Study On Heteropore Structure And Ionized Pore–wall Structure Of COFs

Covalent organic frameworks(COFs)are porous organic materials which are formed by small organic molecules through covalent bonds.COFs have some outstanding advantages,such as regular channels,well-defined structure,and ?-conjugated frameworks.These advantages have offered COFs materials with superior potentials in various areas,such as gas adsorption separation,heterogeneous catalysis,fluorescence sensing,and optoelectronic materials.The property of the pore is one of the most important properties of COFs.Therefore,how to adjust the performance by tuning the hydrophobicity,acidity,and pore size of the pores is basic to realize the high value-added applications.Accordingly,in this thesis,to find the relationship between the porous structure and the material properties,we tried to synthesize heteropore COF materials with macroporous structure and build the ionic COF by post-synthesis method.In Chapter 3,we designed a series of precursor molecules with D2 h symmetry,and tried to synthesize COF materials with two kinds of channels via imine bond,one of which is a relatively large pore channel.In Chapter 4,the ionized COF(LZU-21-CH3)was obtained by post-modification method.Although the crystalline framework was damaged during the ionization process,the properties of the pores after ionization were studied by the adsorption of the dye and the identification of the anions.Based on this,we obtained a crystalline material LZU-28-H by post-modification of stable LZU-28.The absorption property of LZU-28-H toward the dyes was also studied.