Concentrated polymerized cationic surfactant phases

Polymerizable surfactants (surfmers) 11-(methacryloyloxy)undecyltrimethylammonium bromide (A), dodecyl(11-(methacryloyloxy)undecyl)dimethylammonium bromide (B), 11-(acryloyloxy)undecyltrimethylammonium bromide (C), and dodecyl(11-(acryloyloxy)undecyl)dimethylammonium bromide (D) have been synthesized and characterized. Mixed micelles of A + B and C + D systems were polymerized by a thermal free-radical water-soluble initiator, to yield transparent solutions that remained stable for months. Copolymerization was followed by NMR, which was consistent with essentially 100% conversion. Lamellar mesophases (80% mass) were prepared by concentration of the polymerized micelles from dilute micellar systems. The mesophases were prealigned in a strong magnetic field prior to small-angle X-ray scattering (SAXS) and polarizing light microscopy studies. Detailed analysis of the SAXS data was consistent with stabilization of lamellar structures, comprising similar-sized internal domains, independent of the mixture compositions or surfactant type studied here. Hence, it is possible to synthesize polymerized liquid crystalline lamellar phases from such well-defined surfmer blends.