Preparation Of Covalent Organic Frameworks And ILs/COFs Composite

Because"classical"inorganic porous crystalline materials?zeolite and inorganic-organic metal hybrid organic framework?MOF?materials?and organic materials lack of organic or long-range order properties,they have certain defects.Therefore,covalent organic framework materials?COFs?are complementary to inorganic and organic porous materials by virtue of their organic and crystalline properties.Research in this field has appeared as early as 2005.So far,a large number of such structures have been designed and synthesized,indicating that COFs has a huge design space.The synthesized COFs can also be functionalized by post-synthesis modification methods.In short,COFs is a crystalline porous organic polymer with clear crystal structure,low density,good chemical stability,large surface area and easily customizable properties,and has great potential in a variety of applications,Examples include catalysis,gas adsorption,separation,drug delivery,functional devices,and supercapacitors.This paper is mainly composed of the following parts:In the first part,the design and synthesis principles of COFs are first introduced,that is,they are designed by using modular design principles,which are also used to synthesize other types of porous materials?including metal organic framework materials?.In addition,when synthesizing COFs,it is necessary to select an appropriate reaction type with slight reversibility,because the condensation reaction type with slight reversibility can self-correct by adjusting the thermodynamic balance during bond formation,and finally form a thermodynamically stable crystal structure.The most common types of reactions used to prepare COFs include boroxine,borate esters,imines,hydrazones,azines,?-ketoenamines,imides,and cyanovinylidene.Then introduced the post-synthesis modification of COFs.The post-synthesis modification strategies for COFs are mainly divided into post-synthesis modification by metallization,post-synthesis modification on COFs skeleton,post-synthesis modification by functional group conversion,and post-modification of COFs by monomer truncation strategy.Finally,the application of COFs is introduced,mainly reflected in the application of separation,energy storage and conversion,chemical sensors,photocatalysis,white light emitters,photoelectric detection The application of the device and the application of the thermometer.In the second part,we synthesized two new types of COFs,namely 2CH₃-COF and 4CH₃-COF.Before synthesizing these two COFs,we first carried out the synthesis of monomer?2,2',7,7'-tetramethoxy-3,3',6,6'-tetraformyl-9,9'-spirobiflu orene?.Then we explored the reaction conditions of these two COFs.In addition,in order to analyze the crystal structure of these two COFs,we simulated the non-penetrating,double-penetrating and triple-penetrating PXRD spectra of COFs,and found that the structure of the two COFs coincides with the non-penetrating structure.Then we carried out a series of characterization of COFs,through Fourier infrared,SEM and thermogravimetric test,etc.,revealed the successful synthesis of COFs,morphology and stability information.Finally,we conducted tests on COFs for nitrogen adsorption,and obtained information on the pore size distribution,BET specific surface area,and nitrogen adsorption of COFs.In the third part,to obtain the[HEMIM][DCA]/CH₃-COFs composite,the CH₃-COFs prepared in the second chapter were modified.In this process,we explored the relationship between the load capacity of the ILs and gas adsorption and separation performance,thus obtaining the optimal load capacity of the ILs.Through SEM analysis of[HEMIM][DCA]/CH₃-COFs composites,we found that the morphology of COFs changes greatly after loading ILs.The IR diagram shows that ILs characteristic peaks can be observed compared with the materials unloaded ionic liquid.In the fourth part,the above contents are summarized and the application of COFs is prospected.