Solid–Liquid Interface Temperature Measurement of Evaporating Droplet Using Thermoresponsive Polymer Aqueous Solution

Applied Sciences

卷:11

ChangKyoung Choi¹  DaeYun Kim²  HyungJu Lee³  SeongHyuk Lee³  ChanHo Jeong³ 

[1] Mechanical Engineering-Engineering Mechanics, Michigan Technological University, Houghton, MI 49931, USA;

[2] Research Institute, Golden Engineering Co. Ltd., Seoul 05836, Korea;

[3] School of Mechanical Engineering, Chung-Ang University, Seoul 06974, Korea;

关键词: evaporation;    surface plasmon resonance imaging (SPRi);    thermoresponsive polymer;    interfacial region;    Poly(N-isopropylacrylamide) (pNIPAM);   

DOI  :  10.3390/app11083379

来源: DOAJ

【 摘 要 】

The present study aims to measure the solid–liquid interface temperature of an evaporating droplet on a heated surface using a thermoresponsive polymer. Poly(N-isopropylacrylamide) (pNIPAM) was used owing to its sensitive optical and mechanical properties to the temperature. We also measured the refractive index variation of the pNIPAM solution by using the surface plasmon resonance imaging (SPRi). In particular, the present study proposed a new method to measure the solid–liquid interface temperature using the correlation among reflectance, refractive index, and temperature. It was found that the reflectance of a pNIPAM solution decreased after the droplet deposition. The solid–liquid interface temperature, estimated from the reflectance, showed a lower value at the center of the droplet, and it gradually increased along the radial direction. The lowest temperature at the contact line region is present because of the maximum evaporative cooling. Moreover, the solid–liquid interface temperature deviation increased with the surface temperature, which means solid–liquid interface temperature should be considered at high temperature to predict the evaporation flux of the droplet accurately.

【 授权许可】

Unknown