| The adsorption and separation of light hydrocarbons(C2H2,CZH4,C2H6,CH4)are key industrial processes.The traditional separation technology is low temperature fractional distillation with energy-demanding.Porous materials,as a promising adsorption,make it possible to separate light hydrocarbons more economically and efficiently.For tetraphenylethylene has unique optical properties,rigid skeleton and easy functionalization,five tetraphenylethylene-based porous materials have been synthesized and applied to gas adsorption selectivity and separation.First,Compound 1([Cu2Cl(H2O)(TTPE)]ˇ(CH3)2NH2ˇ2H2OˇSolvent)was constructed from H4TTPE,which immersed in MeOH formed Compound 1' with Single-Crystal to Single-Crystal(SC-SC)transformation.It is found that the SC-SC transformation has a great influence on the gas adsorption performance,and the BET specific surface area is changed from 629.5 to 927.06 m2 g-1.The adsorption of CO2 and C2H2)increased significantly from 86.18 and 117.52 m2 g-1 to 107.44 and 135.20 m2.g-1 before and after the SC-SC transformation at 273 K.Dynamic breakthrough experiments were conducted to demonstrate the separation performance of Compound 1'using(15:85)molar CO2/CH4 and equimolar C2H2/CH4 gas mixture,and the results showed that both CO2/N2 and C-2H2/CH4 could be effectively separated.Then,by using FH4TCPE,a multi-functional one-dimensional Zn chain MOF(Compound 2)with high thermal stability was synthesized.Compound 2 has different fluorescence characteristics from the original ligand and stable porous adsorption.By utilizing IAST to calculate the adsorption selectivity of equimolar C2H6/CH4 mixtures,we found the adsorption selectivity is 29.67.At last,by one-pot method,three cases of high thermal and physicochemical resistance polyimide POPs(P1,P2 and P3)were synthesized using three diacid anhydrides and tetrakis(4-aminophenyl)ethylene.With the increase of the length of the anhydride,the pores of the three polymers successively transition from micropores to macropores and their BET specific surface areas are 389.4,481.6 and 140.0 m2ˇg-1,respectively.When utilizing IAST to calculate the adsorption selectivitives of gas mixtures on the three porous polyimides,they all have the best effect on C2H/CH4,followed by 121.73,117.95 and 156.54.In conclusion,this paper not only synthesize some porous materials for gas adsorption and separation,but also discuss an interesting way to regulate gas adsorption performance by controlling SC-SC transformation,which contribute to storage and separation of light hydrocarbons. |
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