上海科技大学严佳骏团队报道了具有动态共价键的可重写表面接枝聚合物刷。相关研究成果于2024年8月15日发表在《德国应用化学》。

聚合物刷的表面接枝极大地改变了表面性能，包括润湿性、相容性、响应性等。通过不同类型的聚合物，可以在表面引入各种功能。将两种或多种聚合物刷的特性结合到一个表面上，为刷改性材料开辟了更多的可能性。

然而，虽然通过共聚沿刷子引入几种化学成分通常是可行的，但沿表面改变聚合物刷子的类型是具有挑战性的。尽管之前的研究已经通过正交聚合技术或部分失活/再接枝证明了二元刷子，但它们通常将聚合物类型的数量限制在两种。

该文中，研究人员提出了一种在聚合物刷根部引入动态共价二酮胺键的策略。接枝密度可以在表面功能化过程中精确调节。通过添加小分子胺来裂解表面锚定的聚合物刷。在暴露部位重新功能化后，可以从表面重新移植新的聚合物刷。

可操作性能够调整聚合物刷的类型和密度，为制备新一代具有混合移植物的定义明确的刷改性材料指明了方向，这些材料在智能材料和表面的设计中具有潜在的应用。

附：英文原文

Title: Rewritable Surface-Grafted Polymer Brushes with Dynamic Covalent Linkages

Author: Feichen Cui, Yipeng Zhang, Yang Sui, Hongwen Chen, Brett A. Helms, Jiajun Yan

Issue&Volume: 2024-08-15

Abstract: Surface grafting of polymer brushes drastically modifies surface properties, including wettability, compatibility, responsiveness, etc. A broad variety of functionalities can be introduced to the surface via different types of polymers. Bringing together properties of two or more types of polymer brushes to one surface opens up even more possibilities in brush-modified materials. However, while it is generally feasible to introduce several chemical compositions along the brushes via copolymerization, it is challenging to vary the types of polymer brushes along a surface. Although previous studies have demonstrated binary brushes via orthogonal polymerization techniques or partial deactivation/regrafting, they commonly limit the number of polymer types to two. Here, we propose a strategy to introduce dynamic covalent diketoenamine linkages at the root of polymer brushes. The grafting density could be precisely tuned during surface functionalization. The surface-anchored polymer brushes were cleaved by the addition of small molecule amines. New polymer brushes can be regrafted from the surface following refunctionalization of exposed sites. The maneuverability allows tuning of the types and densities of the polymer brushes, pointing the way to the preparation of a new generation of well-defined brush-modified materials with mixed grafts, with potential applications in the design of smart materials and surfaces.

DOI: 10.1002/anie.202410862

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202410862