Sharon Glotzer


A177 NCRC, Building 10

T: (734) 615-6296





Effect of nanometer scale structure on interfacial energy

Natural surfaces are often structured with nanometre-scale domains, yet a framework pro- viding a quantitative understanding of how nanostructure affects interfacial energy is lacking. Conventional continuum thermodynamics treats interfacial energy solely as a function of average composition, ignoring structure. Here we show that, when a surface has domains commensurate in size with solvent molecules, the interfacial energy is determined not only by its average composition but also by a structural component that causes the interfacial energy to deviate from the continuum prediction by a substantial amount, as much as 20% in our system.

By contrasting surfaces coated with either molecular (5 nm), we find that whereas the latter surfaces have the expected linear dependence of interfacial energy on surface composition, the former show a markedly different non-monotonic trend. Molecular dynamics simulations show how the organization of the solvent molecules at the interface is controlled by the nanostructured surface, which in turn appreciably modifies the interfacial energy.

J.J. Kuna, K. Voïtchovsky, C. Singh, H. Jiang, S. Mwenifumbo, P. K. Ghorai, M. M. Stevens, S. C. Glotzer and F. Stellacci, The effect of nanometre-scale structure on interfacial energy, Nature Materials (2009).