Light-Controlled Directional Liquid Drop Movement on TiO2 Nanorods-Based Nanocomposite Photopatterns

详细信息    查看全文

• 作者：Francesca Villafiorita Monteleone ; Gianvito Caputo ; Claudio Canale ; P. Davide Cozzoli ; Roberto Cingolani ; Despina Fragouli ; Athanassia Athanassiou
• 刊名：Langmuir
• 出版年：2010
• 出版时间：December 7, 2010
• 年：2010
• 卷：26
• 期：23
• 页码：18557-18563
• 全文大小：899K
• 年卷期：v.26,no.23(December 7, 2010)
• ISSN：1520-5827

文摘

Patterned polymeric coatings enriched with colloidal TiO₂ nanorods and prepared by photopolymerization are found to exhibit a remarkable increase in their water wettability when irradiated with UV laser light. The effect can be completely reversed using successive storage in vacuum and dark ambient environment. By exploiting the enhancement of the nanocomposites hydrophilicity upon UV irradiation, we prepare wettability gradients along the surfaces by irradiating adjacent surface areas with increasing time. The gradients are carefully designed to achieve directional movement of water drops along them, taking into account the hysteresis effect that opposes the movement as well as the change in the shape of the drop during its motion. The accomplishment of surface paths for liquid flow, along which the hydrophilicity gradually increases, opens the way to a vast number of potential applications in microfluidics.