Swelling Poly(Ionic Liquid)s:Synthesis And Application In Catalysis And Oil/water Seperation

Poly(ionic liquid)s(PILs) refer to a subclass of polyelectrolytes which carry an ionic liquid(IL)species in the repeating monomer units.PILs possess the unique features of structure variability that originated from IL monomers with different anions and cations.The design and synthesis of PILs with special characteristics are important.In this work,the swelling PILs were synthesized and applied as highly-efficient heterogeneous catalysts in the conversion of ethylene carbonate(EC)and super hydrophilic materials in oil/water separation.The main results were obtained as follows:1.Swelling Poly(Ionic Liquid)s: Synthesis and Application as Quasi-Homogeneous Catalysts in the Conversion of Ethylene CarbonateA kind of swelling PILs was prepared by direct radical copolymerization of N-vinylimidazolium ionic liquids and sodium acrylate with 2,2-azobisisobutyronitrile(AIBN)as the initiator and divinylbenzene(DVB)as the cosslinker.The effect of crosslinking density,chain length of 3-substituents and solvent parameters on the swelling ability of PILs were studied.The unique swelling ability of PILs in EC prompted the nonporous heterogeneous catalysts to contact with substrates sufficiently,which enhanced the catalytic activities of PILs similarly to the homogeneous ionic liquids.Under the optimal reaction conditions,the product 3-phenyl-2-oxazolidinone was obtained with a yield of 96 %.The swelling ability of PILs may open an avenue for designing quasi-homogeneous catalysts with high catalytic activity.2.Water-Enriched Poly(Ionic Liquid)s: Highly-Efficient Microreactors for the Hydrolysis of Ethylene CarbonateA kind of PIL catalysts with swelling ability and water enrichment ability in water/EC mixed substrates were designed and synthesized via one step direct radical copolymerization of N-vinylimidazolium ionic liquids,sodium acrylate and the crosslinkers.The effect of 3-substituent groups and crosslinkers on the swelling ability and water enrichment ability of PILs in water and EC was studied.The water enrichment ability of PILs was positively related with the hydrophilicity of 3-substituents on imidazoliums and the crosslinkers,and water could be absorbed inside quantitatively.These PIL catalysts could enrich optimal ratio of water to EC inside and act as highly-efficient microreactors for the catalytic hydrolysis of EC.Under the optimal reaction conditions,the ethylene glycol yield of 98 % and selectivity of above 99 % were obtained.The water enrichment ability of PIL microreactors was helpful for the decrease of water amount and the increase of the catalytic efficiency.3.Swelling Poly(Ionic Liquid)Networks Surppoted by Three-Dimension Stainless Steel Mesh for Highly-Efficient Oil-Water SeparationA simple method was developed for the preparation of stainless steel mesh supported PIL membrane via one step photopolymerization of ionic liquids with acrylic acid in the three-dimension stainless steel mesh network.Due to the combination of superhydrophilic PIL networks and high-strength mesh,the supported PIL membrane was superhydrophilic-underwater superoleophobic and mechanically stable.When applied in the separation of different oil/water mixtures,the separation efficiency of the membrane was above 99.9 %.Additionally,the supported PIL membrane possessed excellent recycle stability and chemical durability under harsh conditions such as strong acid,alkaline solutions and high salinity water.