Separation of water–oil mixture on poly methyl methacrylate surface using TiO2 nanoparticles via molecular dynamics simulation

The current work investigates the separation of water–oil mixture on amorphous poly methyl methacrylate (PMMA) surface in the absence and presence of Anatase and Rutile titanium dioxide nanoparticles using molecular dynamics simulation. The presence of nano domains with positive and negative charges on PMMA surface causes the water molecules to form water clusters of various sizes. Water clusters can slide on the PMMA surface which leads to the formation of larger clusters and in continues formation of large clusters was the reason of separation water–oil mixture. In the presence of Anatase and Rutile nanoparticles, accumulation of water molecules around the particles leads to formation of larger water clusters and improves the separation of water–oil mixture. Anatase nanoparticle acts faster than Rutile nanoparticle in the adsorption of water molecules, while Rutile nanoparticle forms larger clusters and is more successful in adsorbing water molecules from the water–oil mixture. The orientation and the order parameter of water molecules in different layers from PMMA surface and around the Anatase and Rutile nanoparticles are investigated as well.