Molecular simulation study of penetrant gas transport properties into the pure and nanosized silica particles filled polysulfone membranes

Elucidation on the Effect of Operating Temperature to the Transport Properties of Polymeric Membrane Using Molecular Simulation Tool

“…The findings are consistent with various published reports on the diffusivity of gas molecules through polysulfone membranes [16,[38][39][40]. It has been reported that oxygen is the species that gain most energy and have the energy to execute longest diffusional jump among all penetrants [23].…”

“…The point at which the glassy and rubbery linear correlation meets to form an intercept provides graphical representation of Tg The intersected point at 454.94 K is Tg obtained from current simulated work. When comparing the obtained T g through this simulation, to literature record of 460.15 K [23], the error is at −1.13%. Thus, it can be said that the proposed methodology is reliable to obtain molecule structures of high accuracy, before applying in subsequent section to study the gas transport properties at varying operating temperatures.…”

“…In current work, the diffusivity of gas penetrants has been determined adopting the means of molecular positioning theory, or more commonly known as the Einstein relationship [18][19][20][21][22][23][24]. In Einstein correlation, he related the self-diffusion coefficient of gas particles i, D i to the mean square displacement (MSD) as a function of observation time, such as that presented in (1), through the assumption of particle random walk [25].…”

“…The embedded adsorption isotherm simulation allows end users to perform a series of grand canonical Monte Carlo ensemble (GCME), in which fugacities of all related components and temperature of the hypothetical system are remained constant. In this simulation work, the gas penetrants have been incorporated within the equilibrated cell adopting the Metropolis methodology since it has been demonstrated in previous published molecular simulation works to be an adequate characterization for system with relatively small sorbates as compared to pore size of the polymeric matrix and inherits low degree of torsion flexibility, which are highly applicable to gas molecules such as O 2 , N 2 , CO 2 and CH 4 [23,26]. The GCME in sorption module has been executed for 100 fugacity steps between 0.00001 to 101.325 kPa in equidistant steps.…”

“…Most simulation techniques are inclined towards determining the condition at infinite dilution and relating it to the solubility coefficient, such as that depicted in (2) [23,[27][28][29].…”