梯度多孔材料的仿生制备及其液体自发定向输运机制研究

The long-distance and spontaneous liquid transport is not only an important scientific question but also critical for many real applications. The liquid transport property of scaffolds is significantly related to their applications in many fields such as tissue engineering, supported catalysis, electrode, and separation. Therefore, it has been arousing more and more people’s attention. Many natural materials, such as desert beetle’s back, spider silk, and cactus’s spine, have shown excellent liquid transport ability. However, the up-to-date research is limited in gradient fiber and flat surface system and the long-distance, spontaneous liquid transport still remains a great challenge. In this project, we will try to investigate the liquid transport property of bioinspired gradient scaffold. We will start with observing and analyzing several typical natural scaffolds, and tried to summarize the relationship between their gradient structure and the liquid transporting property. Secondly, we will create biomimetic scaffolds by methods such as sphere-templating or ice-templating. Coupled with surface modification, bioinspired gradient scaffolds can be achieved and systematically investigated for their liquid transport property. Finally, we will further model such property with their architectures and surface properties. Based on these understanding, the liquid transport property of scaffolds could be tailored to better tackle the challenges of long-distance, spontaneous liquid transport.

液体的自发、定向、长程输运既是一个重要的科学问题，也有广泛的应用。多孔材料内部的液体输运性能与其在组织工程支架、催化剂载体、电极材料、过滤材料等方面的应用密切相关，正越来越受到人们的重视。经过漫长的进化，很多天然生物材料都展示出了优异的液体输运性质，如沙漠甲虫、蜘蛛丝、仙人掌等。以往的仿生研究中，液体的定向输运距离仍然较短，研究体系也不够丰富，局限在梯度纤维和平面体系。本项目拟开展基于仿生梯度多孔材料的液体输运性能研究。首先深入观察和分析几种典型的生物材料的多孔结构，总结其多孔结构与其液体输运性能之间的关系。进而利用微球法、冰模板法等，对其典型生物结构进行人工仿制，从孔隙结构和表面性质两个方面构筑仿生梯度多孔材料。在此基础上，深入研究这类仿生梯度材料的液体输运性能，建立模型，阐释多孔材料拓扑结构和表面性质对其液体输运性能的影响，并优化制备条件，实现液体的自发、定向、长程输运。

液体在三维多孔材料中的自发定向输运不仅是一个重要的科学问题，而且对组织工程支架材料、催化剂载体、电极材料、液体吸附材料等的设计和制备都具有非常重要的意义。本项目以常见植物杆的取向孔道结构和高效液体输运特性为研究对象。深入观察和分析了开运竹、白掌等几种常见的草本植物的多孔结构，阐明了其内部取向孔道结构尺寸与其液体输运性能之间的关系。基于仿生原理，利用定向冷冻技术，实现了具有取向孔道结构的多孔材料的仿生制备。通过改变冷冻速率等参数，对取向孔道结构的尺寸进行了有效调控，并对其液体自发输运特性进行了系统研究，定量阐释了取向孔道对液体自发输运速度和毛细爬升高度的影响。在此基础上，开发了具有长距离水传输和高效水挥发功能的多孔材料，为实现水的净化、再生和脱盐提供了新的思路。此外，设计和制备了具有取向结构的聚氨酯泡沫材料。利用取向孔结构的强毛细力，实现了对多种不同粘度液体的高效吸附；进一步通过调控聚氨酯的交联，实现了泡沫材料的热致收缩和液体的响应性释放，为液体的高效吸附和回收提供了新的材料设计策略。