Polymer-grafting Of MOF Nanoparticles By UV-induced Photopolymerization And Preparation Of MOF/polymer Nanofibers By Electrospinning

With the hope of integrating their respective advantages,combining MOF materials with polymers to prepare MOF/polymer composites has recently attracted great attention from both the fields of MOF and polymer materials.However,the biggest challenge in the preparation of MOF/polymer composite materials is the poor chemical affinity between the MOF and polymeric matrix.Due to such incompatability,the MOF particles dispersed in the polymer materials are often in the agglomerated state.Furthermore,there are microgaps or voids of different sizes between the surface of the MOF particles and the polymeric matrix.These sitituations affectthe performance of such composites during applications.In this thesis,based on the idea of grafting MOF nanoparticles with polymer to improve their affinity with specific polymer matrix materials,we have developed a simple and green method to graft MOF nanoparticles with various kinds of polymers.Then,we established a simple and versatile method for preparing MOF/polymer composite nanofibers.Finally,the application of this kind of composite materials in degradation of one simulant of neurotoxic agents was explored.In the first part of this thesis,a former method was exploited and improved to graft the surface of MOF nanoparticles with high-density polymeric chains by UV light-induced free radical polymerizationleading to several kinds of polymer grafted MOF nanoparticles.The results show that the polymer grafting process does not affect the original crystal structure of the MOF nanoparticles.The weight average molecular weight of the grafted polymer can reach as high as 500,000,and the mass fraction of the grafted polymer on each MOF nanoparticle can reach 27.8%.Furthermore,the hydrophilicity or hydrophobicity of the polymer grafted MOF nanoparticles can be conveniently tuned by properly choosing the grafted polymers.In the second part of this thesis,the polymer gtafted MOF nanoparticles were dispersed into the bulk materials of corresponding polymers and processed by electrospinning into MOF/polymer composite nanofibers with tunnable material properties and functionalities.Througth charactaertaions of the as-prepared nanofibers indicate that the MOF nanoparticles are homogeneously dispersed inside the fiberic matrix with diminished aggregation and there is no gap or voids between the MOF surface and the polymeric matrix.By controlling the electrospinning conditions,composite fibers with various diameters,loading content of MOFs were prepared.Finally,to demonstrate their potential applications,one of such composite nanofibers containing Ui O-66-NH₂ was used to catalytically degrade dimethyl p-nitrophenyl phosphate(DMNP),a simulant of nerve agent.The half-life was 2.6 min at 40?,and the degradation rate reached 89.3%during 60 min,suggesting effective dregation.These MOF based composite nanofibers can be processed into pratical fabics or devices for pratical applications.