UC Irvine

Thread-like chains of flexible polymers that adsorb to a solid surface assume a flat ‘pancake’ conformation1 when the surface coverage is low and are only able to diffuse in two dimensions because so many segments are adsorbed. Here we show that the centre-of-mass diffusion coefficient of the polymer chain, measured at dilute coverage to ensure minimal chain–chain interaction, has a strong power-law dependence on the degree of polymerization. This nonlinear dependence of polymer diffusion on a solid surface contrasts with the linear dependence observed on a fluid membrane2.