ZnO微纳米结构薄膜的光响应润湿性

Photoresponsive wettability of ZnO micro-nanostructure films

利用低温液相技术及氢氟酸的调控作用制备"短棒"、"球形"和"花形等不同形貌的ZnO微纳米结构,研究这些形貌特征的ZnO表面在真空紫外光(VUV)处理后的润湿性变化情况。结果表明,经VUV光照处理后,3种不同形貌的ZnO表面润湿性均发生从高疏水(接触角CA>120°)到超亲水的转变(CA^0°),其变化速度均经历了一个先快后慢的过程。用十八烷基三甲氧基硅烷对ZnO表面进行改性,使ZnO表面覆盖一层自组装单分子膜,则其疏水性有所增强(CA>140°);此时再经VUV光照后,ZnO表面从高疏水到超亲水的转变进程显著变缓。对各种不同微纳米结构ZnO表面进行光润湿性研究,将有助于实现ZnO基质润湿性梯度表面。

Several ZnO micro-nano structures with different morphologies, such as rods, spheres and flowers, were prepared by means of low temperature liquid method tailored by hydrofluoric acid. Their vacuum-ultraviolet （VUV） photoresponsive wettabilities were focused. With VUV illumination time aging, the wettabilities of all ZnO micro-nanostructures change from high-hydrophobic （contact angle （CA）〉 120°） to superhydrophilic （CA-0°）, and all of the water contact angles change with an uneven velocity： fast firstly, and then slowly. If the surfaces of ZnO micro-nanostructures are modified by n-octadecyltrimethoxysilane （ODS）, i. e. the surfaces are coated by a self-assembly monolayer, their water contact angles increase （CA〉 140°）. Also, it takes more time to transmit from high-hydrophobic to superhydrophilic for ZnO surfaces under VUV illumination after they are modified by ODS. All of the results can be helpful to realize ZnO-based wettability-gradient surfaces.