Preparation method and applications of super-hydrophobic SiO2 aerogel powder

A super-hydrophobic, aerogel technology, applied in chemical instruments and methods, inorganic chemistry, fibrous fillers, etc. Problems such as poor quality of aerogel powder, to achieve the effect of adjustable particle size distribution, short preparation cycle, and reduced production energy consumption

Inactive Publication Date: 2014-08-27
WUHAN UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Airgel blocks prepared by normal pressure drying have a long production cycle and are prone to incomplete modification, resulting in poor quality of the prepared airgel powder; the airgel powder prepared by the spray method is easy During the process, the droplets are cohesive and agglomerated, resulting in a powder with a particle size of more than 1mm; the airgel prepared by the emulsion method has a wide particle size distribution range due to the uneven size of the emulsion droplets.

Method used

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  • Preparation method and applications of super-hydrophobic SiO2 aerogel powder
  • Preparation method and applications of super-hydrophobic SiO2 aerogel powder
  • Preparation method and applications of super-hydrophobic SiO2 aerogel powder

Examples

Experimental program
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Effect test

Embodiment 1

[0034] With 20% mass fraction of silicic acid sol as raw material, add 10ml kerosene and 2ml silicic acid sol in the container, and add 0.8g cetyltrimethylammonium bromide (CTAB) and 2.8g co-surfactant n-butyl alcohol. Use a 250rpm magnetic stirrer to stir until the liquid in the container changes from a milky white emulsion to a clear and transparent microemulsion. While stirring, add ammonia solution of pH ~ 12 dropwise, until the microemulsion is viscous, the reaction is completed, and fine wet gel particles are formed in the container. Add deionized water to the container, soak for 6h aging, wash with absolute ethanol, and filter with suction to remove kerosene and excess CTAB. The wet gel after suction filtration was replaced with alcohol and n-hexane as solvents for 2 hours and dispersed under ultrasonic waves at a frequency of 25 Hz for 1 hour. Use a solution of n-hexane and trimethylchlorosilane (TMCS) at a ratio of 2:1 for hydrophobic modification, wash the unreacte...

Embodiment 2

[0036]Dilute the sodium water glass with a modulus of 3.0 according to the water: water glass volume ratio (3:1), stir and filter evenly to obtain a water glass solution, add 10ml kerosene and 4ml water glass solution to the container, and add 4g dodecylsulfuric acid Sodium (SDS) and 3.5 g co-surfactant 2,4-hexanediol. Under stirring at 200 rpm, the liquid in the container changed from a milky white emulsion to a clear and transparent microemulsion. Add 2mol / L sulfuric acid solution dropwise while stirring, until the microemulsion is viscous, the reaction is completed, and wet gel particles are formed in the container. Add deionized water to the container, soak for 8 hours, age, wash alternately with absolute ethanol and deionized water, and filter 8 times to remove kerosene and excess SDS and Na + . The wet gel after suction filtration was replaced with alcohol and octane as solvents for 12 hours respectively. Use octane: TMCS (1:2) solution for solvent replacement and hyd...

Embodiment 3

[0038] Dilute sodium water glass with a modulus of 3.2 according to water: water glass volume ratio (4:1) and stir evenly, pass the diluted water glass through 732 sodium type strong acid styrene ion exchange resin to remove Na + , to obtain silicic acid sol. Take 20ml of heptane and 4ml of silicic acid sol, and add 1.6g of cetyltrimethylammonium bromide (CTAB) and 3.0g of co-surfactant n-butanol. Use a magnetic stirrer to stir until the liquid in the container changes from a milky white emulsion to a clear and transparent microemulsion. Add 2mol / L sodium hydroxide solution dropwise while stirring, until the microemulsion is viscous, the reaction is completed, and fine wet gel particles are formed in the container. After aging by immersion in deionized water for 8 h, it was washed with deionized water to remove CTAB. The wet gel after suction filtration was replaced with alcohol and heptane as solvents for 4 hours respectively and dispersed for 30 minutes under ultrasonic wa...

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Abstract

The invention relates to a preparation method and applications of super-hydrophobic SiO2 aerogel powder. The method is implemented through the following steps: preparing a silicon source solution, an oil phase, a surfactant and a surfactant aid into a microemulsion; then, neutralizing the microemulsion until the pH value is 6-10 so as to form wet microgel particles; sequentially carrying out ageing, washing and solvent exchange on the wet microgel particles; finally, modifying the obtained product by using a silane modifier, and drying gel at normal pressure and temperature so as to obtain aerogel powder. The method is capable of preparing aerogel powder by using a microemulsion, the particle size of aerogel powder prepared by using the method is uniformly distributed, and prepared aerogel powder has the characteristics of controllable particle size distribution, short preparation period, and capability of being dried at normal pressure and temperature.

Description

technical field [0001] The invention belongs to the technical field of preparation of inorganic non-metallic materials, in particular to a superhydrophobic SiO 2 Preparation method and application of airgel powder. Background technique [0002] SiO 2 Airgel is a unique porous solid material that is highly cross-linked and aggregated by nano-scale particles. It has a continuous three-dimensional network structure. It is composed of more than 90% air and less than 10% solid. SiO 2 The structural characteristics of airgel make it have special properties in terms of mechanics, heat, acoustics, optics, electricity, etc., for example, it has an ultra-low apparent density (0.03g / cm 3 around), ultra-low thermal conductivity (below 0.03W / m·K), high specific surface area (600~1200m 2 / g), low refractive index, low acoustic resistance, strong adsorption performance, etc. SiO 2 As a new material, airgel will have broad application prospects in the fields of thermal insulation, med...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/14C01B33/159C01B33/158C09C1/28C09C3/12C09C3/08C09D1/00C04B41/50
Inventor 陈伟劳里林水中和
Owner WUHAN UNIV OF TECH
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