Experimental study of transient evaporation characteristics of hydrophilic TiO2 ammonia water nanodroplets

To reveal the microscopic mechanism of heat and mass transfer during droplet evaporation enhanced by hydrophilic TiO2 nanoparticles, the evaporation pattern of ammonia water based nanodroplets is investigated by visualization experiments, and the initial contact angle and morphological changes of different droplets are compared in this paper. The results show that the addition of hydrophilic nanoparticles at a substrate temperature of 20 degrees C is favorable for the droplets to obtain a smaller initial contact angle. In addition, the nanodroplets remain fixed for a longer period compared to ammonia water droplets. At a substrate temperature of 35 degrees C, the pinning effect of nanodroplets is prominent at high concentrations for a long time, but the average evaporation rate reaches a negative growth rate compared to low nanoparticle concentrations. At higher substrate temperatures, changes in temperature have little effect on the evaporation pattern of the nanodroplets. In the last, the evaporation effect of TiO2 nanodroplets is stronger than that of SiO2 nanodroplets at 35 degrees C and 50 degrees C. Overall, this paper provides reliable and practical experimental data and a new direction for enhancing the droplet evaporation process to facilitate the application of hydrophilic nanoparticles.