Method for preparing noble metal hollow micro capsule

Abstract

The present invention relates to the preparation process of a kind of hollow noble metal microcapsule. After mesoporous silica microball as template is amino group modified, nano noble metal particle is filled into the microball hole canal and one layer of polyelectrolyte is adsorbed to the surface, and silica is finally leached out through treatment in alkali solution condition to prepare the hollow noble metal microcapsule. Said process is simple, has adjustable shell material and is suitable for the preparation of most kinds of functional microcapsule. The microcapsule product has fine appearance and excellent performance, and may find its wide application in different fields, such as medicine preparation, catalyzing, electrochemistry, etc.

Description

technical field [0001] The invention relates to a method for preparing noble metal hollow microcapsules by using mesoporous silicon oxide microspheres as a template. Background technique [0002] Hollow microcapsules with different shell components such as metal oxides, sulfides and noble metals have great potential in catalytic, optical, electrochemical and other functions due to their unique large cavity volume, functional shell components and high specific surface area. There are broad application prospects in the field of materials, and it has become one of the main research hotspots in recent years. [0003] At present, the synthesis of hollow microcapsules mainly relies on spray drying (P.J.Bruinsma, A.Y.Kim, J.Liu, S.Baskaran, Chem.Mater., 1997,9,2507), emulsion / phase separation (H.Lin, Y. Cheng, C.Mou, Chem.Mater., 1998, 10, 3772) and sacrificial nuclear technology (L.Dlhne, S.Leporatti,; E.Donath, H.Mhwald, J.Am.Chem.Soc., 2001, 123, 5431; S.M.Marinakos, J.P.Nov...

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Problems solved by technology

The first method is to prepare the precursor species (such as easily hydrolyzed metal alkoxide, etc.) that constitute the hollow microcapsule shell components into an aqueous solution, and form atomized droplets through a nozzle. Since the operation is generally carried out in a dry atmosphere, the formation of The solvent in the droplet evaporates rapidly, which promotes the rapid hydrolysis of the hard-to-volatile precursor species on the surface of the droplet to form the shell structure of the hollow microcapsule. This method can quickly and conveniently synthesize the hollow microcapsule, but it involves high pressure and high energy. The use of expensive spray equipment and the provision of a strictly dry atmosphere create safety and economical issues during the preparation process; the second method is to hydrolyze the components that form the microcapsule shell at the oil / water interface to form hollow microcapsules. Capsule shell structure, this method is suitable for the synthesis of most shell component microcapsules, but the operation process is complicated and the repeatability is poor, and the size of the obtained microcapsules is strictly limited by the size of the droplet, and it is difficult to obtain the particle size distribution uniform microcapsules

The third method uses removable microspheres (such as polymers and silica microspheres) as templates, and then deposits the desired species layer by layer on the surface of the template spheres to form nuclei through surface chemical reactions or electrostatic physical adsorption- shell structure, and finally the template is removed by roasting or chemical corrosion to obtain hollow microcapsules. A shell with a certain strength often requires multi-layer deposition operations, and the steps are relatively cumbersome, which is not suitable for large-scale synthesis

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