Performance enhancement of a diffusion-type solar still: Wettability and flowability of condensation surface

Several studies have been conducted to enhance the production of solar stills. However, studies focusing on the augmentation of condensation are still insufficient compared with those focusing on production improvement by enhancing evaporation. This study evaluates the effect of contact and sliding angles of condensation surfaces, which are criteria for determining wettability and flowability on the production of solar stills. Single-effect diffusion solar still was fabricated, and glass specimens with various wettability properties were prepared as condensation plates of the still to compare the performances. Experiments were performed by changing the condensation plates of the solar still. Meanwhile, the condensation process and droplet forms were observed as a function of wettability. The experimental results showed that the production rate increased by 45% with a decrease in the sliding angle; it also increased as the surface became superhydrophilic or superhydrophobic, but the sliding angle was a better indicator. Therefore, the material to be used for the condensation surface should be selected based on the sliding angle preferentially.

Automated summary

This study evaluates the effect of contact and sliding angles of condensation surfaces on the production of solar stills. The results show that a decrease in the sliding angle and the use of superhydrophilic or superhydrophobic surfaces can increase the production rate. The sliding angle is a better indicator for material selection.