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

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-ADSA mode by ADSA software.The surface tension of substrates were calculated by new theoretical equation.The results 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.