Cui Feichen, Zhang Yipeng, Sui Yang, Chen Hongwen, Helms Brett A, Yan Jiajun
School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Angew Chem Int Ed Engl. 2024 Dec 2;63(49):e202410862. doi: 10.1002/anie.202410862.
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.
聚合物刷的表面接枝极大地改变了表面性质，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各样的功能。将两种或更多种聚合物刷的性质结合到一个表面上，为刷改性材料开辟了更多可能性。然而，虽然通过共聚在刷上引入几种化学组成通常是可行的，但要在一个表面上改变聚合物刷的类型却具有挑战性。尽管先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的存在，但它们通常将聚合物类型限制为两种。在这里，我们提出了一种在聚合物刷根部引入动态共价二酮烯胺键的策略。在表面功能化过程中，可以精确调节接枝密度。通过添加小分子胺可以裂解表面锚定的聚合物刷。在对暴露位点进行重新功能化后，可以从表面重新接枝新的聚合物刷。这种可操作性允许调节聚合物刷的类型和密度，为制备具有混合接枝的新一代明确的刷改性材料指明了方向，在智能材料和表面设计中具有潜在应用。
