Engineering modifiers bearing benzophenone with enhanced reactivity to construct surface microstructures

Abstract

Surface microstructures with desirable functions are a critical factor that influence the performance of microdevices. Modification of surfaces with polymer modifiers is a popular and effective way to develop surface microstructures. However, constructing a patterned surface with controllable thickness is still a challenge for common modification methods. In this work, we propose a novel strategy to increase the graft efficiency of a benzophenone (BP)-capped modifier via tuning the chain backbone, so that the coated molecules can be chemically preserved and the thickness of the functional layer is controllable. Modifiers with a single BP end-group were designed and synthesized by using polyether (BP-CO), alkyl (BP-C), and perfluoroalkyl (BP-CF) as the chain backbone, respectively. For the modified layer, a graft efficiency of 91% was obtained by using BP-CO, which is over ten times higher than that of BP-C and BP-CF, making the layer thickness up to micrometers. Two hydrophilic polymer modifiers (BPEG and BPS) with the main chain composed of polyether and polyolefin were also prepared. Compared to BPS, a modified layer based on BPEG showed obvious anti-platelet adhesion and constructed a patterned surface with controllable thickness easily. This simple and effective strategy could provide new insights into designing modifiers to build a functional surface microstructure.