Swelling Poly(Ionic Liquid)s:Synthesis And Application As Catalysts And Absorbents

Swelling poly（ionic liquid）s（PILs）are widely applied in liquid crystal materials,stimulus-responsive materials,gas adsorption/separation,catalysis,water treatment,due to its outstanding properties,such as good thermostability,low flammability,negligible vapor pressure and perfect designability.As catalysts,PILs with good swelling ability will form a qusi-homogeneous system in the substrate,demonstrating a 3-D network structure.In this way,the disadvantages,that heterogeneous catalysts whose active sites are plagued by insufficient contact with reactant and homogeneous catalysts which are hard to separate from reaction system,can be overcome at the same time.As absorbents,swelling PILs show excellent adsorption capacity and broad adaptability.This dissertation focuses on synthesizing swelling PILs with good performance in catalysis and adsorption,finding the connection between swelling ability and catalytic activity and adsorption capacity,mainly including three chapters:1.A concise introduction of researching advances of swelling PILs.2.A series of PILs with swelling ability in ethylene carbonate（EC）has been synthesized through free radical copolymerization of N-vinylimidazolium ionic liquid monomers with divinylbenzene.The structure,morphology and swelling property of the PILs were charicreized by ¹³C MAS NMR,FT-IR and SEM.Cyro-SEM showed that the PILs demonstrate a 3D network structure in swelling state which might promote mass transfer and dispersion of active sites.The PILs were utilized in the reaction of 2-（phenylamino）ethanol and EC and exhibited even better catalytic performance than homogeneous catalyst 1-butyl-3-methyl-imidazolium acetate（BmimOAc）.This superior catalytic activity is strongly related to the swelling property and selective absorption behavior of PILs.The absorption behavior was investigated by ¹H NMR analysis of mole ratio of reactants to product inside and outside of PILs in the reaction mixture.It was found that the PILs could enrich reactants and eject products which could accelerate the reaction.3.A series of PILs with swelling ability in water has been synthesized and thoroughly characterized.The PILs were utilized to get rid of anionic dyes（orange II,methyl blue,amaranth）from their aqeous solution.The results indicated a positive correlation between swelling ability and adsorption capacity.All adsorption process fitted well in Pseudo-second-order and Langmuir model.And the maximum adsorption capacity for orange II,methyl blue and amaranth at 25 ^oC were 1512.2,1909.2 and1314.1 mg/g respectively.The high adsorption capacity was attributed to the good swelling ability.