Study of droplet dynamics and condensation heat transfer on superhydrophobic copper surface

Abstract

Superhydrophobic surface for dropwise condensation is prepared using hotplate solution immersion method on copper substrate. The preprocessed bare copper plate is immersed in a solution consist of 0.004-0.008 M ethanol (CH3-CH2-OH) and tetradecanoic acid (CH3(CH2)12COOH) then heating the plates in the solution at 30-50?C for 1-6 hours. The contact angle of water droplet on the prepared surface is measured using low bond axisymmetric drop shape analysis, which gives the maximum contact angle of 168? and average value of 166? ?2?. The maximum contact angle is obtained by adjusting the composition of the solution, temperature of the solution and immersion time to 0.006 M, 45?C and 4 hours, respectively. The various superhydrophobic surfaces are prepared by changing constituents of solution, hotplate temperature and processing time, respectively. Further dynamic behavior of water droplet on the prepared surfaces like jumping effect and rolling effect is presented in this work. In addition, experimental work is carried out on the prepared surface for dropwise condensation and the obtained results are com-pared with condensation on bare copper plate produces higher heat transfer coefficient.