高分子表面多层次微/纳结构的成型新方法和调控

Hierarchical micro/nano structured surfaces, which exhibit efficient anti-reflectivity and stable superhydrophobicity simultaneously, have extensive application values in many advanced applications. Massive and reliable preparation for hierarchical micro/nano structure, however, is really challenging. This research is carried out from key scientific issues and technical level around the major problem. The related key scientific issues are investigated and analyzed in depth. They include the superimposed effects in high-shear-rate capillary rheology of polymer melt, multiscale flow simulation of melt in mold cavity with microfeature, complex nonlinear micro-deformation behavior of polymer in mold microcavities, and dynamic viscoelastic properties of polymer/supercritical fluid system. The research on the scientific issues provides the basis for solving the difficulties of accurate replication for hierarchical micro/nano structure and helps to propose the mechanisms for tuning the micro/nano structure. Then the theoretical foundation for micro/nano molding can be laid. The hierarchical micro/nano structured surfaces are designed according to the function requirement. A novel strategy is proposed, that is, micro injection molding is combined with two novel molding methods developed in this research team. They are micro injection-compression molding with a biaxial compression and micro blow molding. Using this strategy, both hierarchical micro/nano and three-dimensional micro/micro/nano structured surfaces are prepared. This research work provides the basis for massively preparing the hierarchical micro/nano structures on large area polymer surfaces under lower processing temperatures. The prepared surfaces have accurately controlled micro/nano structures and higher biomimetic functional durability, and so exhibit wide applications. This work also provides novel theories and technologies for prompting large scale and low cost applications of functional surface structures.

多层次微/纳结构兼具高效减反射和稳定超疏水，在许多先进领域有广泛的应用价值。但多层次微/纳结构的批量、可靠制备极具挑战性。本项目围绕该重大难题从关键科学问题和技术层面开展研究。深入研究、分析熔体的高剪切流变叠加效应和充模流动多尺度模拟、模腔微槽中材料发生的复杂非线性微形变行为以及高分子材料/超临界流体体系的动态黏弹性能。科学问题的研究可为解决多层次微/纳结构准确复制的难题提供基础，有助于提出调控微/纳结构的机理，奠定微/纳成型的理论基础。根据功能需求设计多层次微/纳结构，采用微注塑，引入超临界流体辅助加工，尤其首次提出“微注射双向压缩”和“微吹塑”，制备多层次微/纳和三维多层次微/微/纳两类结构。本项目可为在较低加工温度下，批量制备大表面上多层次微/纳结构参数得到准确控制、仿生功能耐久性强的高分子材料及拓宽其应用范围提供理论基础，为推动表面功能结构大规模、低成本应用提供新理论和新技术。

微、纳结构和多层次微/纳结构表面在许多先进领域有广泛的应用价值，但其批量、可靠制备极具挑战性。..主要研究内容：.1. 研究典型生物表面性能与微、纳结构和微/纳结构之间的关系；根据功能需求，设计表面微、纳结构和微/纳双级结构，采用多种方法制备相应结构的高强度模板。.2. 研究高分子材料及其复合材料的非线性流变行为和高分子材料及其复合材料/超临界流体体系的动态黏弹性能，分析温度、压力和CO2含量对高分子复合材料黏度的影响；模拟注射压缩成型中的熔体充模流动和纳米柱阵列结构表面的液滴冲击过程。.3. 构建4种测试表征装置或系统。.4. 提出快速、可批量成型表面具有微、纳结构和微/纳双级结构的高分子材料复制物的技术方案。成型表面具有微、纳结构和微/纳双级结构的系列高分子材料及其多相体系复制物，研究复制物的表面结构形貌、复制性能和精度，系统测试、分析复制物的光学性能、润湿性能、动态超疏水行为以及液滴冲击、冷凝和结冰行为等，揭示性能与表面结构之间的关系。..重要结果、关键数据及其科学意义：.1. 时间–压力–CO2含量叠加原理对高分子复合材料的有效性与基体与填料间的界面相互作用密切相关。.2. 采用上述技术方案，准确成型仿生纳米柱阵列结构、微金字塔结构和微/纳双级结构的高分子材料复制物，明显提高了陷光性能和光电转换效率等。.3. 采用上述技术方案，在高分子材料及其多相体系复制物表面准确成型微、纳结构和微/纳双级结构，提高润湿状态和动态超疏水的稳定性，缩短冲击液滴接触时间，宽范围调控黏附特性。.4. 在未经化学改性或表面涂覆的情况下，高分子材料复制物表面的纳米柱阵列结构或微/纳双级结构呈现冷凝微液滴自移除和扫掠行为，明显延长结冰时间。.据本项目组成员所知，上述结果多数是通过本项目研究首次发现和获得的。.综合上述研究结果，分析、揭示了相关机理，为设计微、纳和微/纳双级结构，以提高复制物各种性能提供理论基础。本项目为批量成型大表面上结构参数得到准确控制、仿生功能耐久性强的高分子材料复制物及拓宽其应用范围提供指导。