Molecular dynamics simulations on the water diffusion in modified silica membrane with TiO2

Abstract

Today, the use of modified silica membranes for the osmosis process has received attention. Titanium dioxide (TiO2) has a significant application in increasing the efficiency of osmotic membranes due to its hydrophilic, antibacterial, and nontoxic properties. A molecular dynamics (MD) simulations approach is applied to theoretical insights into the effect of concentration of TiO2 in silica membrane on the water molecules diffusion. The diffusion coefficient of water in modified forward osmosis silica membranes with 10−6, 10−4, 10−2, 0, 1, and 100-mole ratios of TiO2 has been calculated from the mean square displacement (MSD) of H2O molecules and obtained (0.015,1.952,2.570,2.810,0.078and0.086)×10−9m2s, respectively. The results of our simulations are in excellent agreement with the experimental results and also can be compared to the diffusion coefficient of water in Polyamide (PA) membrane as one of the most important membranes at reverse osmosis for water desalination about 0.600×10−9m2s.

Keywords

• Silica membrane
• TiO2
• Water diffusion
• Molecular dynamics simulation