The intrinsic viscosity and viscometric interaction parameters of perfluorosulfonic acid （PFSA） and poly（vinyl alcohol） （PVA） were measured by dilute solution viscometry. The miscibility between PFSA and PVA was...The intrinsic viscosity and viscometric interaction parameters of perfluorosulfonic acid （PFSA） and poly（vinyl alcohol） （PVA） were measured by dilute solution viscometry. The miscibility between PFSA and PVA was estimated by the criteria of AB and μ. The results indicated that PFSA and PVA were completely miscible for any weight fraction in aqueous solution.展开更多
In this work,a series of high strength,thermal stable and antioxidant proton exchange membranes were designed with solution processible polybenzimidazole(PBI)as the matrix and perfluorosulfonic acid(PFSA)as the fortif...In this work,a series of high strength,thermal stable and antioxidant proton exchange membranes were designed with solution processible polybenzimidazole(PBI)as the matrix and perfluorosulfonic acid(PFSA)as the fortifier for proton exchange.Solution processible PBI was successfully synthesized by introducing 4,4’-dicarboxydiphenyl ether into the molecular chains of PBI.PFSA/PBI composite membranes were obtained by solution blending and film casting.PBI and PFSA/PBI composite membranes exhibited greatly enhanced tensile strength and Young’s modulus compared to PFSA.PFSA/PBI composite membranes are stable below 300℃ which are suitable for practical application in proton exchange membrane fuel cells.The PFSA/PBI composite membranes show good dimensional stability with low water uptake and swelling rate.The PFSA/PBI composite membranes also exhibit excellent antioxidation stability with less than 5%initial mass loss over 120 h in Fenton reagent.The proton conductivity of PBI is greatly enhanced by blending with PFSA and the proton conductivities of the composite membranes are increased with the raise of PFSA content and temperature.This work offers valuable insights into the exploration of PBI based high-performance proton exchange membranes.展开更多
High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore for...High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore former and as a hydrophilic component of the membranes and polyethylene glycol （Mw = 400） （PEG400） as a pore forming agent. The effects of the presence of PEG and the concentration of the PFSA on the phase separation of the casting solutions and on the morphologies and performance of UF membranes including their porosity, water flux, rejection of bovine serum albumin （BSA） protein, and anti-fouling property were investigated. Phase diagrams, viscosities and the phase separations upon exposure to water vapor showed that both PEG400 and PFSA promoted demixing of the casting solution. Scanning electron microscopy measurements showed that the PVDF-PFSA blend membranes had more macropores and finger-like structures than the native PVDF membranes. The PVDF-PFSA membrane （5 wt-% PEG400 ＋ 5 wt-% PFSA） had a pure water flux of 141.7L/m2.h, a BSA rejection of 90.1% and a relative pure water flux reduction （RFR） of 15.28%. These properties were greatly superior to those of the native PVDF membrane （pure water flux of 5.6 L/m2. h, BSA rejection of 96.3% and RFR of 42.86%）.展开更多
基金supported by the Innovation Program of Shanghai Municipal Education Commission (Grant No.09YZ163)
文摘The intrinsic viscosity and viscometric interaction parameters of perfluorosulfonic acid （PFSA） and poly（vinyl alcohol） （PVA） were measured by dilute solution viscometry. The miscibility between PFSA and PVA was estimated by the criteria of AB and μ. The results indicated that PFSA and PVA were completely miscible for any weight fraction in aqueous solution.
基金financially supported by the National Natural Science Foundation of China(Nos.22005147 and 21774053)。
文摘In this work,a series of high strength,thermal stable and antioxidant proton exchange membranes were designed with solution processible polybenzimidazole(PBI)as the matrix and perfluorosulfonic acid(PFSA)as the fortifier for proton exchange.Solution processible PBI was successfully synthesized by introducing 4,4’-dicarboxydiphenyl ether into the molecular chains of PBI.PFSA/PBI composite membranes were obtained by solution blending and film casting.PBI and PFSA/PBI composite membranes exhibited greatly enhanced tensile strength and Young’s modulus compared to PFSA.PFSA/PBI composite membranes are stable below 300℃ which are suitable for practical application in proton exchange membrane fuel cells.The PFSA/PBI composite membranes show good dimensional stability with low water uptake and swelling rate.The PFSA/PBI composite membranes also exhibit excellent antioxidation stability with less than 5%initial mass loss over 120 h in Fenton reagent.The proton conductivity of PBI is greatly enhanced by blending with PFSA and the proton conductivities of the composite membranes are increased with the raise of PFSA content and temperature.This work offers valuable insights into the exploration of PBI based high-performance proton exchange membranes.
基金Acknowledgements The work was supported by the National Natural Science Foundation of China （Grant No. 20904031） and the Shanghai Leading Academic Discipline Project （No, B202）. Thanks for Instrumental Analysis Center of Shanghai Jiao Tong University.
文摘High performance polyvinylidene fluoride （PVDF） flat sheet ultrafiltration （UF） membranes have been prepared by an immersion precipitation phase inversion method using perfluorosulfonic acid （PFSA） as a pore former and as a hydrophilic component of the membranes and polyethylene glycol （Mw = 400） （PEG400） as a pore forming agent. The effects of the presence of PEG and the concentration of the PFSA on the phase separation of the casting solutions and on the morphologies and performance of UF membranes including their porosity, water flux, rejection of bovine serum albumin （BSA） protein, and anti-fouling property were investigated. Phase diagrams, viscosities and the phase separations upon exposure to water vapor showed that both PEG400 and PFSA promoted demixing of the casting solution. Scanning electron microscopy measurements showed that the PVDF-PFSA blend membranes had more macropores and finger-like structures than the native PVDF membranes. The PVDF-PFSA membrane （5 wt-% PEG400 ＋ 5 wt-% PFSA） had a pure water flux of 141.7L/m2.h, a BSA rejection of 90.1% and a relative pure water flux reduction （RFR） of 15.28%. These properties were greatly superior to those of the native PVDF membrane （pure water flux of 5.6 L/m2. h, BSA rejection of 96.3% and RFR of 42.86%）.
