Design Synthesis And Application Of Silane-based Porous Organic Polymers

Porous organic polymers?POPs?with various synthetic methods and adjustable pore properties are a kind of porous materials composed of organic structural units.POPs are widely applied in catalysis,photoelectricity,lithium ion battery,sensing,gas storage and separation,wastewater treatment,and membrane due to their abundant pore structures and excellent pore properties.According to their chemical structures,POPs are mainly divided into covalent organic frameworks?COFs?,polymers of intrinsic microporosity?PIMs?,conjugated microporous polymers?CMPs?,and hyper-cross-linked polymers?HCPs?.Recently,it is difficult for POPs to meet the demands in their practical applications duo to the limited preparations of monomers and the difficult control of pore structures.Therefore,the design synthesis of new building blocks,the preparation of new POPs and the effective control of the pore structures are still a major research issue and of great significance for the development of POPs.The main task of this work is to design synthesis a series of new porous hyper-cross-kinked polymers materials based on the phenylsilane.The structures of the resulted porous polymer materials are characterized and the pore properties of them are determined via the nitrogen adsorption-desorption isotherms at 77.3 K.All the results show that phenylsilane as the monomer reacted with the external cross-linker could obtain amorphous silane-based hyper-cross-linked polymers?Si-HCPs?materials with high thermostabilities and abundant pore structures.These Si-HCPs materials are applied in dye adsorption,CO₂ capture,H₂ storage,supercapacitor and fluorescence detection of metal ions,and their properties in such fields are also studied.The main contents are listed as follows:1.A series of Si-HCPs are synthesized by the Friedel-Crafts alkylation polymerization of dimethyldiphenylsiane,methyltriphenylsilane and triphenylsilane as the monomer with formaldehyde dimethyl acetal?FDA?as the cross-linker and their structures and morphologies are characterized.The effects of the kind of monomer and the dosage of the external cross-linker on the porosity of Si-HCPs are investigated.The results demonstrate that the surface areas(441-1205 m² g^–1)and the pore size distributions of all Si-HCPs are adjustable through changing the monomer and the dosage of the external cross-linker.Applications of the Si-HCPs materials as dye adsorption and gas adsorption materials are exploited.The materials show an excellent adsorption capacity(750-952 mg g^–1)for Congo red dye and retain remarkable recyclability.And the Si-HCPs materials possess the promising value in CO₂ capture(3.42-7.53 wt.%,0.78-1.71 mmol L^–1 at 298.1 K under 1.12 bar)and H₂ storage(1.17-1.25 wt.%,5.87-6.25 mmol L^–1 at 77.3 K under 1.12 bar).2.A kind of new Si-HCPs materials have been synthesized through a mild Friedel-Crafts reaction with cyanuric chloride as the external cross-linker and dimethyldiphenylsiane,methyltriphenylsilane and triphenylsilane as the building blocks.The prepared materials exhibit excellent CO₂ capture capacity of 7.9-8.9 wt.%(1.81-2.03 mmol L^–1)at 298.1 K under 1.12 bar.After chemical activation by KOH and carbonization,the obtained materials could be applied in supercapacitor and show good capacitive performance centering from 226.3 to 263.5 F g^–1 at 1 A g^–1.3.Dimethyldiphenylsiane,methyltriphenylsilane and triphenylsilane react with1,4-dimethoxybenzene as the external cross-linker to synthesize a series of novel Si-HCPs.The resulted materials with?-?and d-p conjugate structures exhibit fluorescence property.This kind of Si-HCPs materials and polystyrene maleic anhydride?PSMA?are composited into nanoparticles which could identify Fe³⁺ions effectively stating the Si-HCPs materials have a certain value in fluorescence.In summary,the work provides new methods and research ideas for the preparations and property regulations of porous polymer materials and also offers significant referential values for the applications of them in such fields.