Synthesis Of Novel Porous Organic Polymers For Applications Of Environment And Energy Fields

With the development of society,energy crisis and environmental pollution have received more and more attention.Aiming to that,the non-renewable and environmental pollution caused by traditional energy sources urgently requires the development of new energy sources such as nuclear energy,wind energy,tidal energy,solar energy and electric energy.Moreover,the capturing carbon dioxide into new energy sources has also become a mainstream medium and is considered a medium-term solution.In recent years,porous organic polymers?POPs?linked by covalent bonds have attracted wide attention.POPs have been successfully used in gas storage and pollutant adsorption,clean energy storage,catalysis and other related fields due to their low density,good thermochemical stability,large specific surface area,tunable pore size,variety of reactive monomers and diversity of synthetic methods.This dissertation mainly focuses on the design,synthesis and application of various novel POPs.It mainly includes three sections as following:First:radioiodine(¹²⁹I and ¹³¹I)emission from the nuclear waste stream arouses enormous apprehension because of its quick diffusion and radiological contamination.Conventional porous adsorbents such as zeolites and carbon with rigid skeleton and constant pore volume reveal a limited performance for reliable storage.Here,a series of soft porous aromatic frameworks?PAFs?with additional?-conjugated fragments was disclosed for use in physicochemical stable mediums.Due to the flexibility oftertiary amine centers,the PAF products provided sufficent space for the binding sites,and thus exhibited a considerable capability for iodine capture from both gaseous and soluble environments.The obtained capacity of PAFs was ca.1.6 times higher than that of PAF-1 which possesses similar aromatic constituents featuring a ultra-large specific surface area(BET=5600 m² g^-1).Second:however,the intrinsic low conductivity of porous organic polymers limits its application as a supercapacitor.Direct carbonization of porous organic polymers may be a good method to improve its conductivity and specific surface area for used in supercapacitors and carbon dioxide adsorption.The precursor of novel porous organic polymers?LNU-5,LNU-6,LNU-7?were synthesized using Sonogashira coupling reaction of 1,4-diethynylbenzene and aromatic monomers rich in carbon source.Porous carbon?C-LNU-5,C-LNU-6,C-LNU-7?carbonized from novel porous organic polymers have shown outstanding capability of conductivity and high surface area for adsorption and supercapacitor and been the proved by the experimental.For example,porous carbon exhibited respectively high CO₂ adsorption of 2.75 mmol g^-1,3.17 mmol g^-11 and 2.80 mmol g^-1 at 1 bar and 273 K,and exhibited respectively specific capacitance of 229 F g^-1,125 F g^-11 and 122 F g^-1 at the scan rate of 2 mV s^-1.Third:novel porous organic polymer was synthesized by a standard Sonogashira coupling with 1,4-dibromonaphthalene and 1,4-diethynylbenzene and it was found that the monomer concentration play crucial roles in the formation of the morphology with tubular T-LNU and bulk B-LNU.Porous carbon?T-LNU-900 B-LNU-900?carbonized and optimized from novel porous organic polymers exhibited greatest specific surface.B-LNU-900 show highest CO₂ adsorption of 3.80 mmol g^-1 at 273 K and 1 bar.The T-LNU-900 had a specific capacitance of 285 F g^-1 at the scan rate of2 mV s^-1.And the capacitance retention rate was as high as 91.2%after 5000 cycles.The influence of morphology on electrochemical performance of porous carbon materials was further studied.Under the same conditions,the porous carbon of the tubular morphology is superior to the porous carbon of the bulk morphology in terms of capacitors.In conclusion,a series of functionalization porous organic polymers were design and synthesis for capturing radioiodine,carbon dioxide adsorption and supercapacitors.This provides new directions for designing porous organic polymers.