Synthesis Of Functionalized Porous Organic Polymers And Their Applications In Environment And Energy

Since the Paris Climate Conference(COP21),many countries have begun to move towards the goal of"carbon neutrality".Clean energy is one of the important factors in achieving carbon neutrality goals.Yet modern civilization still relies heavily on oil and gas-based fossil fuels to meet its energy needs.As a clean energy,nuclear energy is considered as a substitute for traditional fossil energy and has developed rapidly in recent years.But nuclear leakage and nuclear waste also cause serious harm to the environment and human body.Among the nuclear wastes,¹³¹I with high activity and¹²⁹I with high fission rate are the two most harmful nuclides to the human body.They enter the human body through drinking water,food,etc.,increasing the risk of thyroid disease and even cancer in humans.At the same time,the wide application of nuclear energy has promoted the development of new energy storage devices due to the way that nuclear energy can generate a stable energy supply.As a new type of energy storage device,supercapacitors have the characteristics of high power,long life and environmental friendliness,and are widely used in occasions requiring instantaneous shock power.Porous organic polymers have abundant reactive sites in the backbone,which are favorable for further functionalization reactions.This characteristic allows researchers to design and prepare porous organic polymers with special structures and functions according to practical applications and apply them to the enrichment of radioactive elements and supercapacitors.(1):As an?-containing functional group,azo group can act as a chemical binding site,and as an effective mean,increases the?conjugation capacity of the skeleton,both of which are conducive to the adsorption of iodine by porous organic polymer materials in different environments.Therefore,in Chapter 2,we selected 1-(3,5-dibromophenyl)-2-phenyldiazene containing azo functional group as the building block,and prepared the porous organic polymer LNU-58 and LNU-59.They were by coupling with different boronic acid pinacol ester monomers through Suzuki reaction,and deeply explored the ability of polymers to capture iodine in different environments.The experimental results show that the adsorption of gaseous iodine by the two materials belongs to chemical adsorption,and both can reach the adsorption equilibrium within12 h,and the adsorption kinetics conform to the pseudo-second-order kinetic model.Due to the rich azo groups in the polymer backbone,the adsorption capacity of LNU-58 for gaseous iodine is as high as 3533.11 mg/g,and the adsorption capacity of LNU-59 for iodine in aqueous solution is as high as 2410.7 mg/g.Their adsorption capacity far exceeds that of many current iodine adsorbent materials,indicating that the porous organic polymers LNU-58 and LNU-59 have good application prospects in the field of radioactive iodine capture in the environment.(2):Due to the low energy barrier of the C-N bond in the cyano group has a lower energy barrier,KOH can preferentially destroy the C-N bond and then strongly corrode the network structure of the carbon material,and generate more sp~2-N active sites while optimizing the hierarchical porous structure.Therefore,in Chapter 3,we prepared alkynyl-rich porous organic polymers by Sonogashira reaction,followed by post-modification of alkynyl groups to obtain cyano-rich porous organic polymers LNU-60-CN.Using LNU-60-CN as the precursor,the new porous carbon material LNU-60-CNs was prepared at different temperatures through the action of KOH activator.Among them,LNU-60-CN-700 has high specific surface area,excellent hierarchical porous structure and abundant N and O doping,which make it have excellent electrochemical performance(993 F/g),It has shown good application prospects in the field of supercapacitor electrode materials.