Physical and chemical insights into molecular adsorption of copolymer's monomers on Rutile surface

The adsorption of triblock copolymer's moieties such as DME, 1,2-DME, and 1,2-DMP on a Rutile surface has been studied by DFT. The insights into their adsorption mechanism have been investigated by analyzing various physical and chemical properties such as the adsorption energies, the structural properties, difference of charge density, density of state, bond overlap population, and the atomic partial charge. Dispersion interaction plays a major role on the absorption energy in 1,2-DME, and the upward bridging oxygen configurations of DME and 1,2-DMP; whilst electrostatic and polarization energies are insignificant. A new Ob-Ti bond has been formed from the overlap of lone-pair electrons between orbital O 2p and Ti 3d in downward bridging oxygen configurations of DME and 1,2-DMP, which results in a significantly larger adsorption energies compared with other configurations. The molecular torsion is considered as a barrier that prevent Ob-down of 1,2-DME to create the bond with Ti.