To improve the hydrophilicity and anti-fouling performance in water treatment,both entrapped method and deposited method were used to modify polyvinylidene fluoride(PVDF)porous membrane with composite Al2O3/TiO2 nano-...To improve the hydrophilicity and anti-fouling performance in water treatment,both entrapped method and deposited method were used to modify polyvinylidene fluoride(PVDF)porous membrane with composite Al2O3/TiO2 nano-particles.Neat PVDF membrane was prepared and its property was also compared with that of the modified membranes.Membrane permeation flux and anti-fouling performance were measured using a membrane cell.The contact angle between water and membrane surface was detected in order to denote the membrane hydrophilicity.Membrane morphology and surface structure were examined by atomic-force microscopy(AFM)and scanning electron microscopy(SEM).Experimental results showed that modified membranes had higher permeation fluxes than that of the neat PVDF membrane.The addition of nano-particles altered membrane surface morphology and increased surface roughness.Due to the hydrophilicity of nano-particles,however,the membrane anti-fouling performance was improved instead of worsened.The entrapped membrane exhibited better anti-fouling performance than the deposited membrane and the neat membrane.展开更多
Three phase PebaxMH 1657/PEG-ran-PPG/CuBTC（polymer/liquid/solid） was successfully deposited as a selective layer on a porous Polysulfone（PSF） support. In fact, the beneficial properties of PEG（high selectivity） ...Three phase PebaxMH 1657/PEG-ran-PPG/CuBTC（polymer/liquid/solid） was successfully deposited as a selective layer on a porous Polysulfone（PSF） support. In fact, the beneficial properties of PEG（high selectivity） with those of PPG（high permeability, amorphous） have been combined with superior properties of mixed matrix membrane（MMMs）. The membranes were characterized by DSC, TGA and SEM, while CuBTC was characterized by COand CHadsorption test. Statistically based experimental design（central composite design, CCD） was applied to analyze and optimize the effect of PEG-ran-PPG（10–50 wt%） and CuBTC（0–20 wt%） mass contents on the COpermeance and CO/CHideal selectivity. Based on the regression coefficients of the obtained models, the COpermeance was notably influenced by PEG-ran-PPG,while CuBTC has the most significant effect on the CO/CHideal selectivity. Under the optimum conditions（PEG-ran-PPG: 32.76 wt% and CuBTC: 20 wt%）, nearly 620% increase in the COpermeance and43% enhancement in the CO/CHideal selectivity was observed compared to the neat Pebax. The effect of pressure（3, 9 and 15 bar） on the pure and mixed gas separation performance of the composite membranes was also investigated. The high solubility of COin the membranes resulted in the enhancement of COpermeability with increase in gas pressure.展开更多
基金Sponsored by the National High Technology Research and Development Program of China(863 Program)(Grant No.2006AA06Z303)the National Natural Science Foundation of China(Grant No.50778050)+2 种基金the Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period(Grant No.2006BAJ08B09)the National Creative Research Groups(Grant No.50821002)the Key Scientific and Technological Project of Heilongjiang Province(Grant No.GB06C20403)
文摘To improve the hydrophilicity and anti-fouling performance in water treatment,both entrapped method and deposited method were used to modify polyvinylidene fluoride(PVDF)porous membrane with composite Al2O3/TiO2 nano-particles.Neat PVDF membrane was prepared and its property was also compared with that of the modified membranes.Membrane permeation flux and anti-fouling performance were measured using a membrane cell.The contact angle between water and membrane surface was detected in order to denote the membrane hydrophilicity.Membrane morphology and surface structure were examined by atomic-force microscopy(AFM)and scanning electron microscopy(SEM).Experimental results showed that modified membranes had higher permeation fluxes than that of the neat PVDF membrane.The addition of nano-particles altered membrane surface morphology and increased surface roughness.Due to the hydrophilicity of nano-particles,however,the membrane anti-fouling performance was improved instead of worsened.The entrapped membrane exhibited better anti-fouling performance than the deposited membrane and the neat membrane.
文摘Three phase PebaxMH 1657/PEG-ran-PPG/CuBTC（polymer/liquid/solid） was successfully deposited as a selective layer on a porous Polysulfone（PSF） support. In fact, the beneficial properties of PEG（high selectivity） with those of PPG（high permeability, amorphous） have been combined with superior properties of mixed matrix membrane（MMMs）. The membranes were characterized by DSC, TGA and SEM, while CuBTC was characterized by COand CHadsorption test. Statistically based experimental design（central composite design, CCD） was applied to analyze and optimize the effect of PEG-ran-PPG（10–50 wt%） and CuBTC（0–20 wt%） mass contents on the COpermeance and CO/CHideal selectivity. Based on the regression coefficients of the obtained models, the COpermeance was notably influenced by PEG-ran-PPG,while CuBTC has the most significant effect on the CO/CHideal selectivity. Under the optimum conditions（PEG-ran-PPG: 32.76 wt% and CuBTC: 20 wt%）, nearly 620% increase in the COpermeance and43% enhancement in the CO/CHideal selectivity was observed compared to the neat Pebax. The effect of pressure（3, 9 and 15 bar） on the pure and mixed gas separation performance of the composite membranes was also investigated. The high solubility of COin the membranes resulted in the enhancement of COpermeability with increase in gas pressure.
