Normal-pressure rapid preparation method for hydrophobic silica aerogel powder

A hydrophobic silica and aerogel technology, applied in the polymer field, can solve problems such as unfavorable large-scale production and complex preparation process, and achieve the effects of uniform size and energy saving

Active Publication Date: 2016-11-09
ECONANO TECH LTD BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Chinese patent CN 104003406A adopts water glass or silicic acid as silicon source, together with oil phase, surfactant, co-surfactant, is formulated into microemulsion, and then neutralizes microemulsion until pH is 6-10 to form wet gel particles, wet coagulation The gel is aged, washed, and solvent-exchanged in sequence, and finally modified with a silane modifier and dried at normal temperature and pressure to obtain an airgel powder. Although airgel particles with a relatively uniform particle size can be obtained, the preparation The process is relatively complicated, which is not conducive to large-scale production

Method used

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  • Normal-pressure rapid preparation method for hydrophobic silica aerogel powder

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Experimental program
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Effect test

Embodiment 1

[0021] Mix and stir deionized water and water glass (3.55 mold, mass fraction 32.16%) at a volume ratio of 1:2; take 15ml of diluted water glass and add it to 3ml of 5M hydrochloric acid, and stir when adding to make it evenly mixed. The pH of the solution was controlled to be 2 to obtain solution A. Take 50ml of n-hexane, add 0.2ml of Span 80 into it, stir at 400r / min for 1min, and obtain solution B. Add solution A to solution B, mix well, then add 1ml of 5M ammonia water to it, adjust the pH of the solution to 5.5, keep stirring at high speed during this step, add ammonia water and stir for 2 minutes, the stirring speed is 300r / min, Form uniform gel small particles. The gel particles were aged in a water bath at 45 °C for 1 h. Pour out and recover the remaining n-hexane and Span 80 in the gel, then add 25ml of trimethylchlorosilane, 12ml of ethanol and 50ml of n-hexane to the gel particles for exchange and modification in a water bath at 45°C. After 6 hours, add 10ml of w...

Embodiment 2

[0023] Mix and stir deionized water and water glass (3.55 mold, mass fraction 32.16%) at a volume ratio of 1:4; take 15ml of diluted water glass and add it to 3ml of 5M hydrochloric acid, and stir when adding to make it evenly mixed. The pH of the solution was controlled to be 2 to obtain solution A. Take 50ml of n-hexane, add 0.2ml of Span 80 into it, stir at 400r / min for 1min, and obtain solution B. Add solution A to solution B, mix well, then add 1ml of 5M ammonia water to it, adjust the pH of the solution to 6, keep stirring at high speed during this step, add the alkaline catalyst and stir for 2 minutes to form a uniform gel small particles. The gel was aged in a water bath at 45 °C for 1 h. Pour out and recover the remaining n-hexane and Span 80 in the gel, then add 25ml of trimethylchlorosilane, 12ml of ethanol and 50ml of n-hexane to the gel particles for exchange and modification in a water bath at 45°C. After 6 hours, add 10ml of water into the container and stir ...

Embodiment 3

[0025] Mix and stir deionized water and water glass (3.55 mold, mass fraction 32.16%) at a volume ratio of 1:3; take 30ml of diluted water glass and add it to 6ml of 5M hydrochloric acid, and stir when adding to make it evenly mixed. The pH of the solution was controlled to be 2 to obtain solution A. Take 150ml of n-hexane, add 0.5ml of Span 80 into it, stir at 600r / min for 1min, and obtain solution B. Add solution A to solution B, mix well, then add 2ml of 5M ammonia water to it, adjust the pH of the solution to 6, keep stirring at high speed during this step, add the alkaline catalyst and stir for 2 minutes to form a uniform gel small particles. The gel was aged in a water bath at 45 °C for 1 h. Pour out and recycle the remaining n-hexane and Span 80 in the gel for next use. Afterwards, 55ml of hexamethyldisilazane, 24ml of ethanol and 100ml of n-hexane were added to the gel particles, and exchange and modification were carried out in a water bath at 45°C. After 6 hours,...

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Abstract

The invention discloses a normal-pressure rapid preparation method for hydrophobic silica aerogel powder. The method comprises the following steps: preparing gel particles at first; then carrying out exchanging and modification with a non-polar solvent, alcohols and a silane coupling agent as modifier solutions; and drying modified wet silica aerogel so as to obtain the hydrophobic silica aerogel powder. According to the invention, industrial soluble glass is used a silicon source for formation of the gel particles with a uniform size in a dispersion phase under the action of an emulsifier and a catalyst, then the gel particles are modified by using a one-step solvent exchange and surface modification method, and finally, drying at normal pressure is carried out so as to directly obtain the silica aerogel powder. The normal-pressure rapid preparation method for the hydrophobic silica aerogel powder substantially reduces time for sol exchanging and surface modification; the prepared silica aerogel powder has a uniform size; and a great amount of energy is saved in normal pressure drying compared with supercritical drying.

Description

technical field [0001] The invention belongs to the technical field of macromolecules, in particular to a rapid preparation method of hydrophobic silicon dioxide airgel powder under normal pressure. Background technique [0002] Currently, SiO 2 Airgel powder is generally prepared by preparing airgel blocks and then grinding them into powder, or by spraying or emulsion methods. Preparation of SiO by Atmospheric Pressure Drying 2 The production cycle of airgel blocks is long, and it is prone to incomplete modification, which makes the prepared SiO 2 The quality of airgel powder is not good; SiO prepared by spray method 2 Airgel powders are prone to cohesion and agglomeration of droplets during the spraying process, resulting in powders with a particle size of more than 1mm; SiO prepared by emulsion method 2 For airgel, due to the non-uniform size of the emulsion droplets, the prepared airgel powder has a wide particle size distribution range. [0003] Chinese patent CN 1...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/16
CPCC01B33/16C01P2004/03C01P2006/11
Inventor 何松刘忠程旭东李治石小靖
Owner ECONANO TECH LTD BEIJING
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