Method for preparing bulk-shaped flexible aerogel through normal-pressure drying

A technology of normal pressure drying and shape flexibility, which is applied in the field of airgel materials and atmospheric pressure drying to prepare large flexible airgel. It can solve the problems of pore size and pore structure breakage, and achieve high porosity, excellent support effect, The effect of good compound processability

Active Publication Date: 2017-02-22
正一集团有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Aiming at the defects such as uneven stress of the airgel support body prepared by normal pressure drying, which easily leads to pore size and pore structure breakage, the present invention provides a method for preparing large flexible airgel by normal pressure drying. Its outstanding feature is that The fiber crystal nuclei are dispersed in the wet gel, and the crystal nuclei grow to form uniformly dispersed nanofibers through continuous graded heating and reaction control, and further grow and connect to form a uniform supporting stress on the gel network

Method used

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  • Method for preparing bulk-shaped flexible aerogel through normal-pressure drying

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Experimental program
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Effect test

Embodiment 1

[0029] (1) Evenly mix deionized water and industrial water glass together, stir evenly, add acetic acid solution, adjust the pH value to 5-8, and form a hydrogel after standing for 1 hour;

[0030] (2) Pour the hydrogel obtained in step (1) into a drainable block mold, pass through the ammonia solution containing 25% ammonia continuously for aging, then rinse with water to obtain the aged wet gel, and place it naturally through the drainable Drain the mold naturally;

[0031] (3) The aged wet gel obtained in step (2) is subjected to primary drying at a temperature of 60-80°C, and the drying time is controlled at 35 minutes. The reduction of the volume of the gel is equal to the volume of the liquid evaporation. At this time, the gel network will not collapse and has toughness, and then continuously pass through the calcium chloride solution with a saturated concentration of the fiber crystal nucleus liquid to make the fiber crystal nucleus enter the gel network;

[0032](4) P...

Embodiment 2

[0036] (1) Evenly mix deionized water and industrial water glass together, stir evenly, add sulfuric acid solution, adjust the pH value to 5-8, and form a hydrogel after standing for 1 hour;

[0037] (2) Pour the hydrogel obtained in step (1) into a drainable block mold, aging through ammonia solution continuously, and then rinse with water to obtain an aged wet gel;

[0038] (3) The aged wet gel obtained in step (2) is subjected to primary drying at a temperature of 60-80°C, and the drying time is controlled at 25 minutes. The reduction of the volume of the gel is equal to the volume of the liquid evaporated. At this time, the gel network will not collapse and has toughness, and then continuously pass through the calcium acetate fiber crystal nucleus liquid to make the fiber crystal nucleus enter the gel network;

[0039] (4) Pass the gel obtained in step (3) through sodium silicate aqueous solution and sodium hydroxide aqueous solution continuously, initiated by sodium hydro...

Embodiment 3

[0043] (1) Evenly mix deionized water and industrial water glass together, stir evenly, add citric acid solution, adjust the pH value to 5-8, and form a hydrogel after standing for 1 hour;

[0044] (2) Pour the hydrogel obtained in step (1) into a drainable block mold, aging through ammonia solution continuously, and then rinse with water to obtain an aged wet gel;

[0045] (3) The aged wet gel obtained in step (2) is subjected to primary drying at a temperature of 60-80°C, and the drying time is controlled at 30 minutes. After primary drying, enough liquid phase is filled in the gel pores, and the gel The reduction of the volume of the gel is equal to the volume of the liquid evaporated. At this time, the gel network will not collapse and has toughness, and then continuously pass through the calcium nitrate fiber crystal nucleus liquid to make the fiber crystal nucleus enter the gel network;

[0046] (4) Pass the gel obtained in step (3) through sodium silicate aqueous soluti...

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Abstract

The invention belongs to the field of heat insulation and particularly relates to an aerogel material. A method for preparing bulk-shaped flexible aerogel through normal-pressure drying is provided aiming at the defects that when aerogel is prepared through normal-pressure drying in the prior art, fibers and other supports are directly added, and stress is not uniform, so that hole diameters and hole structures are broken. According to the method, fiber crystal nuclei are dispersed in wet gel, the crystal nuclei grow through continuous graded heating and reaction control to form uniformly-dispersed nano-fibers, further growth connection is carried out, and uniform supporting stress is provided for a gel network. Meanwhile, the nano-fibers grow in nano network holes of the gel, and the supporting effect of the nano-fibers is more excellent. The bulk-shaped aerogel obtained through normal-pressure drying is integral and uniform in network structure, low in density, high in porosity and good in strength and toughness.

Description

technical field [0001] The invention belongs to the field of thermal insulation, and in particular relates to an airgel material, in particular to a method for preparing bulky flexible airgel by drying under normal pressure. Background technique [0002] Due to its nanoporous structure, low density, low dielectric constant, low thermal conductivity, high porosity, and high specific surface area, aerogels have unique properties in mechanics, acoustics, heat, and optics. Due to the high cost of airgel preparation, it has been used in high-end fields such as aerospace and military. However, with the continuous improvement of technology, its cost has been continuously reduced, so its application in civilian applications has great potential. Airgel is the material with the best thermal insulation performance so far, especially in the thermal insulation fields of petroleum, chemical industry and construction, the use of aerogel will become the mainstream. [0003] Airgel is a ch...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B28/24C04B38/00
CPCC04B28/24C04B2201/32C04B2201/50C04B14/38C04B38/0045
Inventor 陈庆曾军堂
Owner 正一集团有限公司
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