Separated Organized Polymerization of an Amphiphilic Monomer and Acrylamide in One-Pot Reaction

Abstract

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.

Anisotropic hydrogel based on bilayers: color, strength, toughness, and fatigue resistance

“…It has been elucidated that DGI is homo-polymerized and entrapped in the PAAm network without forming covalent bonds with PAAm and the cross-linker (MBAA). 18 The gel exhibits iridescent multi-colors and is isotropic in the macroscopic scale, similar to the precursor solution. 16,17…”

Multi-functions of hydrogel with bilayer-based lamellar structure

“…In the past decades, Tsujii et al have discovered a micro-scale lamellar structure of a self-assembled surfactant in the aqueous solution which can be fixed in the network structure of hydrogel by polymerization in mixed monomer solution. However, this micro-domain lamellar superstructure in hydrogel plays negligible improvement in the functional hybrid gel material due to the poly-domains of the lamellar phase in macro-scale [24][25][26][27]. Very recently, Gong's group has developed a successful method for formation of macroscopic (integrated microscopic) single-domain lamellar bilayer structure with periodical stacking inside the polymer matrix of the hydrogel [28,29].…”

Supramolecular hydrogels with multi-cylindrical lamellar bilayers: Swelling-induced contraction and anisotropic molecular diffusion

“…Finally, co-current polymerization of DGI and AAm is performed to immobilize the lamellar structure of the polyDGI (PDGI) inside the PAAm network. [17] The PDGI layers and the PAAm network weakly interact through hydrogen bonds to maintain the structural integrity of the gel, which has been confirmed from the absorption peak shift of hydroxyl group (-OH) of DGI and amide group (-CONH2) of AAm observed with infrared spectroscopy. [18] Here, we describe the swelling-induced contraction and quasi one-dimensional diffusion of PDGI/PAAm gels formed into string-like shapes (as opposed to the reported rectangular sheet shape).…”