加热板液滴蒸发的理论分析及实验研究

Theoretical analysis and experimental study on droplet evaporation of heating plate

中文关键词: 接触角，摩擦力，黏滑现象，表面自由能

英文关键词: contact angle, friction, stick-slip phenomenon, surface free energy

中文摘要:

      液滴蒸发是由气-液浓度差驱动的一种常见而复杂的扩散现象。通过实验与理论相结合对去离子水在玻璃表面和有机硅油表面的蒸发特性进行研究，测量了液滴接触角和接触直径随时间的动态演变过程。结果发现：玻璃表面的液滴蒸发为典型的定底半径模式和混合模式；而液滴在有机硅油表面较为特殊，除了定底半径模式和混合模式还有周期性的粘滑模式。出现粘滑现象是由于实际表面的非光滑性，三相接触线存在摩擦力。当摩擦力最大时，接触角继续减小，三相接触线的力难以平衡，液滴接触角突增，三相接触线收缩。

英文摘要:

      Droplet evaporation is a complex diffusion phenomenon driven by gas-liquid concentration difference. The evaporation of deionized water on organic silicon oil and glass surfaces was experimentally and theoreti-cally studied. The dynamic evolution of the contact angle and radius was measured. The result show that the evaporation of droplets on glass surface is a typical constant contact radius mode and mixed mode, while droplets on the surface of organic silicone oil are relatively special. Besides constant contact radius mode and mixed mode, there are periodic stick-slip mode. The stick-slip phenomenon is due to the non-smoothness of the actual surface and the existence of friction in the three-phase contact line. When the friction force is maximum and the contact angle continues to decrease, it is difficult for the force of the three-phase contact line to balance. the contact angle of droplets suddenly increases, and the three-phase contact line contract.