Surfaces, Nanoparticles, and Foams

Abstract

A surface is just the interface between a solid (or liquid) and a gas or vacuum. In general, the surface of a material, or any interface between materials, is a region of excess energy relative to the bulk or matrix. To maintain the lowest total energy for the system, the configuration of the surface adapts itself to minimize this excess energy. Impurities or dopants that lower the surface energy tend to concentrate in the surface. Similarly, such defects move to the interface if by segregating there they lower the overall energy of the system even if it raises the interfacial energy. The surface tends to orient parallel to certain crystallographic planes that have a lower energy.