Effect of polyethylene glycol on hydrophilic TiO2 films: Porosity-driven superhydrophilicity
Effect of polyethylene glycol on hydrophilic TiO2 films: Porosity-driven superhydrophilicity
复制标题
DOI：
10.1016/j.surfcoat.2010.03.030
复制
发表时间：
2010-09-15
影响因子：
5.4
通讯作者：
Chen, Huanqin
中科院分区：
文献类型：
--
作者：
Huang, Weixin;Lei, Ming;Chen, Huanqin
以聚乙二醇(PEG)2000为模板剂，采用溶胶-凝胶法合成多孔TiO2薄膜。当 PEG 含量高于临界值时，由于裂纹生长而产生的纳米孔最终在表面形成。令人惊讶的是，当 PEG 量增加到 0.02 M 后，稳定的孔结构消失，表面变得波动和开裂。此外，为了解释这种超亲水行为，提出了两个主要假设，即 Wenzel 和 Cassie 润湿浸渍模型。此外，还研究了这两种润湿方式之间的转变，并讨论了 Cassie 浸渍润湿表面的设计和构造标准。研究发现，随着 TiO2 表面孔深度的增加，可以轻松实现 Cassie 态从 Wenzel 态的转变。对多孔薄膜上 Wenzel 和 Cassie 浸渍润湿机制之间转变的研究为超亲水表面的设计提供了有价值的孔隙驱动润湿性润湿机制。 (C) 2010 Elsevier B.V. 保留所有权利。
Polyethylene glycol (PEG) 2000 was used as a templating reagent to synthesize porous TiO2 thin film by sol-gel process. The nanopores resulting from the presence of growing cracks were ultimately formed on the surface when PEG content was higher than the critical value. Surprisingly, stable pore structure disappeared and surface became fluctuating and dehiscent after PEG amount increased to 0.02 M. Besides, two main hypotheses were proposed in order to explain this superhydrophilic behavior, namely the Wenzel and Cassie wetting impregnating models. Furthermore, the transition between these two wetting regimes was investigated and the criteria for the design and construction of Cassie impregnating wetting surface was also discussed. It was found that Cassie state shifting from Wenzel state could be easily achieved with increasing hole depth on TiO2 surface. The study of transition between Wenzel and Cassie impregnating wetting regimes on porous films provides valuable wetting mechanism of porosity-driven wettability for the design of superhydrophilic surfaces. (C) 2010 Elsevier B.V. All rights reserved.