Effect of porosity and temperature on viscosity and diffusivity of benzene liquid containing nanobubble with molecular dynamics

Abstract

Introduction of nanobubble (NB) into liquid can significantly affect the transport properties such as viscosity and diffusivity, being important in the design and optimization of many liquid-related industrial processes. The present paper reports the atomistic insights into influence of porosity (volume fraction of NBs in solution) and temperature on viscosity and self-diffusion coefficient in benzene liquid containing NBs by using molecular dynamics (MD) simulation with the COMPASS force field. We make molecular modeling of NB-containing benzene liquid using the cubic box with porosities increasing from 0 to 24.6% and conduct a series of MD simulations as increasing temperature from 298 to 343 K. Our simulations reveal that as increasing the porosity the viscosity decreases according to the cubic polynomial while the self-diffusion coefficient increases rapidly. When compared with high polar NB aqueous solutions, although the changing tendencies of transport properties are similar, the changing degrees in benzene liquid are clearly higher, indicating that NB creation has a stronger influence on transport properties of non-polar benzene liquid due to the weaker intermolecular interaction. Meanwhile, as increasing temperature, the viscosity decrease while the self-coefficient increases, both according to the Arrhenius equation. Such temperature dependence is similar to aqueous solution, meaning that temperature affects the transport properties of polar and non-polar liquids alike. This work will contribute to developing NB utilization to practical applications.