超疏水大豆蛋白膜的表面多级微纳结构设计与性能调控

Ease of processability, abundant resource and environmental friendliness are just a few of many reasons for the recent explosive interests in biomass materials. Among a great deal of natural polymers, soy protein isolate (SPI) is undoubtedly one of the most important materials due to its extremely high protein content and excellent physicochemical properties. Different kinds of materials, therefore, have been made of soy protein, such as hydrogels, films, plastics, and fibers. Nevertheless, SPI-based materials are hard to be employed in real applications unless its drawbacks, poor water resistance and high stiffness, were solved. Different strategies, up to now, have been explored to overcome the limitations, such as physical blending, chemical cross-linking and irradiation treatment. However, water sensitivity and barrier property are still not well addressed by using hydrophilic polymers to blend with SPI, while poor interfacial adhesion and compatibility are still core issues need to be solved for the blends of SPI and hydrophobic polymers. Chemical cross-linking and irradiation treatment, involving in using low molecular weight aldehydes with strong toxicity and resulting in remarkable protein denaturations, are restricted in food industry and biomedical application.. Inspired by the superhydrophobicity of lotus leaves, wings of butterfly, and legs of water strider, whose surfaces show combined micro/nanometer scale roughness and are of low surface energy, modification of cobalt hydroxide and copper with fatty acids can develop superhydrophobic films with uniform micro/nanostructures of nanopin and flower. Moreover, fatty acids exhibited good hydrophobicity and oxygen barrier property, which were used to improve water resistance and mechanical property of some hydrophilic polymers. Therefore, properties of SPI-based materials are desired to be remarkably improved if a hierarchical micro/nanostructured surface was constructed, which has not been reported so far. . In this project, we propose to develop superhydrophobic SPI films by inducing a control crystallization of fatty acids on the surface to construct hierarchical micro/nanostructures, and obviously improve the properties of resultant SPI films on the basis of well keeping the primary and second structures of SPI. The effects of the structure of fatty acid and crystallization condition on the surface microstructure and properties of SPI films will be investigated, and the key technology to control the surface hierarchical micro/nanostructure as well as superhydrophobic property will be presented, establishing the relationship among the fatty acid structure, surface morphology and properties of SPI films. This project is desired to overcome some drawbacks of present researches on SPI and provide a novel design concept as well as technical approaches for protein films with high performances, which is of great significance for development and applications of biomass materials.

大豆分离蛋白（SPI）材料的过度水敏感性及吸水后力学性能的急剧恶化是制约其应用的主要原因，而利用微纳米尺度多级结构控制这一有效方法构建具有表面超疏水特性SPI膜的研究至今仍是一片空白。因此，本项目提出选择表面能较低的脂肪酸作为改性剂，通过其在SPI膜表面的结晶调控，制备出表面具有可控多级微纳结构的超疏水材料；系统研究脂肪酸链结构与结晶条件控制对SPI膜表面微观形貌特征的影响规律，揭示调控多级微纳结构形成的关键技术；在此基础上，重点探讨材料表面微观形貌与润湿性能之间的关系，阐明SPI膜表面超疏水性的本质机理；通过研究脂肪酸分子结构和材料表面微观结构变化对吸水/吸湿性能、透光性能、力学性能、气体阻隔性能和生物降解性能的影响，建立润湿性能与其它性能之间的内在联系，为研制出具备优异综合性能的SPI膜提供科学依据，对于丰富新型高性能蛋白材料的研究及促进生物基高分子材料的发展有重要意义。

本项目以大豆蛋白（SPI）为基体，采用多种简单温和的改性方法在其表面构建基于多种无机材料的多尺度微纳结构，并在此基础上用低表面能化学物质进行表面修饰，制备了具有超疏水自清洁性能的蛋白膜材料。系统研究了制备条件对膜表面微结构的影响规律，并进一步考察了微结构变化与其润湿性能、透明性能、力学性能、耐酸碱和耐有机溶剂性能、自清洁性能等的内在联系，提出了SPI膜材料超疏水表面的形成机理。利用SPI自身的荧光性质及对其表面的差异化亲疏水区域构建，探讨了其作为集水和耐候发光材料使用的可行性。通过本项目研究，我们在SPI膜表面多级微纳结构构建、微观形貌及材料表面润湿性控制等方面获得了系统结果，为新型蛋白基功能材料的研究提供了科学依据，同时为生物基材料的改性与功能化研究提供了设计新思路和技术途径。. 本项目已经完成了预期研究目标，目前已在Chemical Communications、ACS Applied Materials & Interfaces、Chemical Engineering Journal、ACS Sustainable Chemistry & Engineering等SCI收录期刊上发表论文13篇，其中第一标注8篇，第二标注5篇；申请中国发明专利2项。培养博士1人，硕士2人（其中1人在读）。