Vapor-liquid phase equilibrium of n-pentane in quartz nanopores by grand canonical Monte Carlo calculation

•GCMC method was used to study the phase behavior of n-pentane in quartz nanopores.•The relationship between pore size and critical pressure/temperature is quantitatively characterized.•The interaction between slit and fluid is analyzed, and the process of fluid phase transition is explained.•The maximum aperture affects critical temperature of n-pentane is 10 nm, while critical pressure is 30 nm.