Phase Behavior and Microstructure of Polymerizable Microemulsions

The phase behavior of polymerizable alkyl methacrylates (C&MA, k = 1,4, and 6) in aqueous solutions containing mixtures of the cationic surfactants dodecyltrimethylammonium bromide (DTAB) and didodecyldimethylammonium bromide (DDAB) is systematically studied. The added degree of freedom afforded by mixing the surfactants allows location of a region in the water-rich cornrr of the phase diagram where a homogeneous microemulsion phase forms for three alkyl methacrylates of differing hydrophobicity. Microstructural studies using small angle neutron scattering (SANS) demonstrate that oil-in-water microemulsions form and show that the shape of the aggregates depends on the DTAB:DDAB ratio and the oil content.