RESUMO
Fabrication of functional surfaces with designed patterns of different hydrophilicity has potential applications in active control of water droplets and water harvesting. For practical applications, the fabrication process needs to be applied to a large area in a cost-effective manner. Herein, we report the fabrication of a polymer brush of 2-(tert-butoxycarbonyloxy)ethyl methacrylate having a BOC-protected hydroxy group. The deprotection of the BOC group converts poly(2-(tert-butoxycarbonyloxy)ethyl methacrylate) (PBHEMA) into poly(2-hydroxyethyl methacrylate) (PHEMA) and hence changes the hydrophilicity. The chemical transformation changes the refractive index and thickness of the brush. This simple chemistry enables easy formation of the boundary of different hydrophilicity. Last, we demonstrate that the shape of the water droplet can be manipulated on the designed surface having different hydrophilicity.
RESUMO
Two-dimensional (2D) layered semiconductors are a novel class of functional materials that are an ideal platform for electronic applications, where the whole electronic states are directly modified by external stimuli adjacent to their electronic channels. Scale-up of the areal coverage while maintaining homogeneous single crystals has been the relevant challenge. We demonstrate that wafer-size single crystals composed of an organic semiconductor bimolecular layer with an excellent mobility of 10 cm2 V-1 s-1 can be successfully formed via a simple one-shot solution process. The well-controlled process to achieve organic single crystals composed of minimum molecular units realizes unprecedented low contact resistance and results in high-speed transistor operation of 20 MHz, which is twice as high as the common frequency used in near-field wireless communication. The capability of the solution process for scale-up coverage of high-mobility organic semiconductors opens up the way for novel 2D nanomaterials to realize products with large-scale integrated circuits on film-based devices.
