Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalyti...Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalytic reactions.Despite the fact that solubility and diffusion rates of oxygen in many liquids(such as perfluorocarbon)are much higher than in water,multiphase reactions with a second liquid phase are still difficult to conduct,because the interaction efficiency between immiscible phases is extremely low.Herein,we report an efficient triphase biocatalytic system using oil core-silica shell oxygen nanocarriers.Such design offers the biocatalytic system an extremely large water-solid-oil triphase interfacial area and a short path required for oxygen diffusion.Moreover,the silica shell stabilizes the oil nanodroplets in water and prevents their aggregation.Using oxygen-dependent oxidase enzymatic reaction as an example,we demonstrate this efficient biocatalytic system for the oxidation of glucose,choline,lactate,and sucrose by substituting their corresponding oxidase counterparts.A rate enhancement by a factor of 10-30 is observed when the oxygen nanocarriers are introduced into reaction system.This strategy offers the opportunity to enhance the efficiency of other gaseous reactants involved in multiphase catalytic reactions.展开更多
Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved...Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved polymerization-induced colloid aggregation （PICA） method using urea-formaldehyde polymers as the templates. The agglomeration of the functionalized silica core was avoided by the surface modification through reflux with ureidopropyltrimethoxysilane in the neutral ethanol solution at 80 ~C, and the secondary nucleation of the silica nanoparticles during the preparation process could also be inhibited via the optimization of the reaction conditions, such as pH, temperature, colloidal silica sol concentration and the reaction time. The controllable shell thickness and pore size of the synthesized monodisperse CSSMs were successfully obtained by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The C18-modified CSSMs with different pore sizes were used to separate small solutes and proteins. The higher efficient separation and relatively low back pressure of the synthesized core-shefi column demonstrate that the CSSMs have a great ootential aoolication for fast HPLC展开更多
基金the National Key R&D Program of China(No.2019YFA0709200)the National Natural Science Foundation of China(Nos.21988102,51772198,21975171).
文摘Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalytic reactions.Despite the fact that solubility and diffusion rates of oxygen in many liquids(such as perfluorocarbon)are much higher than in water,multiphase reactions with a second liquid phase are still difficult to conduct,because the interaction efficiency between immiscible phases is extremely low.Herein,we report an efficient triphase biocatalytic system using oil core-silica shell oxygen nanocarriers.Such design offers the biocatalytic system an extremely large water-solid-oil triphase interfacial area and a short path required for oxygen diffusion.Moreover,the silica shell stabilizes the oil nanodroplets in water and prevents their aggregation.Using oxygen-dependent oxidase enzymatic reaction as an example,we demonstrate this efficient biocatalytic system for the oxidation of glucose,choline,lactate,and sucrose by substituting their corresponding oxidase counterparts.A rate enhancement by a factor of 10-30 is observed when the oxygen nanocarriers are introduced into reaction system.This strategy offers the opportunity to enhance the efficiency of other gaseous reactants involved in multiphase catalytic reactions.
基金supported by the National Natural Science Foundation of China(Nos.21545007,21605122)the Foundation of Key Laboratory in Shaanxi Province(Nos. 2010JS103, 11JS097, 15JS115)
文摘Superficially porous core-shell silica microspheres （CSSMs） have been a great success for the fast separation of small molecules and proteins in recent years. In this paper, the CSSMs were synthesized by an improved polymerization-induced colloid aggregation （PICA） method using urea-formaldehyde polymers as the templates. The agglomeration of the functionalized silica core was avoided by the surface modification through reflux with ureidopropyltrimethoxysilane in the neutral ethanol solution at 80 ~C, and the secondary nucleation of the silica nanoparticles during the preparation process could also be inhibited via the optimization of the reaction conditions, such as pH, temperature, colloidal silica sol concentration and the reaction time. The controllable shell thickness and pore size of the synthesized monodisperse CSSMs were successfully obtained by adjusting the weight ratio of silica core/colloidal silica sol and the particle size of colloidal silica sol, respectively. The C18-modified CSSMs with different pore sizes were used to separate small solutes and proteins. The higher efficient separation and relatively low back pressure of the synthesized core-shefi column demonstrate that the CSSMs have a great ootential aoolication for fast HPLC
