高聚物超疏水自洁表面的多尺度结构设计与注射成型制备

The design and fabrication of superhydrohpobic surfaces are inspired from the mysterious and interesting superhydrophobic phenomena in nature. People are more interested in the superhydrophobic surfaces, which would have a broad application in self-cleaning and drug reduction. The application, however, is hindered by many key issues, such as the morphology effect, the design and optimization of geometric structures, and its mass fabrication. In this proposal, firstly "learnt from the nature", the polymer superhydrohpobic surfaces will be fabricated by injection molding and PDMS molding, using the lotus leaf as a master. The geometric characteristics of these polymer surfaces will be investigated to reveal the mechanism of the superhydrobicity and self-cleaning functions of the lotus leaf. From the thermodynamic point of view, the thermodynamic model will be established for the multiscale structures. The physical mechanism, behind that the geometrical characteristics affect the superhydrophobic properties, will be explored. Then "mimicking the nature", the multiscale structures with the superhydrophobic and self-cleaning functions will be designed. These structures will be optimized after verifying their wetting properties. Finally, "improving on nature", the superhydrohpobic and self-cleaning surfaces with multiscale will be fabricated via injection molding technology. The outcomes from this proposal will provide a new idea and a new solution for the design and optimization, mass fabrication of the polymer superhydrophobic and self-cleaning surfaces. The output of this proposal will also help promoting these surfaces towards application.

自然界神秘而有趣的超疏水现象为超疏水表面的设计与制备提供灵感与启发。人们对超疏水表面的兴趣不断增加，其在表面自清洁和表面减阻等方面有着广阔的潜在应用。然而超疏水表面形貌效应、几何特征的设计与优化，以及批量化制造再现等是阻碍其应用的瓶颈所在。本研究"师法自然"，借助注射成型技术和PDMS模塑成型两种方法获取以荷叶为母版的高聚物微纳结构表面，洞察其表面的几何特征，揭示荷叶表面的超疏水自洁功能形成机理。从热力学角度出发，建立多尺度结构的热力学分析模型，探明表面几何特征对超疏水特性影响的内在物理机制。继而"模仿自然"，设计具备超疏水自洁功能的多尺度几何模型，理论验证其润湿性能，优化几何结构设计。最后尝试"超越自然"，实现超疏水自洁多尺度结构表面的注射成型制造再现。本研究为高聚物超疏水自洁表面的多尺度结构设计与优化、批量化制造提供新思路和新途径，将有助于推进高聚物超疏水自洁表面走向实际应用。

超疏水表面具有自清洁、低粘滞、防污和防腐等优良的性能，在诸如生物医学、液体输送、交通运输工具等领域有着广泛的应用前景，其中关于超疏水表面形貌效应的揭示、几何特征的设计优化和批量化的制备是其能走向实际应用的关键。通过三年间不断的努力与探索，基本上顺利完成了项目预期的各项研究内容。本项目研究了高聚物仿箬叶表面制备及功能形成机理，采用PDMS模塑成型和注射成型两种方法分别复制箬叶表面的结构，通过检测和对比成型的高聚物表面的复制质量和润湿性能，揭示超疏水自洁功能表面的形貌效应，分析两种成型方法复制微纳复合结构的可行性。基于液滴在固体表面稳态润湿状态系统相对自由能最小原理，利用热力学分析方法，以规整的一阶和二阶结构为研究对象，得到了结构几何参数对系统平衡接触角、润湿状态和润湿转换能垒的影响，为超疏水表面多尺度结构的几何设计与优化提供理论支撑。设计并搭建了微电铸成型系统和高聚物超疏水表面注射成型实验平台，实现了微结构和微纳复合结构的金属化转移和高聚物超疏水表面的高效成型制备。拓展研究了纳米结构表面对聚合物表面润湿性能的影响，以三种不同形貌和深宽比的AAO模板为模芯，采用注射成型方法制备出相应的纳米结构表面，并检测其静态接触角。深入挖掘了纳米结构型腔中聚合物熔体的充填机理，基于分子动力学方法分析了充填过程的形态演变，揭示了充填过程中聚合物分子的运动规律。项目的研究成果在高聚物超疏水表面多尺度结构设计和制备方面取得了创新性进展，有助于仿生超疏水表面走向实际应用。迄今为止，本项目已发表论文7篇，其中SCI/EI检索收录6篇，录用论文2篇，申请发明专利2项。