作者：Peng Ge, Jianglei Zhang, Yongshun Liu, Shuli Wang, Wendong Liu, Nianzuo Yu, Yuxin Wu, Junhu Zhang
关键字：none
论文来源：期刊
具体来源：Adv. Funct. Mater.
发表时间：2018年

Smart pH-responsive surfaces that could autonomously induce unidirectional

wetting of acid and base with reversed directions are fabricated. The smart

surfaces, consisting of chemistry-asymmetric “Janus” silicon cylinder arrays

(Si-CAs), are prepared by precise modification of functional groups on each

cylinder unit. Herein, amino and carboxyl groups are chosen as typical

pH-responsive groups, owing to their protonation/deprotonation effect in

response to pH of the contacted aqueous solution. One side of the Si-CAs

is modified by poly(2-(dimethylamino)ethyl methacrylate), while the other

side is modified by mixed self-assembled monolayers of 1-dodecanethiol and

11-mercaptoundecanoic acid. On such surfaces, it is observed that acid and

base wet in a unidirectional manner toward corresponding directions that

are modified by amino or carboxyl groups, which is caused by asynchronous

change of wetting property on two sides of the asymmetric structures. The

as-prepared Janus surfaces could regulate the wetting behavior of acid and

base and could direct unidirectional wetting of water with reversed directions

when the surfaces are treated by strong acid or base. Due to the excellent

response capability, the smart surfaces are potential candidates to be  

applied in sensors, microfluidics, oil/water separation, and smart interfacial

design.