醇水混合冷却剂表面张力和接触角的测定

Measurement of Surface Tension and Contact Angle of Alcohol-water Mixed Coolant

喷雾冷却具有散热能力强、冷却工质需求量小等优点,在解决电子器件散热方面具有广阔的应用前景。纯水中添加醇类可以有效提升喷雾冷却性能。为进一步探索醇类添加剂强化喷雾冷却性能的机理,本文开展醇水混合溶液表面张力和接触角的实验测定研究。分别在水中加入不同浓度的乙醇、正丙醇、正丁醇、正戊醇、正己醇、正庚醇和正辛醇等醇类,利用悬滴法探究醇类浓度对溶液的表面张力的影响规律;利用Young-Laplace坐滴法探究醇类浓度对接触角的影响规律。结果表明,水中添加醇类后表面张力降低,且其随醇类溶质浓度的增加而变小,且其下降速率均随浓度的增加越来越慢;添加低醇类添加剂均可降低溶液的接触角,而高醇类接触角随浓度变化没有明显的变化规律。

Spray cooling has the advantages of strong heat dissipation and small cooling quality.It has a broad application prospect in solving the heat dissipation of electronic devices.Experiments have proved that adding alcohol additives in pure water can effectively improve spray cooling performance.In order to further explore the mechanism of enhancing the spray cooling performance of alcohol additives,the experimental study on the surface tension and contact angle of alcohol water mixed solution was carried out.Ethanol,n-propanol,n-butanol,n-pentanol,n-hexanol,n-heptanol and n-octanol and other alcohols were added to the water respectively.The effect of alcohol concentration on the surface tension of the mixed solution was investigated by PDM measurement,and the effect of alcohol concentration on the contact angle of alcohols was investigated by Young-Laplace drop method.The results showed that the surface tension of the mixed solution decreased with the increase of alcohols concentration,and the decrease rate of surface tension decreased with the increase ofconcentration.Adding low alcohol additives can reduce the contact angle of the solution,while the contact angle of high alcohol has no obvious change rule with the concentration change.