高聚物表面的润湿性实验及表面张力的计算

Experiment of Wettability of High Polymer Surface and Calculation of Surface Tension

采用座滴法研究了去离子水等8种测试液体在聚四氟乙烯等6种低能固体表面上的润湿性,用ADSA滴形分析软件的LB-ADSA模式测量了接触角。以新的润湿性理论计算方法为基础,分别计算了6种固体物质的表面张力。结果表明,采用座滴法研究润湿性及固体的表面张力时,表面张力引起的接触角的变化存在着敏感区与非敏感区,当测试液体的表面张力远大于固体材料的表面张力时,表面张力的变化对接触角的影响敏感,用座滴法所计算的固体表面张力数值具有较好的一致性和准确性,因而可以用表面张力较大的纯净液态水作为计算大多数高聚物表面张力的测试液体。实验所获得的固体表面张力数值均大于相关文献给出的计算值,表明目前常用的几种表面张力近似算法存在着计算数值偏小的问题。

Experiments of wettability with eight liquids such as deionized water on the surface of PTFE and five other solid materials were implemented by sessile drop method, contact angles were measured based on the LB-AD- SA mode by ADSA software. The surface tension of substrates were calculated by new theoretical equation. The resuits show that when wettability and solid surface tension is studied by sessile drop method, there exist sensitive area and insensitive area which have effects on the change of contact angle caused by surface tension. Since when the surface tension of measuring liquid is much larger than that of substrate, the change in the solid surface tension has sensitive effect on the contact angle, and the value of solid surface tension calculated with the new theoretical equation is well consistent and accurate, it is feasible to use large surface tension liquid pure water as the measuring liquid for the calculation of most surface tension of high polymer. The results also suggest that the values of solid surface tension caculated with new method are larger than those reported by relevant literature, which indicates that the values of solid surface tension caculated with existing surface tension calculation methods are smaller.