Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol wit...Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol with tert-butanol than conventional H-AlMCM-48 materials.展开更多
A novel Pd（ll） organometal catalyst with three-dimensional （3D） cage-like la3d cubic mesoporous structure and high surface area was prepared. In comparison with the corresponding catalyst with two-dimensional （2D...A novel Pd（ll） organometal catalyst with three-dimensional （3D） cage-like la3d cubic mesoporous structure and high surface area was prepared. In comparison with the corresponding catalyst with two-dimensional （2D） P6mm hexagonal mesoporous structure, the as-prepared catalyst exhibited higher activities in the water-medium Suzuki coupling reactions owing to the diminished diffusion limit. It showed comparable efficiencies with the Pd（PPh3）2C12 homogeneous catalyst and could be easily recycled and reused for five times without significant loss of activity.展开更多
Mesoporous silica nanoparticles （MSNs） are promising for drug delivery and other biomedical applications owing to their excellent chemical stability and biocompatibility. For these applications, a hollow morphology ...Mesoporous silica nanoparticles （MSNs） are promising for drug delivery and other biomedical applications owing to their excellent chemical stability and biocompatibility. For these applications, a hollow morphology with thin shell and open mesopores is preferred for MSNs in order to maximize the loading capacity of drugs. Herein we report a novel and direct synthesis of such an ideal drug delivery system in a dilute and alkaline solution of benzylcetyl- dimethylammonium chloride and diethylene glycol hexadecyl ether. The mixed surfactants can guide the formation of MSNs with cubic Ia3d mesostructure, and at a concentration of sodium hydroxide between 9.8 and 13.5 mM, hollow MSNs with uniform sizes of 90-120 nm and a single-unit-cell-thick shell are formed. A mechanism for the formation of the hollow Ia3d MSNs, designated as MMT-2, is proposed based on in situ small-angle X-ray scattering measurements and other analyses. MMT-2 exhibits much higher loading capacity of ibuprofen and degrades faster in simulated body fluid and phosphate buffered saline than non-hollow MSNs. The degradation of MMT-2 can be significantly retarded by modification with polyethylene glycol. More interestingly, the degradation of MMT-2 involves fragmentation instead of void formation, a phenomenon beneficial for their elimination. The results demonstrate the uniqueness of the hollow Ia3d MSNs and the great potential of the material for drug delivery and biomedical applications.展开更多
基金We thank financial support by the National Natural Science Foundation of China(grant 29973001).
文摘Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol with tert-butanol than conventional H-AlMCM-48 materials.
文摘A novel Pd（ll） organometal catalyst with three-dimensional （3D） cage-like la3d cubic mesoporous structure and high surface area was prepared. In comparison with the corresponding catalyst with two-dimensional （2D） P6mm hexagonal mesoporous structure, the as-prepared catalyst exhibited higher activities in the water-medium Suzuki coupling reactions owing to the diminished diffusion limit. It showed comparable efficiencies with the Pd（PPh3）2C12 homogeneous catalyst and could be easily recycled and reused for five times without significant loss of activity.
文摘Mesoporous silica nanoparticles （MSNs） are promising for drug delivery and other biomedical applications owing to their excellent chemical stability and biocompatibility. For these applications, a hollow morphology with thin shell and open mesopores is preferred for MSNs in order to maximize the loading capacity of drugs. Herein we report a novel and direct synthesis of such an ideal drug delivery system in a dilute and alkaline solution of benzylcetyl- dimethylammonium chloride and diethylene glycol hexadecyl ether. The mixed surfactants can guide the formation of MSNs with cubic Ia3d mesostructure, and at a concentration of sodium hydroxide between 9.8 and 13.5 mM, hollow MSNs with uniform sizes of 90-120 nm and a single-unit-cell-thick shell are formed. A mechanism for the formation of the hollow Ia3d MSNs, designated as MMT-2, is proposed based on in situ small-angle X-ray scattering measurements and other analyses. MMT-2 exhibits much higher loading capacity of ibuprofen and degrades faster in simulated body fluid and phosphate buffered saline than non-hollow MSNs. The degradation of MMT-2 can be significantly retarded by modification with polyethylene glycol. More interestingly, the degradation of MMT-2 involves fragmentation instead of void formation, a phenomenon beneficial for their elimination. The results demonstrate the uniqueness of the hollow Ia3d MSNs and the great potential of the material for drug delivery and biomedical applications.
