Surfactant Segregation in Plasticised PVA

PVA film is widely used as a non-toxic water soluble polymer. This proposal relates to its use in unit dose detergent pouches where plasticised PVA film stores a concentrated mixture of surfactants. We wish to understand the ageing and failure mechanisms of these films and in particular the extent to which small molecules within PVA film can migrate to the surface and modify the surface properties. We propose to use neutron reflectometry to explore the surface properties of model PVA films containing surfactants and/or glycerol plasticisers. Selective deuterium labelling of one or other component will be used to determine surface adsorption from within a PVA film and the influence of these components on a PVA/liquid interface.