Micro-flow induced peculiar surface profile of film from dried droplet of water-Poly (ethylene oxide) solution
We report a pcculiar surface ofpoly(ethylene oxide) (PEO) film from droplet ofwater-PEO solution dried at heating substrate.The drying process contains two stages.The contact line is pinned initially.When substrate temperature reaches 60 ℃,it starts to recede and continues to leave a film.The resulted film contains an edge-ring and middle-step surface profile.The rheological properties of PEO solution were studied.We found that capillary flow is dominant in the first drying stage and Marangoni flow appears because concentration gradient induced strong Marangoni effect and high temperature induced sharply decrease of viscous stress resulted in the contact line receding in the later drying stage.We confirm that the ringlike deposit is formed by outward capillary flow and the step in the middle is formed by Marangoni flow which carries solute to the inner,and these flows compete with the viscous force.
Poly(ethylene oxide) Droplet Micro-flow Surface profile
Hu Yinchun Zhou Qiong Dong Cuicui Cui Lishan
Department of Material Science and Engineering, College of Science, China University of Petroleum(Beijing), Beijing, China
国际会议
广州
英文
358-361
2012-11-16（万方平台首次上网日期，不代表论文的发表时间）