Regimes of water droplet evaporation on copper substrates

Abstract

Distilled water droplet evaporation has been studied on copper substrate surfaces with different degrees of roughness. Data on variations in the contact diameter have been employed to distinguish between the regimes of distilled water droplet spreading over the copper surfaces that proceed after the viscous regime. For each isolated regime, the duration has been determined as a fraction of the total evaporation time and the main physical processes have been described. Variations in contact angles have been analyzed as depending on copper surface temperature. It has been established that, as the substrate temperature is elevated, wetting becomes better, while the adhesion work remains almost unchanged, thereby indicating the absence of chemical and structural transformations at the liquid–substrate interface.