This paper uses electrolyte MIVM (eMIVM) and electrolyte NRTL model (eNRTL) to calculate the osmotic coefficient of the two-component ionic surfactant system containing sodium and chlorine respectively

and compares the calculation results of the two models. Through comparison

it is found that eMIVM has certain advantages over eNRTL in both the sodium and chlorine systems. The fitting deviations of eMIVM and eNRTL in the sodium-containing system were 0.0230 and 0.0420 respectively

and the relative errors of fitting were 2.88% and 4.98% respectively. In the chlorinecontaining system

the fitting deviations was 0.0594 and 0.0606

and the fitting relative errors was 13.19% and 13.95%

respectively. At the same time

the osmotic pressure of the solutions was correlated with the calculation of osmotic coefficient in this paper. It can be seen that in some sodium-based systems

the osmotic pressure calculated by eMIVM is closer to the experimental values

and the calculated deviations is smaller than that of eNRTL

which is more in line with the actual application situation. In addition

in some systems containing sodium

eNRTL shows an opposite fitting trend. This may be because eMIVM has a more reliable statistical thermodynamic basis compared with eNRTL

and can simultaneously describe the contribution of molecular interaction (enthalpy) and the number of microscopic states of molecular configuration (entropy) to excess Gibbs energy. This indicates that eMIVM can be applied to the ionic surfactant system

further expanding the applicability of this model.