Light-triggered polymer diffusion in anisotropic multizone films

该项目旨在了解各向异性离子交联聚合物薄膜中聚合物间的相互作用。一层接一层的自组装将用于制造多区聚电解质薄膜，其中具有高聚合物迁移率的“液化”区与具有低聚合物迁移率的“冻结”区分开，形成扩散屏障。聚合物的迁移率将根据分子量进行调整，从而使所有区域的化学成分保持相同。聚合物和外部负载的蛋白质在“液化”区之间的交换将由红外光引起的屏障局部中断触发。为此，光响应微珠将集成到屏障中，并将作为扩散门，在光照射下可逆地在相变时坍塌。将研究薄膜结构和力学性能、聚合物间相互作用（聚电解质间和聚电解质-蛋白质）、聚合物扩散和复合微珠的光响应（pNIPAM-Au@nanorod）。本文将讨论均相聚合物薄膜的成膜机理和非均相结构的制备。除了对基础研究有很大的影响外，未来这种薄膜还可以用于对结构聚合物网络的组成和动力学进行（外部）控制。

The project addresses understanding of inter-polymer interactions in anisotropic ionically crosslinked polymer films. The layer-by-layer self-assembly will be employed to create multizone polyelectrolyte films with “liquefied” zones with high polymer mobility separated by “frozen” zones with low polymer mobility presenting a diffusion barrier. The polymer mobility will be tailored by the molecular weight, which allows to keep the chemical composition the same for all zones. The exchange of polymers and externally loaded proteins between “liquefied” zones will be triggered by local interruption of the barrier induced by IR-light. For this purpose, light-responsive microbeads will be integrated into the barrier and will work as diffusion gates, which reversibly collapse at phase transition upon light irradiation. Film structure and mechanical properties, inter-polymer interactions (inter-polyelectrolyte and polyelectrolyte-protein), polymer diffusion, and light response of composite microbeads (pNIPAM-Au@nanorod) will be studied. The mechanism of film formation and fabrication of heterogeneous structures from homogeneous polymer films will be considered. Besides a high impact for fundamental research, in future the films might be employed for (external) control over composition and dynamics in structured polymer networks.