A Study of the Velocity Field during Evaporation of Sessile Water and Water/Ethanol Drops

作     者：John R.E.Christy Khellil Sefiane Euan Munro 

作者机构：School of Engineering University of Edinburgh 

出 版 物：《Journal of Bionic Engineering》 (仿生工程学报（英文版）)

年 卷 期：2010年第7卷第4期

页      面：321-328页

核心收录：

学科分类：081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 081701[工学-化学工程] 

主　　题：evaporation sessile drop velocimetry particle deposition μPIV 

摘      要：Many studies have investigated evaporation of sessile drops in an attempt to understand the effect of wetting on theevaporation *** interest has also increased in the deposition of particles from such drops,with evaporative massflux being deemed to be responsible for ring-like deposits,and counteraction of the mass flux by Marangoni convection explainingmore uniform deposition *** of such deposition processes is important in biological applications,such as the Litos test-system endorsed by the Russian Ministry of Health for diagnosis of urolithiasis and the evaporation ofcolloidal drops for depositing and organizing proteins and *** most cases where deposition from evaporating drops hasbeen studied,velocity information is inferred from the final deposition pattern or from mathematical modeling based on simplifiedmodels of the physics of the evaporation *** this study we have directly measured the flow velocities in the baseof sessile drops,using micro particle image velocimetry,viewing the drop from below,through the cover *** water drops,a radial pattern of flow was observed with a maximum velocity close to but not at the pinned outer *** ‘azeotropic’ethanol/water mixtures,the velocity field is more chaotic to begin with,passing through a phase involving three or four recirculationcells and finally having the same radial pattern as for water drops.