Building And Performance Research Of Thermo-sensitive Micelle System Based On Quaternary Ammonium Salt Cationic Surfactant

Construction of new intelligent micelles is a hot field in self-assembly chemistry by the amphiphilic molecules with specific functions and properties. In this paper, we intend to build stable micelle structure by the single and double chain surfactant-water-additives,utilizing multiple weak intermolecular interactions to construct thermosensitive intelligent micelles. The formation process of wormlike micelles, micellar structure transformation and temperature-switchable processes of intelligent mecellar systems will be determined by utilizing rheological measurement, and kinetic parameters for the processes will be obtained. Structure-activity relation between the aggregate structures and the important factors, including molecular structures of surfactants, countra-ion and additives, are to be systemically investigated by combining the kinetic properties with the electron microscopic, conductivity and nuclear magnetism technologies. The micellar formation mechanism, the micro-structure of the intelligent micelles, the rule of micellar structure transformation induced by temperature, and the effects of additives on the structure formation will be explored. These research works can reveal the interaction mechanism between the molecules in the process of intelligent micelle formation, and the synergistic interactions of various non-covalent forces from the point of view at molecular level, establish the new supramolecular structures and widen the type of and the function of assembly and deepen the understanding about the basic issues and related laws in the supramolecular chemistry and self-assembly field, which is quite useful.As a part of the project supported by National Natural Science Foundation(No.21073081 and No.21473084), the present work consists following parts:I. The rheological behavior of single quaternary ammonium salt cationic surfactant aqueous solution in different temperatureThe rheological properties of single quaternary ammonium salt cationic surfactant cetyltrimethyl ammonium salicylic acid(C16TASal) aqueous solution in different percentage composition and temperature have been discussed. The solution of 3%C16TASal showed high viscosity similar to gel, but long micelle was not observed in thesystem by freeze etching electron microscope scanning(FF-TEM). Single crystal diffraction experiment demonstrate the presence of hydrogen bonding of intermolecular and intramolecular, so short micelles interact to form network structure through hydrogen bonding. But the temperature of system slightly influence to the viscoelastic of system,so the structure of micelles remain unchanged in investigated temperature range.II. The viscoelastic behavior of mixed aqueous solution of single quaternary ammonium salt cationic surfactant and organic acid in different temperatureViscoelastic behavior of the traditional quaternary ammonium salt cationic surfactant cetyltrimethyl ammonium bromide(CTAB) and organic acids3-methylbenzoic acid mixed aqueous solution in different concentration ratio and temperature have been researched. Rheological technology and Cryo-TEM showed that the aggregation produce the transformation of spherical micelles to wormlike micelles, to rod micelles, eventually to vesicles simultaneously. Furthermore, these samples have the transformation of spherical-to-wormlike micelles or vesicle-to-micelle when the solution was heated.III. The rheological behavior of single quaternary ammonium salt cationic surfactant and anionic surfactant mixed aqueous solution in different temperatureViscoelastic behavior of mixed aqueous solution of single quaternary ammonium salt cationic surfactants 3-alkoxy-2-hydroxypropyl trimethyl ammonium bromide(C14HTAB) and anionic surfactant sodium caprylate(SO) have been investigated. The influence of concentration proportion on the viscoelastic of system is tremendous and the environment temperature and cationic surfactant chain length can also adjust the viscoelastic of system.IV. The research of micelle behavior of single quaternary ammonium salt cationic surfactant and nonionic surfactant mixed aqueous solution in different temperatureExplored the rheological properties of double chain quaternary ammonium salt cationic surfactants 2-hydroxypropyl-1,3-tetradecyl dimethyl ammonium chloride and nonionic surfactant polyoxyethylene laurel ether mixed aqueous solution with the change of concentration and temperature. In certain concentration, the viscosity of the systemappears a maximum with the increase of temperature.