The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the M...The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn 2+ and H_2O_2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H_2O_2. When the amount of the immobilized H_2O_2 is sufficient, the microemulsion-based gels containing MnP could be used many times.展开更多
Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techni...Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.展开更多
[Objectives] To study the rheology and release kinetics of Chuanqi ophthalmic microemulsion in situ gel,so as to provide references for its future study and development. [Methods]The fluid properties and linear viscoe...[Objectives] To study the rheology and release kinetics of Chuanqi ophthalmic microemulsion in situ gel,so as to provide references for its future study and development. [Methods]The fluid properties and linear viscoelastic regions of this preparation were investigated by MCR 102 rheometer. The release kinetics of Chuanqi ophthalmic microemulsion in situ gel was evaluated by modified Franz diffusion cell method,the ligustrazine and ligustilide were selected as the indictors,and semi-permeable membrane was used as a barrier,sampling time point was 0. 5,1,2,4,6,and 8 h respectively. [Results]Chuanqi ophthalmic microemulsion in situ gel was a pseudoplastic fluid and it had a linear viscoelastic region. Taking the shear stress as the indicator,the linear viscoelastic region was 0-302. 74 Pa; taking the strain as the indicator,the linear viscoelastic region was 0-7. 45%. At the critical point,the storage modulus( G') = the loss modulus( G″) =2 976. 60 Pa,critical shear stress was 302. 74 Pa and critical strain was 7. 45%. The average cumulative release of ligustrazine of 6 samples within 8 h was 33. 71 μg,the average cumulative release rate reached 90. 08%,and the release kinetics followed Higuchi equation. The average cumulative release of ligustilide of 6 samples within 8 h was 68. 46 μg,the average cumulative release rate reached 84. 32%,and the release kinetics followed the zero-order kinetics equation. [Conclusions] Chuanqi ophthalmic microemulsion in situ gel has excellent viscoelasticity and its strain is reversible in a certain range. The release kinetics of ligustrazine is the result from synergistic effect of its physicochemical properties and matrix skeleton,while the release kinetics of ligustilide is mainly affected by its physicochemical properties.展开更多
Based on an unusual reversible sol-gel transition phenomenon. a novel method for the fabrication of a lipase electrode was developed. The response characteristics of the biosensor was studied by potentiometric techniq...Based on an unusual reversible sol-gel transition phenomenon. a novel method for the fabrication of a lipase electrode was developed. The response characteristics of the biosensor was studied by potentiometric technique using olive oil as substrate. After optimization, the lipase electrode demonstrated high activity and good stability.展开更多
Gel polymer electrolytes(GPEs)have attracted extensive attention in lithium-ion batteries due to their high security and excellent electrochemical performance.However,their inferior Li-ion transference number,low room...Gel polymer electrolytes(GPEs)have attracted extensive attention in lithium-ion batteries due to their high security and excellent electrochemical performance.However,their inferior Li-ion transference number,low room-temperature ionic conductivity,and poor long cycle stability raise challenges in practical applications.Herein,a flexible poly(vinylidene fluoride-cohexafluoropropylene)-butanedinitrile(PVDF-HFP-SN)-based GPE(PSGPE)is synthesized successfully by a general immersion precipitation method.The resultant PSGPEs have numerous connecting pores to ensure sufficient space for liquid electrolytes.Moreover,the reduced crystallinity of PVDF-HFP and the high polarity of SN can reduce the energy barrier of Li-ions shuttling between pores.The synergistic effect possesses a high ionic conductivity of 1.35 mS·cm^(-1)at room temperature with a high Li-ion transference number of 0.69.The PVDF-HFP-SN-based GPE is applied in a LiFePO_(4)/graphite battery,which can realize stable cycling performance for 350 cycles and good rate performance at room temperature.These results demonstrate that the novel PSGPE possesses advantage in simplified production process,which can improve the practicability of gel polymer lithium-ion batteries.展开更多
文摘The immobilized technique of manganese peroxidase(MnP) in gelatin-containing microemulsion-based gels and the effects of storage time and reuse times on its catalytic activity were studied. The results show that the MnP immobilized together with Mn 2+ and H_2O_2 could effectively oxidize syringaldazine in n-heptane. The immobilized MnP still had a high catalytic activity after one-month storage under a freezing condition. The reuse times have a relation to the amount of the immobilized H_2O_2. When the amount of the immobilized H_2O_2 is sufficient, the microemulsion-based gels containing MnP could be used many times.
基金Supported by the Natural Science Foundation of Shandong Province in China(No.Y2003B01).
文摘Introduction The formation of gelatin-containing mieroemulsionbased gels（MBGs） was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.
基金Supported by Project of National Natural Science Foundation(81373977)
文摘[Objectives] To study the rheology and release kinetics of Chuanqi ophthalmic microemulsion in situ gel,so as to provide references for its future study and development. [Methods]The fluid properties and linear viscoelastic regions of this preparation were investigated by MCR 102 rheometer. The release kinetics of Chuanqi ophthalmic microemulsion in situ gel was evaluated by modified Franz diffusion cell method,the ligustrazine and ligustilide were selected as the indictors,and semi-permeable membrane was used as a barrier,sampling time point was 0. 5,1,2,4,6,and 8 h respectively. [Results]Chuanqi ophthalmic microemulsion in situ gel was a pseudoplastic fluid and it had a linear viscoelastic region. Taking the shear stress as the indicator,the linear viscoelastic region was 0-302. 74 Pa; taking the strain as the indicator,the linear viscoelastic region was 0-7. 45%. At the critical point,the storage modulus( G') = the loss modulus( G″) =2 976. 60 Pa,critical shear stress was 302. 74 Pa and critical strain was 7. 45%. The average cumulative release of ligustrazine of 6 samples within 8 h was 33. 71 μg,the average cumulative release rate reached 90. 08%,and the release kinetics followed Higuchi equation. The average cumulative release of ligustilide of 6 samples within 8 h was 68. 46 μg,the average cumulative release rate reached 84. 32%,and the release kinetics followed the zero-order kinetics equation. [Conclusions] Chuanqi ophthalmic microemulsion in situ gel has excellent viscoelasticity and its strain is reversible in a certain range. The release kinetics of ligustrazine is the result from synergistic effect of its physicochemical properties and matrix skeleton,while the release kinetics of ligustilide is mainly affected by its physicochemical properties.
文摘Based on an unusual reversible sol-gel transition phenomenon. a novel method for the fabrication of a lipase electrode was developed. The response characteristics of the biosensor was studied by potentiometric technique using olive oil as substrate. After optimization, the lipase electrode demonstrated high activity and good stability.
基金This work was funded by Huaneng Clean Energy Research Institute Found Project(No.TE-22-CERI01).
文摘Gel polymer electrolytes(GPEs)have attracted extensive attention in lithium-ion batteries due to their high security and excellent electrochemical performance.However,their inferior Li-ion transference number,low room-temperature ionic conductivity,and poor long cycle stability raise challenges in practical applications.Herein,a flexible poly(vinylidene fluoride-cohexafluoropropylene)-butanedinitrile(PVDF-HFP-SN)-based GPE(PSGPE)is synthesized successfully by a general immersion precipitation method.The resultant PSGPEs have numerous connecting pores to ensure sufficient space for liquid electrolytes.Moreover,the reduced crystallinity of PVDF-HFP and the high polarity of SN can reduce the energy barrier of Li-ions shuttling between pores.The synergistic effect possesses a high ionic conductivity of 1.35 mS·cm^(-1)at room temperature with a high Li-ion transference number of 0.69.The PVDF-HFP-SN-based GPE is applied in a LiFePO_(4)/graphite battery,which can realize stable cycling performance for 350 cycles and good rate performance at room temperature.These results demonstrate that the novel PSGPE possesses advantage in simplified production process,which can improve the practicability of gel polymer lithium-ion batteries.
