Evaporation characteristics of sessile ethanol-water mixture droplets

被引：0

作者：

Jin Y. ^{[1
]}

Shan Y. ^{[1
]}

机构：

[1] School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai

来源：

Huagong Xuebao/CIESC Journal | 2018年 / 69卷 / 07期

关键词：

Ethanol; Evaporation; Mass transfer; Mixing;

D O I：

10.11949/j.issn.0438-1157.20171267

中图分类号：

学科分类号：

摘要：

Droplets evaporation is a common phenomenon. It's necessary to keep studying on the evaporation mechanism of multi component droplets, which can promote the development of related industry and technologies, such as pesticide powder spraying, inkjet printing, industrial coating and rapid cooling technology. Based on silicon and PTFE films, the evaporation of water-ethanol mixed liquid drops are studied by using 10%, 20% and 30% concentrations of ethanol and pure water. The CCD camera is used to record the change of the appearance of sessile droplets. Then evaporation characteristics of mixed droplets are obtained by analyzing the contact angle and contact radius. It can be seen from the experiment that the evaporation time shortens obviously after adding ethanol. The evaporation of mixed droplets on silicon wafers consists of three evaporation stages as similar as pure water. But the evaporation time of the both first and second stages reduced. And there is a sudden increase in angle at second stage in the experiment of 10% and 20%. On the PTFE film, the pure water droplet has only constant contact radius and mix evaporation stage. When the ethanol content increased to 20%, the first stage turns to be the constant contact angle evaporation mode. As the concentration of ethanol increases, the rate of mix stage is mainly raised. Besides, from the angle of rate and capacity of evaporation, it was found that two liquids may evaporate at the same time. But when the concentration of ethanol is high, the ethanol evaporates faster than pure water. For droplets on the silicon, pure ethanol evaporates in the first stage when the concentration reaches 30%. On the surface of PTFE, the concentration threshold of the ethanol is 20%. Therefore, the concentration of ethanol which can change the order of evaporation varies with the kind of surface. In summary, the addition of ethanol will affect the droplet evaporation mode and the total duration. © All Right Reserved.

引用

页码：2908 / 2915

页数：7

共 30 条

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