不同变质程度煤表面动态行为与临界表面张力的研究

摘要

为研究不同变质程度煤表面动态行为和临界表面张力,利用悬滴法恒温27 ℃测试不同浓度下的烷基糖苷( APG)溶液表面张力,以及利用躺滴法动态连续跟踪测量模式研究不同浓度下的APG溶液在煤表面接触角随时间的变化情况. 研究结果表明:水在煤表面形成接触角较大,且接触角变化不明显;随着APG溶液浓度的增大,溶液在煤表面形成的接触角变小,同时接触角的变化幅度也在增大,当APG溶液浓度超过临界胶束浓度时,接触角进一步减小,但变化幅度减小;接触角余弦值与临界表面张力的相关性显著,且呈负相关关系;随着煤样变质程度的提高,临界表面张力先减小后增大.%In order to study the dynamic behavior and critical surface tension of coal with different metamorphic grades, the pendant drop method was used to test the surface tension of alkyl glucoside ( APG ) solution in different concentrations at the constant temperature of 27 ℃, and the dynamic continuous tracking measurement mode of the sessile drop method was used to study the change of the surface contact angle of APG solution in different concentrations with time. The results showed that the contact angle of water on coal surface was relative large, but its change was not obvious;with the increase of APG concentration, the contact angle of APG on coal surface decreased while the change magnitude of the contact angle increased, when APG concentration exceeded the critical micelle concentration, the contact angle further reduced, so did its change magnitude; the cosine value of the contact angle was significantly correlated with the critical surface tension, they were in a negative correlation;with the increase of the metamorphic grade of coal, the critical surface tension first decreased and then increased.