Hydrophilic Amorphous TiO2/SiO2 Thin Film and Its Application to Falling Film Heat Exchangers
XU Ke, QI Chun-Hua, FENG Hou-Jun, LV Qing-Chun
(1Institute of Seawater Desalination and Multipurpose Utilization, State Oceanic Adiministration, Tianjin, 300192;
2National Engineering Technology and Research Center for Seawater Utilization, Tianjin, 300192)
Abstract The hydrophilic amorphous TiO2/SiO2 thin film was prepared by sol-gel technique for an application to falling film heat exchanger. The crystal structure of TiO2/SiO2 composite xerogel was analyzed by thermogravimetry/differential scanning calorimetry (TG/DSC) and X-ray diffraction (XRD). The heat treatment process and wet/dry cycles were investigated to improve the wettability and heat transfer performance of the thin film, which were characterized by measuring the water contact angle and heat transfer rate of falling film heat exchanger. It showed that the structure of TiO2/SiO2 composite film was amorphous after heat treatment at 200 ℃. When the subsequent wet/dry cycles was 6 or more, the water contact angle of the amorphous film could be decreased to about 10 °. Moreover, the good wettability of heat transfer tube coated with amorphous TiO2/SiO2 thin film would obviously enhance the heat transfer efficiency of falling film heat exchanger.
XU Ke, QI Chun-Hua, FENG Hou-Jun, LV Qing-Chun .Hydrophilic Amorphous TiO2/SiO2 Thin Film and Its Application to Falling Film Heat Exchangers[J] Chemcial Industry and Engineering, 2012,V29(4): 58-62
2012, Vol. 29 
