A MOF-74 analog derived from non-DOBDC linkers, Cu（II）-MOF-74-L^1, was synthesized and characterized. Based on this, directionanl functionalizations of the hexagonal pore were introduced through well-designed pre-in...A MOF-74 analog derived from non-DOBDC linkers, Cu（II）-MOF-74-L^1, was synthesized and characterized. Based on this, directionanl functionalizations of the hexagonal pore were introduced through well-designed pre-installation of ligands. By this strategy, two MOF-74 analogs with hydrophobic and hydrophilic surfaces of pore had been achieved by equiping with CI or OH groups respectively and proved with excellent catalysis and luminescent sensing properties. Herein, the synthetic strategy and functional regulation were reported toward the development of functional MOF-74 materials.展开更多
The rational design of nano-carriers is critical for modem enzyme immobilization for advanced biocatalysis. Herein, we report the synthesis of octadecylalkyl- modified mesoporous-silica nanoparticles （C18-MSNs） with...The rational design of nano-carriers is critical for modem enzyme immobilization for advanced biocatalysis. Herein, we report the synthesis of octadecylalkyl- modified mesoporous-silica nanoparticles （C18-MSNs） with a high C18 content （-19 wt.%） and tunable pore sizes （1.6--13 nm）. It is demonstrated that the increased hydrophobic content and a tailored pore size （slightly larger than the size of lipase） are responsible for the high performance of immobilized lipase. The optimized C18-MSNs exhibit a loading capacity of 711 mg/g and a specific activity 5.23 times higher than that of the free enzyme. Additionally, 93% of the initial activity is retained after reuse five times, which is better than the best performance reported to date. Our findings pave the way for the robust immobilization of lipase for biocatalytic applications.展开更多
In this study, poly(vinilydene fluoride-co-hexafluoropropylene)(PVDF-HFP) was used for preparation of hydrophobic membranes using non-solvent induced phase inversion(NIPS) technique. PVDF-HFP copolymer with concentrat...In this study, poly(vinilydene fluoride-co-hexafluoropropylene)(PVDF-HFP) was used for preparation of hydrophobic membranes using non-solvent induced phase inversion(NIPS) technique. PVDF-HFP copolymer with concentrations of 10 wt% and 12 wt% was prepared to investigate the effect of polymer concentration on pore structure,morphology, hydrophobicity and performance of prepared membranes. Besides, the use of two coagulation baths with the effects of parameters such as coagulant time, polymer type and concentration, and the amount of nonsolvent were studied. The performance of prepared membranes was evaluated based on the permeability and selectivity of oxygen and nitrogen from a gas mixture of nitrogen/oxygen under operating conditions of feed flow rate(1–5 L·min-1), inlet pressure to membrane module(0.1–0.5 MPa) and temperatures between 25 and 45 °C. The results showed that the use of two coagulation baths with different compositions of distillated water and isopropanol,coagulant time, polymer type and concentration, and the amount of non-solvent additive have the most effect on pore structure, morphology, thickness, roughness and crystallinity of fabricated membranes. Porosity ranges for the three fabricated membranes were determined, where the maximum porosity was 73.889% and the minimum value was 56.837%. Also, the maximum and minimum average thicknesses of membrane were 320.85 μm and115 μm. Besides, the values of 4.7504 × 10-7 mol· m-2· s-1· Pa-1, 0.525 and 902.126 nm were achieved for maximum oxygen permeance, O2/N2 selectivity and roughness, respectively.展开更多
提出了一种新型的基于半透膜被动采样技术的微萃取方法(semi-permeable membrane based micro-extraction,SPM-ME),并以菲为模型污染物,测试了SPM-ME用于测定土壤间隙水中自由溶解态憎水性有机污染物的可行性。结果表明,菲在该SPE-ME装...提出了一种新型的基于半透膜被动采样技术的微萃取方法(semi-permeable membrane based micro-extraction,SPM-ME),并以菲为模型污染物,测试了SPM-ME用于测定土壤间隙水中自由溶解态憎水性有机污染物的可行性。结果表明,菲在该SPE-ME装置与水相间的平衡可在6h内达到,并且随着装置中三油酸甘油酯含量的增加,单元SPE-ME对于菲的富集系数也相应增加。该装置对土壤间隙水中菲的富集在10d内能达到平衡,整个过程主要受菲从土壤向间隙水的传质控制。该装置测得间隙水中菲的浓度与实际测得间隙水浓度十分吻合,而由传统的相平衡分配法计算所得间隙水浓度则高出实测值4～5倍。同时,该装置对体系中污染物的耗竭小于体系中污染物总量的1%。因此,SPE-ME是一种准确、有效、非耗竭式的微萃取技术。展开更多
文摘A MOF-74 analog derived from non-DOBDC linkers, Cu（II）-MOF-74-L^1, was synthesized and characterized. Based on this, directionanl functionalizations of the hexagonal pore were introduced through well-designed pre-installation of ligands. By this strategy, two MOF-74 analogs with hydrophobic and hydrophilic surfaces of pore had been achieved by equiping with CI or OH groups respectively and proved with excellent catalysis and luminescent sensing properties. Herein, the synthetic strategy and functional regulation were reported toward the development of functional MOF-74 materials.
文摘The rational design of nano-carriers is critical for modem enzyme immobilization for advanced biocatalysis. Herein, we report the synthesis of octadecylalkyl- modified mesoporous-silica nanoparticles （C18-MSNs） with a high C18 content （-19 wt.%） and tunable pore sizes （1.6--13 nm）. It is demonstrated that the increased hydrophobic content and a tailored pore size （slightly larger than the size of lipase） are responsible for the high performance of immobilized lipase. The optimized C18-MSNs exhibit a loading capacity of 711 mg/g and a specific activity 5.23 times higher than that of the free enzyme. Additionally, 93% of the initial activity is retained after reuse five times, which is better than the best performance reported to date. Our findings pave the way for the robust immobilization of lipase for biocatalytic applications.
文摘In this study, poly(vinilydene fluoride-co-hexafluoropropylene)(PVDF-HFP) was used for preparation of hydrophobic membranes using non-solvent induced phase inversion(NIPS) technique. PVDF-HFP copolymer with concentrations of 10 wt% and 12 wt% was prepared to investigate the effect of polymer concentration on pore structure,morphology, hydrophobicity and performance of prepared membranes. Besides, the use of two coagulation baths with the effects of parameters such as coagulant time, polymer type and concentration, and the amount of nonsolvent were studied. The performance of prepared membranes was evaluated based on the permeability and selectivity of oxygen and nitrogen from a gas mixture of nitrogen/oxygen under operating conditions of feed flow rate(1–5 L·min-1), inlet pressure to membrane module(0.1–0.5 MPa) and temperatures between 25 and 45 °C. The results showed that the use of two coagulation baths with different compositions of distillated water and isopropanol,coagulant time, polymer type and concentration, and the amount of non-solvent additive have the most effect on pore structure, morphology, thickness, roughness and crystallinity of fabricated membranes. Porosity ranges for the three fabricated membranes were determined, where the maximum porosity was 73.889% and the minimum value was 56.837%. Also, the maximum and minimum average thicknesses of membrane were 320.85 μm and115 μm. Besides, the values of 4.7504 × 10-7 mol· m-2· s-1· Pa-1, 0.525 and 902.126 nm were achieved for maximum oxygen permeance, O2/N2 selectivity and roughness, respectively.
文摘提出了一种新型的基于半透膜被动采样技术的微萃取方法(semi-permeable membrane based micro-extraction,SPM-ME),并以菲为模型污染物,测试了SPM-ME用于测定土壤间隙水中自由溶解态憎水性有机污染物的可行性。结果表明,菲在该SPE-ME装置与水相间的平衡可在6h内达到,并且随着装置中三油酸甘油酯含量的增加,单元SPE-ME对于菲的富集系数也相应增加。该装置对土壤间隙水中菲的富集在10d内能达到平衡,整个过程主要受菲从土壤向间隙水的传质控制。该装置测得间隙水中菲的浓度与实际测得间隙水浓度十分吻合,而由传统的相平衡分配法计算所得间隙水浓度则高出实测值4～5倍。同时,该装置对体系中污染物的耗竭小于体系中污染物总量的1%。因此,SPE-ME是一种准确、有效、非耗竭式的微萃取技术。
