Method for preparing mesoporous silica gel

Abstract

The invention discloses a method for preparing mesoporous silica gel. The method comprises the following steps: (1) adding a cellulose raw material into an inorganic acid solution with the mass concentration of 15% to 75%, and carrying out uniform stirring and mixing; (2) uniformly mixing a sodium silicate solution with the silicon dioxide mass concentration of 10% to 30% with the material obtained in the step (1) so as to enable the pH of the material to reach 1 to 10; (3) carrying out aging gelatination on the material obtained in the step (2); and (4) washing the material obtained in the step (3) until the material is neutral, then, carrying out filtrating and baking, and carrying out activation roasting in an air atmosphere, thereby obtaining the mesoporous silica gel. According to the method disclosed by the invention, cellulose is introduced during the preparation of the silica gel as a pore forming raw material, is environmentally friendly and belongs to renewable resources, and the raw materials are rich and cheap, so that the raw-material cost is reduced greatly compared with that of synthesis methods employing petrochemicals as template agents.

Description

technical field [0001] The invention specifically relates to a preparation method of mesoporous silica gel. Background technique [0002] Silica gel has a special pore structure, large specific surface area and excellent thermal stability, and is widely used in various industrial fields such as adsorbents, desiccants, chromatographic column packings and catalyst carriers. The existing technology mainly adopts further steaming or alkali leaching on the aging silica gel for pore expansion treatment to obtain medium or macroporous silica gel products. This method is cumbersome in process, long in cycle and high in cost. There are also relevant literature reports on the method of preparing ordered mesoporous silica using surfactants as templates. The surfactant templates added in the preparation process mainly include, such as: hexadecyltrimethylammonium Dialkyl sodium sulfate, P123, F127, etc., but the templating agent is expensive and the preparation cost is high, so it is no...

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Problems solved by technology

The existing technology mainly adopts further steaming or alkali leaching on the aging silica gel for pore expansion treatment to obtain medium or macroporous silica gel products. This method is cumbersome in process, long in cycle and high in cost.

There are also relevant literature reports on the method of preparing ordered mesoporous silica using surfactants as templates. The surfactant templates added in the preparation process mainly include, such as: hexadecyltrimethylammonium Dialkyl sodium sulfate, P123, F127, etc., but the template agent is expensive and the preparation cost is high, so it is not widely used in mass production at present

There are also relevant reports that azeotropic distillation technology is used to select organic solvents with relatively high boiling points, such as C5-C6 alcohols, such as 3-methyl butanol, n-pentyl alcohol, etc., to obtain silica gel with large pore volume and high specific surface area. product, but its technology is complex and the preparation process is cumbersome

CN1792790 discloses a method of controlling the pore size of silica gel by first roasting and then acid treatment. This method uses sulfate to swell during roasting to form pores, and then needs to be washed with strong acid again to dissolve the sulfate. The steps are relatively cumbersome.

CN102002120A discloses a method for preparing silica gel with large pore volume and large specific surface area by using a specific surface control agent (ethylene glycol, ethyl acetate, glycerol, acetone, or one or more of trichloroethane) to obtain a specific surface area. Surface area 400-600m 2 / g of silica gel, the pore-forming agent is mainly chemical products, not only expensive, but also non-renewable

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