| Many solvents can be gelated by some compounds of low molecular weight at low concentrations (typically < 1 w t %) and form thermally-reversible viscoelastic liquidlike or solidlike materials that are called molecular gels or organogels. Such low molecular-weight compounds are called "gelator". Gel self-assembles into a well order and three-dimensional construction in the solvent by the force of non-covalence, such as π-πstacking, hydrogen bond, hydrophobic, van der waals force etc. By design of gelator, 4, 4′-bis(stearolamino) diphenyl methae (BSDM) has been synthesized. BSDM can aggregate and self-assembly in polymerizable organic solvents. As the result, the molecular gels of polymerizable solvents,such as styrene,butyl acrylate,methyl methacrylate and 2-hydroxyethyl methacrylate can be formed by BSDM aggregates. The temperature of gel/sol transition(TGS) was related to the concentration of BSDM. Increased mass fraction of BSDM resulted in a increase of hydrogen bonds and π-πstack in the system, which need more energy to destroy. TEM pictures show that BSDM self-assembled into long fibres which diameter is about 50~700 nm by non-covalent interactions in polymerizable solvents. POM pictures show the formation of spherulites undergoing aggregation of self-assembled fibres before and after polymerization of solvents. Shape and diameter of spherulites do not affected basically by polymerization of solvents. Optic microscope pictures show that aggregation of BSDM is dendritic Aggregation of BSDM change with temperature. With the increase of temperature, dendritic structure of BSDM is dissolved at TGS. When temperature descend ,dendritic structure of BSDM appear again at lower temperature.
|
PDF Full Text Request