Self-healing block copolymer films - from mechanistic understanding towards applications in coatings and membranes

该合作项目的重点是制备具有自修复能力的（可逆）交联嵌段共聚物薄膜，以及其作为纳米结构涂层或先进功能膜材料的概念验证应用。作为实现自修复特性的策略，我们通过呋喃和马来酰亚胺单元之间的Diels-Alder（DA）化学采用温度依赖性共价交联。在自修复应用中使用嵌段共聚物和部分三嵌段三元共聚物是解决此类材料中的固有问题之一的一种可能性：平滑和动态链段与强且可逆的网络形成能力的组合。我们已经证明，在侧链中含有马来酰亚胺和呋喃单元的统计共聚物以及含有聚（糠基缩水甘油醚）（PFGE）片段的嵌段共聚物代表了此类应用的有前途的候选者。通过这个项目，我们将这个初步研究扩展到三嵌段共聚物和三嵌段共聚物结构（阿坝和ABC），特别是具有两个可以独立交联的链段的系统（例如，通过聚二烯的UV交联和PFGE的DA化学）或其中存在两种互补的基序（阿坝 * -固有交联作为添加单独交联剂的替代物）。此外，当我们处理具有在本体中经历相分离成不同形态的能力的嵌段共聚物时，我们以螺旋体形态为目标，以生成具有不同片段之间的高内部界面的材料，并评估对自修复特性的影响。此外，嵌段序列（阿坝 * vs. AA*B）或交联剂类型的变化将允许对潜在机制获得更深入的了解。如此产生的嵌段共聚物膜将在第一研究中用作纳米多孔膜中的选择性分离层或用作亲水-疏水涂层，例如，以防止生物污染。

This cooperation project focuses on the preparation of (reversibly) crosslinked block copolymer films with self-healing capabilities and their proof-of-concept application as nanostructured coatings or in advanced functional membrane materials. As strategy to implement self-healing characteristics, we employ temperature-dependent covalent crosslinking via Diels-Alder (DA) chemistry between furan and maleimide units. The use of block copolymers and, in parts, triblock terpolymers, in self-healing applications is one possibility to address one of the inherent problems in such materials: The combination of smooth and dynamic segments with the capability of strong and reversible network formation. We have already demonstrated that statistic copolymers containing maleimides and furan units in the side chain as well as block copolymers containing poly(furfuryl glycidyl ether) (PFGE) segments represent promising candidates for such applications. With this project, we expand this preliminary studies to triblock copolymer and triblock terpolymer architectures (ABA and ABC), in particular systems which feature two segments which can be independently crosslinked (e.g., by UV crosslinking of polydienes and DA chemistry of PFGE) or where two complementary motives are present (ABA* - intrinsic crosslinking as an alternative for the addition of a separate crosslinker). Furthermore, as we deal with block copolymers which have the ability to undergo phase separation in the bulk into different morphologies, we target a gyroid morphology to generate materials with a high internal interface between unlike segments and to evaluate the effects on the self-healing characteristics. In addition, variations of the block sequence (ABA* vs. AA*B) or the type of crosslinker will allow to gain deeper insights into the underlying mechanism. The so-generated block copolymer films will be employed in first studies as selective separation layer in nanoporous membranes or as hydrophilic-hydrophobic coatings, e.g., to prevent biofouling.