Preparation method of transparent mesoporous silica-alumina gel monolith

Abstract

The invention relates to a preparation method of a transparent mesoporous silica-alumina gel monolith, and particularly relates to a fast preparation method of a large-size flawless optical transparent mesoporous silica-alumina gel monolith with the mole ratio of Si/Al components more than or equal to 5, belonging to the technical field of inorganic porous materials. The fast preparation method regulates the mole ratio of Si/Al of a synthetic gel by introducing Al atoms, also strictly controls the range of the mole ratio of Si/H2O of a synthetic system and ensures that a prepared wet silica-alumina gel can complete direct open transformation to a dried gel without generating flaws at higher temperature by being correlated with a system gelation method. The fast preparation method disclosed by the invention has the advantages of short synthesizing period, simple operation step, easiness for control, regular product shape, controllable size, good heat stability and transparence, wide application value in the field of development of novel optical devices, specific area of 340-800 m<2>/g of the mesoporous silica-alumina gel monolith obtained after removing a surface active agent template through roasting, pore volume of 0.3--/5 cm<3>/g, pore diameter of 2-4 nanometers, and wide application prospects on the aspects of catalyzation and separation.

Description

technical field [0001] The invention discloses a method for preparing a transparent mesoporous silica-alumina gel monolith, which belongs to the technical field of inorganic porous materials, and specifically relates to a large-sized, crack-free and optically transparent mesoporous silica-alumina with a component Si / Al molar ratio ≥ 5 Rapid preparation method of gel monolith. Background technique [0002] The transparent mesoporous gel monolith formed by surfactant as a template has high light transmittance, low external area and adjustable pore structure, which can make dye molecules, photosensitive molecules, semiconductor particles or Guest molecules such as conductive nanowires can be intercalated at a high concentration without mutual aggregation between molecules, so they have broad application prospects in the development of new optical devices. [0003] However, most of the transparent mesoporous gel monoliths reported at home and abroad are mainly composed of elect...

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Problems solved by technology

[0004] The current published document Micro.Meso.Mater., 2011,138,51 involves the preparation of a mesoporous silica-alumina gel, but it needs to introduce long-chain alkanes to form a microemulsion phase during its synthesis, and the final mesoporous silica-alumina gel The gel monolith is in a translucent or opaque state, which has lost the possibility of being applied in the optical field. At the same time, the drying operation of the prepared wet gel needs to be carried out in an airtight container, and the specific temperature of drying is not given; while the open literature Micro.Meso.Mater., 2007,99,47 also involves the preparation of a transparent mesoporous silica-alumina gel monolith with a Si / Al molar ratio of 10-80, but vacuum operation is required to remove the Ethanol, and the slow drying process at room temperature is used, which takes a long time and has low production efficiency, which is not conducive to industrial mass production