毛细管内化学反应驱动的润湿过程实验研究

Experimental study of dynamic wetting driven by chemical reaction in capillaries

毛细管内不相溶油水系统中由于存在化学反应而诱发动态润湿过程。当系统置于水平毛细管中时,界面出现接触角不对称、反应性润湿过程及界面变形,并伴随有Marangoni对流。通过分析反应系统在垂直毛细管、非反应性系统在水平毛细管中的界面特性及对系统界面张力值的测量,发现化学反应产生一种阴离子表面活性剂,使得油水界面张力大幅度下降,而二相的静压力差则是导致接触角不对称的主要原因。

The dynamic wetting was induced by an interracial chemical reaction in an immiscible oil-liquid system in capillaries. When the capillary was put in a horizontal position, the contact angle asymmetry and the reactive wetting cycle leading to large-scale interracial deformation were identified, accompanied with Marangoni convection. By analyzing the interface characteristics of the reaction system in vertical capillaries and the non- reactive system in horizontal capillaries, together with the interracial tension measurements, an in-situ anionic surfactant was produced during the chemical reaction which lowers the interracial tension drastically. And the contact angle asymmetry can be mainly attributed to the hydrostatic pressure difference between the two phases.