Effect of structured surface on contact angle using Sessile Droplet method

Abstract

At the age of energy-crisis, enhancement of boiling heat transfer is the most crucial and advanced investigation field. Effects of surface characteristics, specially, surface wettability on pool boiling is yet to understand. Wetting, the ability of solid surface to reduce surface tension of a liquid in contact, can specify by measuring contact angle. Sessile drop method is a very sensitive process to measure contact angle, mainly used for evaluating, comparing and monitoring test surfaces. In this experimentation, a set of copper surfaces are roughened by emery grit size of 600, 1000, 1500 and 2000. Data on surface roughness (generated by AFM and FEG-SEM) and on dynamic contact angle (by macroscopic contact angle (CA) meter) are used to find relation between them. De-ionized water is used as working fluid to protect submerged secondary heater. In this experimentation, it is observed that advancing contact angle grows for surface roughened with higher emery grit-size.