Preparation Of Novel Porous Organic Salts And Its Application In Atmospheric Water Harvester And Proton Conduction

Porous organic materials are a kind of porous materials only composed of organic compounds.Due to their low skeleton density,high specific surface area,large porosity and pore volume,excellent solvent and thermal stability,they are widely used in many fields,such as gas storage,gas separation,catalysis,atmospheric water collector and proton conduction.In addition,the monomers of organic porous materials are complex and diverse,and the synthesis methods are various,so they include:Hyper-cross-linked polymers(HCPs),Polymers of intrinsic microporosity(PIMs),Conjugated microporous polymers(CMPs),Covalent organic frameworks(COFs),Covalent triazine frameworks(CTFs),Porous aromatic frameworks(PAFs),Porous organic cages(POCs)and Crystalline porous organic salts(CPOSs).As a kind of organic porous materials,Crystalline porous organic salts are a kind of organic salt materials with permanent pores,which is connected by ionic bonds between organic acids and organic bases.As a new type of organic porous material,it is still in its infancy and faces some problems.For example,most of the porous organic salts cannot maintain the skeleton structure after removing the guest molecules,and do not have permanent porosity.Therefore,it is very important to continue to develop new types of porous organic salts with permanent porosity,which can not only enrich the types of porous organic salts,but also promote the progress of their synthesis strategies.In addition,the synthesis of new porous organic salts with different application values can not only expand their application scope and improve their competitiveness with other materials,but also promote the research and development enthusiasm of scientific researchers and accelerate the development of porous organic salt materials.In this paper,a series of new porous organic salts were synthesized,which not only enriched the types of porous organic salts,but also applied to new technical fields and expanded their application scope.In addition,we prepared large single crystals and porous organic salts with different structures to study the relationship between their structures and properties,which is of great significance to the regulation of the synthesis strategy of porous organic salts,the main contents are as follows:(1)In the first chapter,the development and general application of porous organic materials are reviewed,and the development process and basic properties of porous organic salts are introduced.(2)In chapter 2,we prepared the Crystalline porous organic salts CPOS-9 by using tetra(4-amidophenyl)methane and tetra(4-sulfophenyl)methane as monomers in the mixed solvent of water and methanol at room temperature.Due to the polar channels and high hydrophilicity of porous organic salts,we measured a series of water vapor adsorption curves of CPOSs.By comparison,we found that the newly synthesized CPOS-9 has S-type water adsorption curve,which is an ideal adsorbent material for atmospheric water collector technology.The water adsorption mechanism of CPOS-9was confirmed by the simulation of Materials Studio,the FTIR measurement under different humidity,the adsorption heat calculated by steam adsorption and the apparent activation energy calculated by water adsorption kinetics.CPOSs has been applied in atmospheric water collector for the first time and its application scope has been expanded.(3)In chapter 3,by controlling the synthesis conditions,large single crystals with millimeter size were synthesized with cis,cis-1,3,5-triaminocyclohexane·3HBr and pyromellitic acid in the presence of water and methanol,and their appearance was regular parallelepiped shape.It is possible for us to study the proton conduction in different faces.Subsequently,we studied the proton conductivity between different faces of CPOS-10 by electrochemical impedance spectroscopy,and found the correlation between the anisotropic proton conductivity and the crystal structure through one-to-one correspondence with the crystal structure between different faces of CPOS-10.The mechanism of anisotropic proton conduction in CPOSs is explained to deepen our understanding of proton conduction in CPOSs.(4)In chapter 4,we prepared three different CPOSs using the same monomer tetra(4-sulfophenyl)methane and piperazine in different growth solvents.The structure and thermal stability of CPOSs were studied by XRD,¹H NMR,FTIR and TGA.CO₂adsorption showed that the three CPOSs had permanent porosity,and the microporous surface areas were 97.6 m² g^-1,73.0 m² g^-1 and 21.4 m² g^-1,respectively.After that,we studied the proton conductivities of three CPOSs by electrochemical impedance spectroscopy,and found that their proton conductivities were different.Among them,the proton conductivity of CPOS-11-DMF synthesized in water and DMF was as high as 1.36×10^-2 S cm^-1 at 40?and 98%RH.The experimental results show that we successfully control the structure of porous organic salt by changing the type of solvent,which affects the proton conductivity of porous organic salt and realizes the macro-control from structure to property and obtain a porous organic salt with high proton conductivity.