1A nonionic surfactant, n-dodecyl glyceryl itaconate (DGI), self-assembles into bilayer membranes in water having a spacing distance of sub-micrometer in the presence of small amounts of ionic surfactants, and shows beautiful iridescent color. Ionic surfactants have great effects on this iridescent system. We have interestingly found that the iridescent color changes with time after mixing DGI and ionic surfactants and the color in equilibrium state changes greatly with changing concentration of the ionic surfactants. The time dependent color change results from the transformation of DGI aggregate structure after being mixed with ionic surfactant. It is first found that the iridescent color of this nonionic system can be changed from red to deep blue by altering the concentration of ionic surfactants added even though the total concentration of surfactant is almost constant. Such large blue shift of the iridescent color in equilibrium state cannot be fully explained by the ordinary undulation theory applied so far for this phenomenon. The flat lamellar sheets tend to curve by increasing the concentration of ionic surfactants to form separated onion-like and/or myelin-like structures. These separated structures of lamellar system result in the decrease of spacing distance between bilayer membranes because some vacant spaces necessarily appear among these structures.

It has been first found that separated homopolymerization of an amphiphilic monomer, dodecylglyceryl itaconate (DGI), and acrylamide takes place even in one-pot radical reaction. The DGI molecules form a lamellar liquid crystal of bilayer membranes having the spacing distance of submicrometer and show the iridescent color in the presence of small amount of ionic surfactant. This colored bilayer system can be polymerized together with acrylamide and methylenebis(acrylamide) by photopolymerization to form a hydrogel containing the lamellar structure inside. In this polymerization process, the DGI molecules polymerize alone to form its homopolymer without reacting with any acrylamide and/or methylenebis(acrylamide) molecules. This novel phenomenon has been substantiated by the experimental techniques of SDS-poly(acrylamide) gel electrophoresis, 1 H NMR, and IR spectroscopy. This novel homopolymerization of DGI may be resulted from the preferential bond formation between DGI molecules in their organized molecular assembly and is quite interesting with special reference to the chemical reactions in biological systems. The present reaction system may provide a simplest artificial model for the biological reactions in the complicated organized molecular assembling systems.

A racemic amphiphilic monomer, n‐dodecyl glyceryl itaconate (DGI), forms bilayer membranes in water in the presence of small amount of ionic cosurfactant and shows iridescent color. A chiral DGI, S‐DGI, also shows an iridescent property, but with a rather red shift in the color, which can be ascribed to the increased packing density of the monomer in the bilayer membranes. Chrial DGI has a more compact packing density than racemic one owing to closer distance between the monomer molecules; the conversion rate, however, is slower than that of racemic one when H2O2 is used as an initiator. When the initiator is changed to an amphiphilic one, 4‐(2‐hydroxyethoxy) phenyl‐(2‐hydroxy‐2‐propyl) ketone (Irgacure 2959), the chiral DGI shows even a little faster conversion rate than that of racemic one. The NMR chemical shift results of protons in benzene ring show that the molecules of Irgacure 2959 insert into the bilayer membranes. The molecular weights of the corresponding polymers prove that the initiation by H2O2 is restricted compared to that by Irgacure 2959. It is concluded that the decelerated polymerization behavior of chiral DGI initiated by H2O2 is a result of limited diffusion of the initiator into the lamellar bilayer structures. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4891–4900, 2007

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