Quantitative Analysis of the Dispersion Interaction of Liquids with the Surface of Gamma-Irradiated PTFE

The Hamaker constants are calculated for the PTFE/PTFE, PTFE/tetradecane, and PTFE/water (PTFE is polytetrafluoroethylene) systems using various dielectric models. Selection of the dielectric model significantly affects the absolute values of the Hamaker constants while it has virtually no effect on their relative changes depending on the density and dielectric increment of PTFE. The total calculated changes in the work of adhesion due to van der Waals interactions, taking into account changes in density and dielectric increment in gamma-irradiated PTFE, do not exceed 11% for all dielectric models used. It is concluded that changes in surface energy upon the irradiation of PTFE cannot be explained solely by an increase in the contribution of the van der Waals interaction due to polar radiolysis products. It is necessary to consider the electrostatic interaction of stabilized charges with the dipoles of a polar liquid.