(382ai) Novel and Scalable Approach to Biphilic Patterned Surface for Water Condensation Heat Transfer

Song, J., Hong Kong University of Science and Technology
Yeung, K. L., The Hong Kong University of Science and Technology
Superhydrophobic-superhydrophilic patterned surface is widely investigated due to its combination of fast water nucleation and efficient droplet departure, which are important factors to lower interfacial thermal resistance and then enhancing water harvesting efficiency. Preparation methods used nowadays are photolithography, inkjet printing, sol-gel and so on, which either involves complicated and non-scalable procedures or is not able to prepare well-defined patterns. This work demonstrates a facile surface engineering method to prepare superhydrophilic patterns on superhydrophobic substrate which is grown with closely packed TiO2 nanorods. The pattern size can be well controlled by using different masks under UV shinning. With different UV irradiation time, patterns with microscale and nanoscale sizes are able to prepare. The relationship between pattern size and its water harvesting efficiency is studied. Preliminary result shows that the water collection rate of biphilic patterned surface can achieve as high as 3 times to that of unmodified Ti foil providing a promising way to address water issue in arid regions. The biphilic patterned surface can last for more than 80 days without degradation.