A new aromatic diamine,3,5-diaminobenzoylpiperazine （3,5-DABP）,was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3...A new aromatic diamine,3,5-diaminobenzoylpiperazine （3,5-DABP）,was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3,5-DABP as aqueous monomer and trimesoyl chloride （TMC） as organic monomer,thin film composite （TFC） nanofiltration membranes were prepared by interfacial polymerization technology.The salt rejection order of these TFC membranes is Na2SO4MgSO4MgCl2NaCl.This sequence indicates that the membranes are negatively charged.展开更多
Three composite reverse osmosis membranes were prepared from m-phenylenediamine (MPD) and trimesoyl chloride (TMC), 5-chloroformate-isophthaloyl chloride (CFIC), 5-isocynate-isophthaloyl chloride (ICIC) respectively t...Three composite reverse osmosis membranes were prepared from m-phenylenediamine (MPD) and trimesoyl chloride (TMC), 5-chloroformate-isophthaloyl chloride (CFIC), 5-isocynate-isophthaloyl chloride (ICIC) respectively through the interfacial polymerization technique on the polysulphone supporting membrane.The membranes produced were characterized by using permeation experiments with salt water, attenuated total reflectance infrared (ATR-IR), and X-ray photoelectronic spectroscopy (XPS).This study showed that with the increase of NaCl concentration, the flux of the three membranes decreased; the rejection of TMC/MPD, ICIC/MPD composite membranes increased firstly and then decreased; but the rejection of CFIC/MPD composite membrane kept steady.According to the ATR-IR and XPS results, the active layer of three membranes was composed of crosslinked polymer and linear polymer with pendant; all three composite membranes contained amide functional group( —CONH? ゛nd carboxyl acid functional group( —COOH ); the ICIC/MPD composite membrane contained urea functional group( —NHCONH? ? the CFIC/MPD composite membrane also contains urethane functional group( —OCONH? ゛nd hydroxyl functional group( —OH ).The hydroxyl functional group could lead to high rejection and low flux.展开更多
Initial reverse osmosis composite membrane(IniM) is a thin-film-composite(TFC) membrane prepared through the interfacial polymerization technique without post-treatment,such as water washing,heating,etc.Trimesoyl chlo...Initial reverse osmosis composite membrane(IniM) is a thin-film-composite(TFC) membrane prepared through the interfacial polymerization technique without post-treatment,such as water washing,heating,etc.Trimesoyl chloride(TMC) and m-phenylenediamine(MPD) were used to prepare some IniMs through the interfacial polymerization technique on the polysulphone supporting membrane without heat-treatment and washing.Then the in situ modification was performed with tetraethylenepentamine(TEPA) on the surface of IniMs.Modified membranes were characterized by using X-ray photoelectronic spectroscopy(XPS),contacting angle and permeation experiments with salt water of different pH values.The results showed that tetraethylenepentamine reacted with acyl chloride(—COCl) on the surface of IniM,because the ratio of O/N of the modified membrane surface was lower than that of unmodified membrane.Furthermore,the contacting angle of modified membrane was larger than that of unmodified membrane.It is interesting that the water flux and rejection of modified membrane decreased with increasing pH value for sodium chloride solution,while the unmodified membrane was just on the contrary.The reason was that functional groups on the modified and unmodified membrane were different,the former were amino(—NH2) and imino(NH),and the latter was carboxyl(—COOH).展开更多
A polypiperazine amide （PA）/polysulfone （PSF） thin film composite （TFC） was prepared by interracial polymerization （IP） using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solu...A polypiperazine amide （PA）/polysulfone （PSF） thin film composite （TFC） was prepared by interracial polymerization （IP） using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as the water phase on a porous polysulfone hollow fiber substrate. Its separating behaviors were investigated systematically to various salts such as NaCl KCl, Na2SO4, MgCl2, CaCl2 and MgSO4, showing the highest rejection rate to Na2SO4, the second to MgSO4 the third to MgCl2 and CaCl2, and the lowest to KCI, NaCl, being 99%, 98%, 70%, 60%, 15% and 10% respectively. Under an increasing pressure or with time, the rejection rate of the TFC rises to a plateau. To various concentration of the feed, the rejection rate reduced gradually with the higher concentration.展开更多
基金Supported by the National Natural Science Foundation of China（21076176） the Research and Development Project of Tangshan（10140201C-3）+1 种基金 the Research and Development Project of Hebei Province（07275113） the Research Fund of Tangshan Normal College
文摘A new aromatic diamine,3,5-diaminobenzoylpiperazine （3,5-DABP）,was synthesized from 3,5-diaminobenzoic acid and 1-formyl piperazine.The structure of 3,5-DABP was identified by FT-IR spectra and 1H NMR spectra.With 3,5-DABP as aqueous monomer and trimesoyl chloride （TMC） as organic monomer,thin film composite （TFC） nanofiltration membranes were prepared by interfacial polymerization technology.The salt rejection order of these TFC membranes is Na2SO4MgSO4MgCl2NaCl.This sequence indicates that the membranes are negatively charged.
文摘Three composite reverse osmosis membranes were prepared from m-phenylenediamine (MPD) and trimesoyl chloride (TMC), 5-chloroformate-isophthaloyl chloride (CFIC), 5-isocynate-isophthaloyl chloride (ICIC) respectively through the interfacial polymerization technique on the polysulphone supporting membrane.The membranes produced were characterized by using permeation experiments with salt water, attenuated total reflectance infrared (ATR-IR), and X-ray photoelectronic spectroscopy (XPS).This study showed that with the increase of NaCl concentration, the flux of the three membranes decreased; the rejection of TMC/MPD, ICIC/MPD composite membranes increased firstly and then decreased; but the rejection of CFIC/MPD composite membrane kept steady.According to the ATR-IR and XPS results, the active layer of three membranes was composed of crosslinked polymer and linear polymer with pendant; all three composite membranes contained amide functional group( —CONH? ゛nd carboxyl acid functional group( —COOH ); the ICIC/MPD composite membrane contained urea functional group( —NHCONH? ? the CFIC/MPD composite membrane also contains urethane functional group( —OCONH? ゛nd hydroxyl functional group( —OH ).The hydroxyl functional group could lead to high rejection and low flux.
文摘Initial reverse osmosis composite membrane(IniM) is a thin-film-composite(TFC) membrane prepared through the interfacial polymerization technique without post-treatment,such as water washing,heating,etc.Trimesoyl chloride(TMC) and m-phenylenediamine(MPD) were used to prepare some IniMs through the interfacial polymerization technique on the polysulphone supporting membrane without heat-treatment and washing.Then the in situ modification was performed with tetraethylenepentamine(TEPA) on the surface of IniMs.Modified membranes were characterized by using X-ray photoelectronic spectroscopy(XPS),contacting angle and permeation experiments with salt water of different pH values.The results showed that tetraethylenepentamine reacted with acyl chloride(—COCl) on the surface of IniM,because the ratio of O/N of the modified membrane surface was lower than that of unmodified membrane.Furthermore,the contacting angle of modified membrane was larger than that of unmodified membrane.It is interesting that the water flux and rejection of modified membrane decreased with increasing pH value for sodium chloride solution,while the unmodified membrane was just on the contrary.The reason was that functional groups on the modified and unmodified membrane were different,the former were amino(—NH2) and imino(NH),and the latter was carboxyl(—COOH).
基金China High-Tech R&D Program (863 Program) #2002AA302619 and Tianjin Science and Technology Develop Program #05YFGDGX10000-2
文摘A polypiperazine amide （PA）/polysulfone （PSF） thin film composite （TFC） was prepared by interracial polymerization （IP） using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as the water phase on a porous polysulfone hollow fiber substrate. Its separating behaviors were investigated systematically to various salts such as NaCl KCl, Na2SO4, MgCl2, CaCl2 and MgSO4, showing the highest rejection rate to Na2SO4, the second to MgSO4 the third to MgCl2 and CaCl2, and the lowest to KCI, NaCl, being 99%, 98%, 70%, 60%, 15% and 10% respectively. Under an increasing pressure or with time, the rejection rate of the TFC rises to a plateau. To various concentration of the feed, the rejection rate reduced gradually with the higher concentration.
