Controllable Synthesis And Application Of COF And Their Composite Materials

Covalent organic frameworks(COF)are crystalline porous organic frameworks which composed of two or more organic molecules through covalent bond.The COF material has high specific surface area,low density,controllable pore size and good stability,therefore,it has great application value in the fields of energy storage,gas adsorption,ion transmission and catalysis.In addition,the COF material can also be combined with other materials to form the multifunctional composite material,which will expand its application in catalysis and photoelectric materials.In order to further expand the application of COF and its composites,we need controllable synthesis of COF and its composites.At present,the control synthesis of COF material and its composites are still in the exploratory stage.In this paper,we use the imine COF materials as the the research object to explore the controllable synthesis of COF and its composites.The correlatio nal researches are carried out as the following three aspects:(1)We synthesized mo nod isperse COF materials with controllable size and morphology by two steps which based on spincrossover.TAPB-DMTP-COF is selected as the research object,first,the formation of amorphous polymer in the first step is controlled by controlling the amount of acid.Second,we successfully synthesized the crystal material with controllable size and the same structure as traditional synthesis by controlling the amount of acid,water,temperature and concentration.At last,the COF spheres of different sizes were studied by different characterization methods.(2)The gold nanoparticles were encapsulated into COF materials by the controllable synthesis of COF materials,and we synthesized the Au@COF composites with different morphology and size.We also explored the role of COF in catalytic reaction through the model catalytic reaction.The gold nanoparticles were encapsulated into COF materials through the modification by PVP.The catalytic reduction of 4-nitrophenol was used as a model to explore the role of COF in catalytic reaction by comparing the catalytic properties of different morphologies and sizes.(3)The nano particle/COF composites which shell can be controlled were synthesized through the proper modification of nanoparticles.The nanoparticles with different sizes and morphology were modificated by amino and PVP,in which,PVP modification can improve the stability od nanoparticles in the solvent,and the amino modification can guide the growth of imine COF on the surface of the nanoparticles.The nano particle/COF composites which shell can be controlled will be synthesized by this method.Meanwhile,we also found that this method is universal for general nanoparticles.Finally,the Fe3O4@SiO2@COF composite was selected to explore its application in dye adsorption and separation.