Silica aerogel and normal pressure drying preparation method and application thereof

A silicon dioxide, atmospheric drying technology, applied in chemical instruments and methods, inorganic chemistry, silicon compounds, etc., can solve the problems of cumbersome operation, increased cost, long preparation period, etc.

Active Publication Date: 2018-12-04
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the commonly used methods for removing ions are: (1) use ion exchange resin to treat the silicon source, and adjust the pH value of the silicon source from alkaline to acidic during the treatment process. Obtaining high-performance aerogels, and the use of ion exchange resins will also lead to increased costs; (2) using water to replace and wash repeatedly to remove electrolytes, this method is cumbersome to operate, the preparation cycle is long, and a large amount of ion-containing wastewater will be generated in the preparation process , not conducive to industrial production

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0046] The following steps are used to quickly prepare airgel at low cost:

[0047] (1) Preparation of water-based alkane silica sol, mix butyl sodium silicate and water uniformly in proportion, add phosphoric acid during stirring, adjust the pH value of the mixture system to 6, and obtain water-based alkane silica sol;

[0048] (2) Preparation of alkaline organic solvent, add diphenylamine to n-butyl acetate, mix evenly, and the pH value is 11; wherein the volume ratio of butyl sodium silicate, water, and n-butyl acetate is 1:5:8

[0049] (3) Preparation of non-stable emulsion, add the mixed solution of step (2) to the water-based alkane silica sol of step (1), stir at high speed, add appropriate amount of dodecyl trimethyl chloride in the process of stirring Ammonium, continue to stir for 0.6h; the mass ratio of dodecyltrimethylammonium chloride to butyl sodium silicate is 1:60;

[0050] (4) Preparation of alkane gel, standing the unstable emulsion in step (3), layering, ge...

Embodiment 2

[0053] The following steps are used to quickly prepare airgel at low cost:

[0054] (1) Preparation of water-based alkane silica sol, mix ethyl potassium silicate and water uniformly in proportion, add nitric acid during the stirring process, adjust the pH value of the mixture system to 5, and obtain water-based alkane silica sol;

[0055] (2) Preparation of alkaline organic solvent: Add n-butylamine to toluene, mix well, and the pH value is 9; wherein the volume ratio of potassium ethyl silicate, water, and toluene is 1:7:10;

[0056] (3) Preparation of non-stable emulsion, add the mixed solution of step (2) to the water-based alkane silica sol of step (1), stir at high speed, add an appropriate amount of tetrabutylammonium chloride in the process of stirring, continue stirring 1h; the mass ratio of tetrabutylammonium chloride to potassium ethyl silicate is 1:30;

[0057] (4) Preparation of alkane gel, the unstable emulsion in step (3) was left to stand, layered, gelled, and...

Embodiment 3

[0060] The following steps are used to quickly prepare airgel at low cost:

[0061] (1) Preparation of water-based alkane silica sol, mixing lithium propyl silicate and water uniformly in proportion, adding hydrochloric acid during the stirring process, adjusting the pH value of the mixture system to 6, and obtaining water-based alkane silica sol;

[0062] (2) Preparation of alkaline organic solvent, add aniline to n-pentene, mix well, and the pH value is 10; wherein the volume ratio of propyl lithium silicate, water, and n-pentene is 1:5:8;

[0063] (3) Preparation of non-stable emulsion, add the mixed solution of step (2) to the water-based alkane silica sol of step (1), stir at a high speed, add an appropriate amount of benzyltriethylammonium chloride in the process of stirring, Continue stirring for 0.5h; the mass ratio of benzyltriethylammonium chloride to propyllithium silicate is 1:1;

[0064] (4) Preparation of alkane gel, standing the unstable emulsion in step (3), l...

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Abstract

The invention discloses a silica aerogel and a normal pressure drying preparation method and application thereof. The method comprises the following steps: 1) mixing a silicon source, water and an acid catalyst for a reaction, so as to obtain a sol; 2) dissolving an organic amine in a water-insoluble low-surface-tension solvent to obtain an alkaline organic solution; 3) mixing the sol with the alkaline organic solution under stirring, adding a phase transfer catalyst simultaneously during the mixing under stirring, so as to obtain an unstable emulsion; 4) allowing the unstable emulsion to stand for gelation and aging, so as to obtain a wet gel; and 5) performing atmospheric drying on the wet gel, so as to obtain a silica aerogel having a light weight, a large specific surface area and a low thermal conductivity. The method has the advantages of short process flow, high production efficiency and low cost, and the obtained silica aerogel has excellent comprehensive performance and can bewidely used as a thermal-insulating material, a sound absorbing material, an adsorbing material or an explosion-proof material.

Description

technical field [0001] The invention relates to a silica airgel and its preparation method and application, in particular to a method for quickly preparing silica airgel by normal pressure drying, and silica airgel in thermal insulation materials, sound-absorbing materials, etc. Applications such as materials, adsorption materials or explosion-proof materials belong to the technical field of preparation of nanometer mesoporous materials. Background technique [0002] Airgel is a light inorganic solid material with a three-dimensional network skeleton structure and nano-scale pores. It has extremely high porosity, specific surface area, extremely low density and solid content, chemical inertness and non-combustibility, and exhibits excellent It has the characteristics of heat insulation, fire prevention, sound insulation, shock absorption and energy absorption, and transparency. The thermal conductivity can be as low as 0.011W / m·K, which is the best heat insulation performanc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/158C01B33/155
CPCC01B33/155C01B33/1585C01P2006/10C01P2006/12C01P2006/32
Inventor 卢斌卢孟磊张丁日卢梦言左小荣卢珊卢军
Owner CENT SOUTH UNIV
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