Effect of coating organic film on dropwise condensation in microgrooves with nanostructure surface

The Standard photolithography and wet etching technology were applied to prepare the hydrophobic of microgrooves surface on copper plate. The organic STA film were coating on microgrooves surface to promote the dropwise condensation. The experimental data show that the STA coated microgrooves with nanostructure surface show a better performance of hydrophobicity and a larger apparent contact angle. The STA coated microgrooves with nanostructure surface shows a better the heat transfer performance than the microgrooves surface with nanostructures. An increase of the droplet departure diameter and a lower departure frequency, for a larger contact angle hystersis on the microgrooves surface during the DWC process, also results in a decrease in the heat transfer performance of microgrooves nanostructure surface without STA.