Construction And Adsorption Properties Of Porous Vinyl Polymers Containing Metal Coordination Structure

A porous coordination Polymer typified by a metal organic framework?MOF?is a type of porous material formed by a metal ion and an organic ligand through a coordination bond.In recent years,porous coordination polymers have exhibited excellent properties in terms of light,electricity and magnetism due to their structural particularity,diversity and designability.However,many porous coordination polymers are stringent in terms of synthesis.At the same time,its overall framework structure is constructed by coordination bonds,resulting in poor structural stability and sensitivity to acid,alkali,water and air,thus limiting its application.Although the covalent organic framework material has the advantages of good stability,the selective adsorption separation ability of unfunctionalized COFs is poor,and the selective adsorption capacity can be improved by metal doping.Based on this,the paper designs a A covalently bonded novel coordinating/covalent hybrid porous polymer containing a coordination structure,the covalently bonded moiety is used to improve the stability of the skeleton,and the coordination structure is used to maintain the functionality of the material,such as gas,metal ions,etc.Selective adsorption,etc.In this paper,a new porous coordination/covalent hybrid polymer?PCOHP?was synthesized by the strategy of“first coordination and then Polymerization”.The method constructs a porous coordination Polymer by covalent bond connection,and the preparation conditions are mild.At the same time,a covalent bond framework is introduced into the coordination bond framework to form a hybrid structure,which gives the framework more excellent stability.In addition,PCOHP also exhibits versatility,which not only selectively adsorbs carbon dioxide,but also has selective fluorescence quenching effect on copper ions,so it has a good application prospect.The specific research work of the thesis is as follows:1.The secondary structural unit bis?4-vinylpyridine?zinc complex?ZnVP₂?was constructed by the coordination of 4-vinylpyridine?4-VP?with zinc ions.The polymerization can be achieved by using a vinyl functional group at both ends of ZnVP₂ to obtain a Poly?ZnVP₂?porous polymer material.The results show that the polymerization is achieved by a double bond addition reaction,and the coordination bond can be better retained during the polymerization process.Poly?ZnVP₂?has good thermal stability and T₅%is about 250°C.Poly?ZnVP₂?is an amorphous layered porous structure containing mesoporous and microporous structures with a specific surface area of 251m²/g.Poly?ZnVP₂?has CO₂adsorption performance,and the CO₂ adsorption capacity at room temperature is 21.1 mg/g,and it has good CO₂/N₂ selectivity?selectivity is 170?.Poly?ZnVP₂?has fluorescence properties(?_ex=312nm,?_em=412nm).It has selective fluorescence quenching and color change effect on Cu ions,and can be used for Cu²⁺detection with a detection limit of 76.6ppb.At the same time,the Polymer also exhibits a good solvent fluorescence response and exhibits a certain fluorescence quenching effect in a highly polar solvent.2.Copolymerization by coordination of the secondary structural unit ZnVP₂ and divinylbenzene?DVB?to obtain a porous polymer material?Poly?ZnVP₂-co-DVB??in which the coordination framework and the covalent bond framework are hybridized.Structural characterization results indicate that the polymer is also polymerized by double bond addition.The acid hydrolysis experiment showed that the pyridyl group remained in the Poly(ZnVP₂-co-DVB skeleton structure by acid hydrolysis treatment.Poly?ZnVP₂-co-DVB?was an amorphous layered mesoporous material with a specific surface area of 89m²/g.Poly?ZnVP₂-co-DVB?has CO₂ adsorption performance,and the CO₂ adsorption capacity at normal temperature is 3.132mg/g.Poly?ZnVP₂-co-DVB?has fluorescence performance(?_ex=320nm,?_em=389nm),which has a choice for Cu ions.Fluorescence quenching and color change effect,the color change occurs in the Cu ion solution within 3 min,which can be used for the detection of metal Cu ions.At the same time,the copolymer also exhibits a good solvent fluorescence response,and when exposed to a relatively polar solvent,the emitted fluorescence intensity is weak.The copolymer not only has versatility,but also has excellent acid-base stability,greatly expanding its pH range.In the range of pH 2-13,the porous skeleton can be completely retained.After acid-base treatment,the skeleton and zinc ions can be re-coordinated to obtain a regenerated polymer.The regenerated polymer still has a good fluorescence quenching response and color response to Cu²⁺.