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
Triton X-114, an non-ionic surfactant, was modified with the affinity ligand of trypsin,p-aminobenzamidine (PAB) and the affinity surfactant (PAB-TX) was synthesized.Then, the affinity surfactant was used to prepare a...Triton X-114, an non-ionic surfactant, was modified with the affinity ligand of trypsin,p-aminobenzamidine (PAB) and the affinity surfactant (PAB-TX) was synthesized.Then, the affinity surfactant was used to prepare affinity-based colloidal gas aphrons (CGA).The stability of the affinity CGA was investigated at different temperatures and compared with that of the CGA prepared from Triton X-114.Compared with the CGA from Triton X-114, the affinity CGA showed high selective adsorption property for trypsin.In the separation of a protein mixture,recovery yield higher than 74% were achieved for trypsin and the separation factor reached over 1.5.The results showed that the affinity CGA possessed promising selectivity for separating trypsin from a protein mixture.展开更多
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.
文摘Triton X-114, an non-ionic surfactant, was modified with the affinity ligand of trypsin,p-aminobenzamidine (PAB) and the affinity surfactant (PAB-TX) was synthesized.Then, the affinity surfactant was used to prepare affinity-based colloidal gas aphrons (CGA).The stability of the affinity CGA was investigated at different temperatures and compared with that of the CGA prepared from Triton X-114.Compared with the CGA from Triton X-114, the affinity CGA showed high selective adsorption property for trypsin.In the separation of a protein mixture,recovery yield higher than 74% were achieved for trypsin and the separation factor reached over 1.5.The results showed that the affinity CGA possessed promising selectivity for separating trypsin from a protein mixture.
