In this paper, we report on the comprehensive alcohol-/ion-responsive properties of a smart copolymer poly(N- isopropylacry]amide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)). The orthogonal design method ...In this paper, we report on the comprehensive alcohol-/ion-responsive properties of a smart copolymer poly(N- isopropylacry]amide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)). The orthogonal design method is adopted for experimental design. The experimental results show that alcohol can trigger the shrinking and Ba2t can induce the swelling of the P(NIPAM-co-BCAm) copolymer. According to the phase transition tempera- ture (LCST) change results of the copolymer, the influence of variables on the LCST changes weakens in the following order: alcohol concentration 〉 alcohol species 〉 metal ion species 〉 BCAm concentration 〉 ion concentration. The larger the alcohol concentration and the larger the molecular size of alcohols, the lower the LCST value; on the contrary, the more the BCAm content in the copolymer or the larger the BCAm/ion complex stability constant (IgK) or the larger the ion concentration is, the higher the LCST value. For a P(NIPAM-co-BCAm ) copolymer with a fixed BCAm content, a binary function of ion concentration and IgK of BCAm/ion is developed to precisely predict the LCST values of the copolymer in different metal ion solutions. The results provide valuable information for fabricating artificial biomimetic G-protein-gated inwardly rectifying potassium (GIRK) channels that are activated by alcohol and inhibited by Ba2+.展开更多
Colloidal gas aphrons(CGAs) were first defined by Sebba( J.Colloid Interface Sci .,1971,35(4):643) as micro bubbles(25—300?μm).These microbubbles do not coalesce easily and are markedly different from conventional s...Colloidal gas aphrons(CGAs) were first defined by Sebba( J.Colloid Interface Sci .,1971,35(4):643) as micro bubbles(25—300?μm).These microbubbles do not coalesce easily and are markedly different from conventional soap bubbles in their stability and flow properties.CGAs are composed of a gaseous inner core surrounded by a thin surfactant film, which are created by intense stirring of a surfactant solution. CGA dispersion typically contains about 65% gas. CGA suspensions have viscosity similar to water, which make them suitable for pumping without deterioration in quality. Two important considerations in the application of CGA suspensions are: ① their colloidal size, resulting in a large surface area to volume ratio, and ② the existence of a double film of surfactant encapsulating the gas that retards the coalescence of the bubble. CGA suspensions are found very effective for separating hydrophobic organic compounds and heavy metal ions. In this paper, flotation of Cu(Ⅱ) by colloidal gas aphrons has been conducted in order to explore a new method for separating heavy metal ions from dilute solution. The effects of CGA flow rate, amounts of CGA introduced to the system, surfactant concentration on the flotation efficiency have been systematically investigated. The optimum flotation condition is determined. The results show that flotation efficiency at pH=5—6 has an optimum value to CGA flow rate and amount. When pH is greater than 7, the flotation efficiency can be as high as 99% at the optimum condition.展开更多
基金Supported by the National Natural Science Foundation of China(21136006)the Foundation for the Author of National Excellent Doctoral Dissertation of PR China(201163)the National High Technology Research and Development Program(2012AA021403)
文摘In this paper, we report on the comprehensive alcohol-/ion-responsive properties of a smart copolymer poly(N- isopropylacry]amide-co-benzo-18-crown-6-acrylamide) (P(NIPAM-co-BCAm)). The orthogonal design method is adopted for experimental design. The experimental results show that alcohol can trigger the shrinking and Ba2t can induce the swelling of the P(NIPAM-co-BCAm) copolymer. According to the phase transition tempera- ture (LCST) change results of the copolymer, the influence of variables on the LCST changes weakens in the following order: alcohol concentration 〉 alcohol species 〉 metal ion species 〉 BCAm concentration 〉 ion concentration. The larger the alcohol concentration and the larger the molecular size of alcohols, the lower the LCST value; on the contrary, the more the BCAm content in the copolymer or the larger the BCAm/ion complex stability constant (IgK) or the larger the ion concentration is, the higher the LCST value. For a P(NIPAM-co-BCAm ) copolymer with a fixed BCAm content, a binary function of ion concentration and IgK of BCAm/ion is developed to precisely predict the LCST values of the copolymer in different metal ion solutions. The results provide valuable information for fabricating artificial biomimetic G-protein-gated inwardly rectifying potassium (GIRK) channels that are activated by alcohol and inhibited by Ba2+.
文摘Colloidal gas aphrons(CGAs) were first defined by Sebba( J.Colloid Interface Sci .,1971,35(4):643) as micro bubbles(25—300?μm).These microbubbles do not coalesce easily and are markedly different from conventional soap bubbles in their stability and flow properties.CGAs are composed of a gaseous inner core surrounded by a thin surfactant film, which are created by intense stirring of a surfactant solution. CGA dispersion typically contains about 65% gas. CGA suspensions have viscosity similar to water, which make them suitable for pumping without deterioration in quality. Two important considerations in the application of CGA suspensions are: ① their colloidal size, resulting in a large surface area to volume ratio, and ② the existence of a double film of surfactant encapsulating the gas that retards the coalescence of the bubble. CGA suspensions are found very effective for separating hydrophobic organic compounds and heavy metal ions. In this paper, flotation of Cu(Ⅱ) by colloidal gas aphrons has been conducted in order to explore a new method for separating heavy metal ions from dilute solution. The effects of CGA flow rate, amounts of CGA introduced to the system, surfactant concentration on the flotation efficiency have been systematically investigated. The optimum flotation condition is determined. The results show that flotation efficiency at pH=5—6 has an optimum value to CGA flow rate and amount. When pH is greater than 7, the flotation efficiency can be as high as 99% at the optimum condition.