Now the mining of high salt underground brine has been an important aspect of salt lake mining,which is the necessary support to the development of national economy.With the change of underground geological
Electromotive force measurements of the cell, Na-ISE|polyelectrolyte( m p(mono) ),NaCl( m a)|AgCl,Ag,are carried out at the different molalities of NaCl in aqueous poly(diallydimethylammonium chloride)(PDADMAC)and pol...Electromotive force measurements of the cell, Na-ISE|polyelectrolyte( m p(mono) ),NaCl( m a)|AgCl,Ag,are carried out at the different molalities of NaCl in aqueous poly(diallydimethylammonium chloride)(PDADMAC)and poly(anetholesulfonic acid, sodium salt)(PAS) solutions at 308.15 K. The mean activity coefficients of NaCl in aqueous polyelectrolyte solutions are determined by using the standard cell potential which are obtained from the measurements of the electromotive force of cell,Na-ISE| NaCl( m )|AgCl, Ag, combining with the Pitzer model for electrolyte solution.At different concentrations of PDADMAC solution, the mean activity coefficients of NaCl decrease monotonically as the concentrations of NaCl increase.However, for the aqueous solutions of PAS, there is a maximum value as the concentrations of NaCl increase.展开更多
A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly（allylamine hydrochloride）（PAH）/poly（vinylsulfonic acid sodium salt）（PVS） multilayers. ...A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly（allylamine hydrochloride）（PAH）/poly（vinylsulfonic acid sodium salt）（PVS） multilayers. Con- ventional polyelectrolyte multilayers of PAH/PVS are usually fabricated through electrostatic layer-by-layer（LbL） assembly, resulting in poor stability, especially in basic solutions, which leads to the urgent demand for converting weak electrostatic interactions into covalent bonds to enhance the stability of the multilayers. This stability problem has been ultimately addressed by post-infiltrating a photosensitive cross-linking agent, 4,4＇-diazostilbene-2,2＇- disulfonie acid disodium salt（DAS）, into the LbL assembled films to initiate the photochemical reaction to cross-link the multilayers. The obviously improved stability of the photo-cross-linked multilayers was demonstrated through experiments with basic solution treatments. Compared to the complete decomposition of uncross-linked multilayers in basic solution, over 74.4% of the covalently cross-linked multilayers were retained under the same conditions, even after a longer duration of basic solution treatment.展开更多
The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membr...The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process.The kinetics of complexation reaction was studied for PAASS with Co^(2+).Results showed that,under a large excess of PAASS,it takes 65,55 and 40 min at pH 5,6 and 7,respectively,to get the equilibrium of complexation.The reaction kinetics can be described by a pseudo-first-order equation.Then,the effects of various parameters on the extraction of Co^(2+)were examined in detail.Results indicated that loading ratio,pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R.Furthermore,a concentration experiment was carried out at pH 7.With increasing volume concentration factor,membrane flux declines slowly,and R value is always about 1.The concentrated retentate was used further for a decomplexation experiment.The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%.After the decomplexation step,a diafiltration experiment was performed at pH 2.5.Cobalt ions can be extracted satisfactorily from the retentate,and a purified PAASS is obtained.展开更多
基金supported by National High-tech Research and Development Projects (863): the key technology of efficient exploiting deep brine in the Yellow River delta (Contracts 2012AA061705)
文摘Now the mining of high salt underground brine has been an important aspect of salt lake mining,which is the necessary support to the development of national economy.With the change of underground geological
文摘Electromotive force measurements of the cell, Na-ISE|polyelectrolyte( m p(mono) ),NaCl( m a)|AgCl,Ag,are carried out at the different molalities of NaCl in aqueous poly(diallydimethylammonium chloride)(PDADMAC)and poly(anetholesulfonic acid, sodium salt)(PAS) solutions at 308.15 K. The mean activity coefficients of NaCl in aqueous polyelectrolyte solutions are determined by using the standard cell potential which are obtained from the measurements of the electromotive force of cell,Na-ISE| NaCl( m )|AgCl, Ag, combining with the Pitzer model for electrolyte solution.At different concentrations of PDADMAC solution, the mean activity coefficients of NaCl decrease monotonically as the concentrations of NaCl increase.However, for the aqueous solutions of PAS, there is a maximum value as the concentrations of NaCl increase.
基金Supported by the National Natural Science Foundation of China（Nos.51372125, 51302010） and the Specialized Research Fund for the Doctoral Program of Higher Education of China（No.20130010120009）.
文摘A post-photochemical cross-linking strategy was successfully demonstrated to enhance the stability of polyelectrolyte poly（allylamine hydrochloride）（PAH）/poly（vinylsulfonic acid sodium salt）（PVS） multilayers. Con- ventional polyelectrolyte multilayers of PAH/PVS are usually fabricated through electrostatic layer-by-layer（LbL） assembly, resulting in poor stability, especially in basic solutions, which leads to the urgent demand for converting weak electrostatic interactions into covalent bonds to enhance the stability of the multilayers. This stability problem has been ultimately addressed by post-infiltrating a photosensitive cross-linking agent, 4,4＇-diazostilbene-2,2＇- disulfonie acid disodium salt（DAS）, into the LbL assembled films to initiate the photochemical reaction to cross-link the multilayers. The obviously improved stability of the photo-cross-linked multilayers was demonstrated through experiments with basic solution treatments. Compared to the complete decomposition of uncross-linked multilayers in basic solution, over 74.4% of the covalently cross-linked multilayers were retained under the same conditions, even after a longer duration of basic solution treatment.
基金supported by the National Natural Science Foundation of China(Grant No.20976040)the financial support from Project Supported by Science and Technology Planning Project of Hunan Province,China(No.2009SK3036).
文摘The extraction of cobalt ions from dilute aqueous solutions was investigated by ultrafiltration with the help of poly(acrylic acid)sodium salt(PAASS).Polysulfone and polyethersulfone hollow fiber ultrafiltration membranes were employed in this process.The kinetics of complexation reaction was studied for PAASS with Co^(2+).Results showed that,under a large excess of PAASS,it takes 65,55 and 40 min at pH 5,6 and 7,respectively,to get the equilibrium of complexation.The reaction kinetics can be described by a pseudo-first-order equation.Then,the effects of various parameters on the extraction of Co^(2+)were examined in detail.Results indicated that loading ratio,pH value and low-molecular competitive complexing agent affect significantly cobalt rejection coefficient R.Furthermore,a concentration experiment was carried out at pH 7.With increasing volume concentration factor,membrane flux declines slowly,and R value is always about 1.The concentrated retentate was used further for a decomplexation experiment.The decomplexation ratio of cobalt-PAASS complex reaches as high as 90.1%.After the decomplexation step,a diafiltration experiment was performed at pH 2.5.Cobalt ions can be extracted satisfactorily from the retentate,and a purified PAASS is obtained.
