Synthesis And Property Research Of Ionic Liquid Functionalized Janus Materials

Janus materials with two compositions distinctly compartmentalized onto the same object have received increasing attention. Properties of Janus materials depend on its composition and structure. In this dissertation, Ionic Liquid (IL) and Polymeric Ionic Liquid (PIL) were introduced to the Janus materials for the first time, and the obtained IL or PIL functionalized Janus materials show some unique properties, for instance, good anion responsiveness and excellent catalytic activities and especial separation property, etc. The detailed contents are as below.1. By an acid catalyzed sol-gel process in emulsion, imidazolin-and phenyl-siloxanes self-assemble at the interface of emulsion droplets, and the terminated imidazolin and phenyl spontaneously face towards the external aqueous and the internal oil phases of emulsion respectively. A kind of imidazolin functionalized Janus hollow spheres with a silica shell were obtained after removing the oil phase, where the imidazolin and phenyl are outside and inside the hollow spheres respectively, and the corresponding imidazolin functionalized Janus nanosheets were derived from crushing the Janus hollow spheres. IL functionalized Janus nanosheets were achieved by selectively modifying the 2-imidazolin-1-yl groups with 1-chlorobutane, while the other hydrophobic phenyl-side was preserved. The wettability of IL side on the Janus nanosheets could reversibly transform between hydrophilicity to hydrophobicity through exchanging the anion of IL. As a solid surfactant, the IL functionalized Janus nanosheets could emulsify immiscible Oil-Water two phases and the stability of the emulsions could be controlled by anion exchange of IL.2. Similar to the above, amino-group modified Janus hollow spheres with asymmetric shell were synthesized by a self-organized sol-gel process at an emulsion interface. Janus nanosheets were achieved by crushing the corresponding Janus hollow spheres. Onto the amine-terminated of the Janus nanosheets, an ATRP agent was selectively grafted, and PIL functionalized Janus nanosheets were synthesized through a polymerization of an ionic liquid monomer (ViEtIm+Br-) onto the ATRP agent terminated side of the Janus silica nanosheets. After a simple anion exchange of Br- with PW12O403-, the PW12O403- based PIL Janus nanosheets were derived. The PW12O4O3- based Janus composite nanosheets are amphiphilic and can serve as a solid emulsifier to stabilize a toluene-in-water emulsion. Example dye MO is preferentially absorbed within the PIL layer and degraded by H2O2 in the emulsion, the intermediate products can transfer into the internal toluene oil phase as their hydrophobicity. Higher MO degradation efficiency in was achieved in the emulsion due to the synergistic effect of absorption, degradation and phase transfer.3. A composite core/shell Fe3O4@mSiO2 nanoparticles is synthesized by coating mesoporous silica onto a submicrometer-sized Fe3O4 sphere. Ionic liquid was modified on the external surface of Fe3O4@mSiO2 particles. Then the Fe3O4 core was uncompletely removed by etching with the aim of making a void space inside the SiO2 shell while the magnetism property is kept. Thermal responsive poly (N-Isopropyl acrylamide) (PNIPAM) was grafted on the internal surface of the Janus cages. Finally, the catalytic activator PW12O403- was introduced to the IL group on the external surface of the IL/PNIPAM Janus cages through anion exchange. Example azo dye Sudan IV dissolved in toluene was heterogeneously degraded in aqueous solution with the IL/PNIPAM Janus cages in the presence of H2O2 at room temperature. Through changing temperature of the system, the organic phase and hydrophobic degradation products could be separated from the water due to the thermal responsiveness of PNIPAM after the catalytic reaction.