Ageing Effects in Polymer Surfactant Films

We have recently reported a remarkably rich range of surface segregation and self-organisation behaviour for surfactants and plasticisers in PVA film. These experiments are relevant to the performance of barrier films used to encapsulate surfactants, but in order to understand the ageing effects we would need to processes that would be extremely slow at room temperature. Very recent AFM measurements clearly show local reorganisation of surfactants on PVA film surface, but cannot identify if there is also long range diffusion that would be most relevant to ageing behaviour in these materials. We propose to use NR to study the influence of annealing on spin-cast films to understand how the long-term ageing is governed by long-range migration in PVA films.