We have been studying the formation of solid polymer-surfactant films at the air-solution interface formed from cationic surfactants with PEI. We wish to use the highly organised mesostructures formed in the films as hosts for polymerisation of styrenein order to prepare polymer nanostructures which will reinforce our films. Previously polymerisation of monomers in swollen micelles has destroyed the mesophase due to rapid diffusion of surfactant during the reaction. In our films the high viscosity of the hydrogel may prevent rearrangement of the micelles during the reaction. In this experiment we wish to study the effect of surfactant chain length on the incorporation of styrene in the films, and on their structure. Earlier experiments showed surfactants with aromatic headgroups are most effective for styrene incorporation so we will use pyridinium and benzyldimethylammonium surfactants.