PNNL

Abstract

Surfactants are widely used as templates to control the nucleation and growth of nanostructured metal oxides such as titania. To gain insight into the origin of surfactant-titania interactions responsible for polymorph and orientation selection, we simulate the self-assembly of an anionic surfactant monolayer on various low-index titania surfaces and for a range of densities. We characterize the binding in each case and compute the adhesion energies, finding anatase (100) and rutile (110) to be the strongest-binding surfaces. The sodium counterions in the monolayer are found to dominate the adhesion. It is also observed that the assembly is directed predominantly by surface-monolayer electrostatic complementarity.