Normal-pressure preparation method of high specific surface area intensive-hydrophobicity graphene oxide/silica composite aerogel

A high specific surface area, composite aerogel technology, applied in the direction of chemical instruments and methods, carbon compounds, silicon compounds, etc., can solve the problems of restricting the application of freeze-drying method, affecting the polycondensation process of precursors, and high airgel density. Achieve the effects of improving uneven pore size, shortening gel time, and high specific surface area

Inactive Publication Date: 2019-11-08
SOUTH CHINA UNIV OF TECH
View PDF8 Cites 19 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Although silica airgel has many excellent properties, it has the disadvantages of poor mechanical properties and easy moisture absorption.
The freeze-drying equipment used for drying is expensive, requires a vacuum environment and a very low drying temperature (generally lower than minus 40°C), consumes more energy, and freeze-drying has particularly high requiremen

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Normal-pressure preparation method of high specific surface area intensive-hydrophobicity graphene oxide/silica composite aerogel
  • Normal-pressure preparation method of high specific surface area intensive-hydrophobicity graphene oxide/silica composite aerogel
  • Normal-pressure preparation method of high specific surface area intensive-hydrophobicity graphene oxide/silica composite aerogel

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0052] Example 1

[0053] Ethyl orthosilicate, ethanol, and water were mixed in a molar ratio of 1:7:2, and after stirring at room temperature for 20 minutes, diluted hydrochloric acid was added dropwise to the mixed solution to pH=2, and the mixture was reacted for 8 hours at room temperature. DMF was added dropwise to the mixed solution, where the mass ratio of DMF to ethyl orthosilicate was 0.15:1. After stirring for 30 minutes, the ethanol solution of aminopropyltriethoxysilane was added dropwise to pH=6. Drop 0.018g of graphene oxide hydrosol with a mass fraction of 5%, sonicate for 30 minutes at a temperature of 20°C at a power of 50W, and continue to drop an ethanol solution of aminopropyltriethoxysilane into the mixed solution to pH =7.2, placed in an ultrasonic cleaner for 8 minutes to form a gel.

[0054] The formed alcogel was aged for 12 hours at room temperature, and then aged with a 20% water / ethanol mixture and a 20% ethyl orthosilicate / ethanol mixture for 24 hours,...

Example Embodiment

[0056] Example 2

[0057] Ethyl orthosilicate, ethanol, and water were mixed in a molar ratio of 1:14:2, and after stirring at room temperature for 25 minutes, dilute hydrochloric acid was added dropwise to the mixed solution to pH=2.5, and the mixture was reacted for 16 hours at room temperature. After adding DMF dropwise to the mixed solution and stirring for 30 minutes, the mass ratio of DMF to ethyl orthosilicate was 0.2:1, and the ethanol solution of aminopropyltriethoxysilane was added dropwise to pH=6. Drop 0.18g of graphene oxide hydrosol with a mass fraction of 15%, sonicate it at 25°C for 30 minutes at a power of 60W, and continue to drop the ethanol solution of aminopropyltriethoxysilane into the mixed solution to pH= 7.5. After 12 minutes in an ultrasonic cleaner, a gel is formed.

[0058] The formed alcogel was aged for 18 hours at room temperature, and then aged with a 15% water / ethanol mixture and a 15% ethyl orthosilicate / ethanol mixture for 36 hours, respectively,...

Example Embodiment

[0062] Example 3

[0063] Ethyl orthosilicate, ethanol, and water were mixed in a molar ratio of 1:14:3, and after stirring at room temperature for 30 minutes, dilute hydrochloric acid was added dropwise to the mixed solution to pH=3, and reacted at room temperature for 24 hours. After adding DMF dropwise to the mixed solution and stirring for 30 minutes, the mass ratio of DMF to ethyl orthosilicate is 0.25:1, and the ethanol solution of aminopropyltriethoxysilane is added dropwise to pH=6. Add 0.27g of graphene oxide hydrosol with a mass fraction of 20% dropwise, sonicate it at 30°C for 30 minutes under 80W power, and continue to drop the ethanol solution of aminopropyltriethoxysilane into the mixture to pH=8 , Placed in an ultrasonic cleaner for 18 minutes to form a gel.

[0064] The formed alcogel was aged for 24 hours at room temperature, and then aged with a 25% water / ethanol mixture and a 30% ethyl orthosilicate / ethanol mixture for 18 hours, respectively, with a volume fract...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Specific surface areaaaaaaaaaaa
Densityaaaaaaaaaa
Thermal conductivityaaaaaaaaaa
Login to view more

Abstract

The invention discloses a normal-pressure preparation method of a high specific surface area intensive-hydrophobicity graphene oxide/silica composite aerogel. The method comprises the following steps:by taking tetraethoxysilane as a precursor, adding a graphene oxide turbid liquid under an acidic condition, adding an ethanol liquid of aminopropyl triethoxy silane and graphene oxide hydrosol, continuously dropping the ethanol liquid of aminopropyl triethoxy silane, forming a graphene oxide/silica composite alcogel under an ultrasonic condition, and performing aging, maturing, solvent replacement, surface modification, and normal-pressure drying, so as to obtain the composite aerogel. By adopting the method, a silane coupling agent, namely the aminopropyl triethoxy silane, is adopted to replace a conventional alkali catalyst, and the aminopropyl triethoxy silane is used as a silicon source and is easy in chemical bond combination with an acidic group carboxyl in the graphene oxide because of an alkali group amino in the aminopropyl triethoxy silane, so that the combination force can be improved, in addition, the formation time of the gel is greatly shortened, and the graphene oxide/silica composite aerogel which is high in specific surface area, intensive in hydrophobicity and low in heat conduction coefficient can be prepared.

Description

technical field [0001] The invention relates to a silica composite aerogel, in particular to a method for preparing a graphene oxide / silicon dioxide composite aerogel at normal pressure with a high specific surface area and strong hydrophobicity, and belongs to the field of nanomaterial preparation. Background technique [0002] Silica airgel is a lightweight nanoporous material with high specific surface area, high porosity, low density, and low thermal conductivity. Silica airgel can be widely used in many fields. For example, in the field of building materials, silica aerogels can be used as thermal insulation materials; in the field of catalysts, silica aerogels can be used as carrier materials; they can also be used in the fields of adsorption and aerospace. [0003] Graphene is currently known as the thinnest material that can be artificially prepared, with a single atomic layer of only 0.33nm in thickness. between adjacent carbon atoms with sp 2 The hybrid arrangeme...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C01B33/158C01B33/159C01B33/155C01B32/198
CPCC01B32/198C01B33/155C01B33/1585C01B33/159C01P2004/80C01P2006/10C01P2006/12C01P2006/32
Inventor 袁文辉张孟蝶李莉肖强强
Owner SOUTH CHINA UNIV OF TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap