Investigation of contribution of the intermolecular potential attraction term in surface tension of refrigerant fluids

Theoretical prediction of thermophysical properties of refrigerant fluids using different intermolecular potential models is an attractive challenge in condensed matter physics. For this purpose, in this work, both refrigerant fluids including pure and binary mixtures are considered and their surface tension ($\gamma$) has been theoretically calculated. To obtain the surface tension of refrigerant fluids, three potential models are proposed. The potentials have the same repulsive parts and different attractive terms. The Ornstein-Zernike (OZ) integral equation by the hypernetted chain (HNC) closure is employed to find the pair correlation functions. The OZ equation is numerically solved by expansion of the correlation functions and HC closure in terms of angular functions in Fourier space. After obtaining the radial distribution function for any potential, the surface tension has been computed. The surface tension of each refrigerant fluid is calculated by three potential models. Our obtained theoretical results are compared with the experimental available data. The findings show that for each refrigerant fluid, one of the potential models show better agreement in comparing with experimental results. It means that the attractive term is one of the influencing factors in predicting the surface tension of refrigerant fluids. For pure refrigerant fluids, the best results obtained for R32 with ADD$\sim ░\%0.9$. The best result is obtained for the mixture of R32+R1234yf with ADD$\sim ░\%1.2$.