobic materials, and materials with controllable wettability. The superwetting materials are in the forms of 2D porous materials, 3D porous materials and particles, etc. Finally, the current state and future challenges in this field are discussed. We hope this account could shed light on the design of novel superwetting materials for efficient removal of organic pollutants from water.     

Formation of Superhydrophobic Alumina Coating Films with High Transparency on Polymer Substrates by the Sol-Gel Method

Transparent, superhydrophobic coating films have been prepared on polymer substrates at low temperatures through the sol-gel method. Al₂O₃ gel films were prepared on poly(ethylene terephthalate) substrates from Al(O-sec-C₄H₉)₃ chemically modified with ethyl acetoacetate. A small roughness of about 20–50 nm was found to form on the surface of the Al₂O₃ gel films dried at room temperature and then immersed in hot water at 60°C. The electron diffraction measurements have shown that this roughened surface consists of pseudoboehmite nanocrystals. The coating of hydrolyzed fluoroalkyltrimethoxysilane on the Al₂O₃ gel films with the small roughness produced transparent, superhydrophobic films with contact angle for water larger than 150°.     

K2CO3活化煤矸石制备活性炭吸附剂

用Ｋ２ＣＯ３化学活化煤矸石制备适用于废水处理的活性炭吸附剂．考察了活化条件对产物的比表面、孔体积及灰分的影响．增加了前处理和后处理步骤以改善产物的性能．最佳条件下获得的活性炭吸附剂ＢＥＴ比表面达１２３６ｍ２／ｇ，孔体积０．６７９ｃｍ３／ｇ．所制得的吸附剂表面是疏水性的，对水溶液中的酚类污染物有良好的吸附性能．     

新型键合型纤维素类手性固定相的制备及安息香分离

采用六亚甲基二异氰酸酯作为键合试剂,制备了键合型纤维素3,5-二甲基苯基氨基甲酸酯手性固定相。分别往正己烷/乙醇或正己烷/异丙醇中添加四氢呋喃和二氯甲烷,系统地考察了四氢呋喃和二氯甲烷的含量对安息香外消旋体拆分的影响。实验结果表明,安息香两对映体的容量因子随二者含量的增加而降低,但分离效果变化不大,分离因子均在1.2以上。所制备的CSP在采用含有高浓度四氢呋喃(23%)、二氯甲烷的流动相进行手性分离时仍具有良好的稳定性。与涂敷型固定相相比,流动相选择范围更广。