It has been theoretically predicted that under conditions leading to Gibbs-Donnan equilibrium in case when size of one compartment is very different from another (as in system “membrane vesicle/liposomes—incubation ...It has been theoretically predicted that under conditions leading to Gibbs-Donnan equilibrium in case when size of one compartment is very different from another (as in system “membrane vesicle/liposomes—incubation medium”) stable transmembrane potential can be formed, which value is sufficient to fit requirement of real transmembrane potential. Four partial cases were considered with different location and charge of impermeable ion and it was concluded that locations of impermeable ions in medium provide stable transmembrane potential with sufficient value of 60 - 70 mV. Potential-sensitive probe, such as DiOC6(3) and oxonol VI, were used to confirm the calculated potential. According to the change in fluorescence level and emission/excitation shift, a stable and relatively high transmembrane potential can be formed if salt of impermeable ion is located in incubation medium. Impermeable cations and anions may be used to create positive and negative transmembrane potential respectively.展开更多
In the present study a novel technique was proposed to prepare a polymer-supported hydrated ferric oxide (D201-HFO) based on Donnan membrane effect by using a strongly basic anion exchanger D201 as the host material a...In the present study a novel technique was proposed to prepare a polymer-supported hydrated ferric oxide (D201-HFO) based on Donnan membrane effect by using a strongly basic anion exchanger D201 as the host material and FeCl3-HCl-NaCl solution as the reaction environment. D201-HFO was found to exhibit higher capacity for arsenic removal than a commercial sorbent Purolite ArsenX. Furthermore, it presents favorable adsorption selectivity for arsenic removal from aqueous solution, as well as satis- factory kinetics. Fixed-bed column experiments showed that arsenic sorption on D201-HFO could re- sult in concentration of this toxic metalloid element below 10 μg/L, which was the new maximum con- centration limit set recently by the European Commission and imposed by the US EPA and China. Also, the spent D201-HFO is amenable to efficient regeneration by NaOH-NaCl solution.展开更多
文摘It has been theoretically predicted that under conditions leading to Gibbs-Donnan equilibrium in case when size of one compartment is very different from another (as in system “membrane vesicle/liposomes—incubation medium”) stable transmembrane potential can be formed, which value is sufficient to fit requirement of real transmembrane potential. Four partial cases were considered with different location and charge of impermeable ion and it was concluded that locations of impermeable ions in medium provide stable transmembrane potential with sufficient value of 60 - 70 mV. Potential-sensitive probe, such as DiOC6(3) and oxonol VI, were used to confirm the calculated potential. According to the change in fluorescence level and emission/excitation shift, a stable and relatively high transmembrane potential can be formed if salt of impermeable ion is located in incubation medium. Impermeable cations and anions may be used to create positive and negative transmembrane potential respectively.
基金Partially supported by the National Natural Science Foundation of China (Grant No. 20504012)the Natural Science Foundation of Jiangsu Province (Grant No. BK2006129)the Scientific Research Foundation of Graduate School of Nanjing University (Grant No. 2006CL11)
文摘In the present study a novel technique was proposed to prepare a polymer-supported hydrated ferric oxide (D201-HFO) based on Donnan membrane effect by using a strongly basic anion exchanger D201 as the host material and FeCl3-HCl-NaCl solution as the reaction environment. D201-HFO was found to exhibit higher capacity for arsenic removal than a commercial sorbent Purolite ArsenX. Furthermore, it presents favorable adsorption selectivity for arsenic removal from aqueous solution, as well as satis- factory kinetics. Fixed-bed column experiments showed that arsenic sorption on D201-HFO could re- sult in concentration of this toxic metalloid element below 10 μg/L, which was the new maximum con- centration limit set recently by the European Commission and imposed by the US EPA and China. Also, the spent D201-HFO is amenable to efficient regeneration by NaOH-NaCl solution.
