(180p) Superhydrophobic Nanorod Arrays for Enhancing Water Condensation Heat Transfer

Authors: 
Song, J., Hong Kong University of Science and Technology
Yeung, K. L., The Hong Kong University of Science and Technology
Water scarcity is a severe problem with increasing population growth and global climate change. To condense moisture in the atmosphere efficiently is a promising way to satisfy the growing fresh water need. Instead of using conventional substrates copper and aluminum, this work presents a new Titanium-based material to achieve ultraefficient water harvesting performance. Closely packed TiO2 nanorod arrays are grown on the titanium plate and coated with superhydrophobic monolayer. Moisture condensed on the superhydrophobic nanostructured surface will form small water droplets (< 100µm) and spontaneously jump out of surface, which can achieve higher heat transfer efficiency compared to film-wise condensation. Deep investigation on the geometric parameters (height, length and density) of TiO2 nanorods reveals their respective roles on enhancing water condensing process, providing idea to find ideal nanostructure, and finally the water harvesting capability of superhydrophobic TiO2 nanorods sample can be improved up to 260% compared to untreated titanium substrate. Water collected were analyzed to be safe for consumption. Moreover, due to the photocatalytic property of TiO2, this material can be self-cleaned and sustainably used.