Alkoxy Silicate Aerogel Formation Without Solvent Exchange
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Solution Overview
Problem
Conventional methods for forming silica aerogels are laborious, costly, and require extensive solvent exchange steps, making them inefficient and expensive, while supercritical drying is necessary for achieving desired thermal conductivity.
Innovation Solution
A method involving the hydrolysis of alkoxy silicate in a hydrolytic solvent, followed by mixing with a basic solution, aging, and heating to form an alkoxy silicate-based aerogel material, which eliminates solvent exchange steps and achieves thermal conductivity of ≤18 mW/mK through ambient drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to form silica aerogel, then thermal conductivity can be achieved, but the process requires lengthy solvent exchange steps and copious amounts of organic solvents, increasing production costs and labor
Solution Approach 1:
The patent extracts and eliminates the lengthy solvent exchange steps from the conventional aerogel formation process. By using a modified sol-gel method with specific pH control and aging conditions, the process achieves thermal conductivity ≤18 mW/mK without requiring multiple solvent exchanges, thereby reducing production time and costs
Solution Approach 2:
The patent applies parameter changes by controlling the pH level during hydrolysis (pH 1-4) and using specific aging conditions (temperature, time) to optimize the aerogel structure. These parameter optimizations enable achieving desired thermal conductivity while eliminating the need for extensive solvent exchange procedures
2Reliability
If TEOS derived aerogels are produced, then thermal conductivity can be achieved, but the process is significantly costlier and requires lengthy solvent exchange steps
Solution Approach 1:
The patent employs waterglass and SiCl4 as cheaper alternatives to TEOS while achieving comparable thermal conductivity. The modified sol-gel process uses readily available materials and simplifies the manufacturing procedure, reducing production costs without sacrificing the desired thermal performance
Solution Approach 2:
By optimizing pH levels (pH 1-4) and aging conditions, the patent enables the use of cheaper precursors like waterglass and SiCl4 to produce aerogels with thermal conductivity ≤18 mW/mK, making the manufacturing process more cost-effective while maintaining product quality
3Manufacturing precision
If conventional methods are used, then aerogel can be formed, but extensive washing with alcohols is required to displace residual salt ions, increasing labor and time
Solution Approach 1:
The patent extracts and eliminates the extensive alcohol washing steps from the conventional process. By using a modified sol-gel method with controlled pH and aging, the method achieves sufficient purity to displace residual salt ions without requiring lengthy washing procedures, thereby reducing labor and time while maintaining manufacturing precision
4Reliability
If supercritical drying is used, then desired thermal conductivity can be obtained, but the process complexity and cost increase
Solution Approach 1:
The patent replaces the complex supercritical drying system with a simpler ambient pressure drying process. By optimizing the sol-gel formulation, pH control, and aging conditions, the method achieves thermal conductivity ≤18 mW/mK through conventional heating and drying techniques, eliminating the need for expensive and complex supercritical drying equipment
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method simplifies the process, reduces costs, and produces aerogels with superior thermal conductivity and specific surface area, comparable to or better than those produced by supercritical drying, without the need for multiple solvent exchanges.
Implementation Method 1
hydrolysing an alkoxy silicate in a hydrolytic solvent to form a silica sol
Implementation Method 2
heating the sol-gel at a temperature of 120-250° C. to form the alkoxy silicate-based aerogel material
Data Source
AI summary
There is provided a method of making an alkoxy silicate-based aerogel material, the method comprising: hydrolysing an alkoxy silicate in a hydrolytic solvent to form a silica sol for a pre-determined period of time and at a pH of 1-4; mixing the silica sol with a basic solution to form a sol-gel; a first ageing the sol-gel; adding a surface-modifying agent to the sol-gel; a second ageing the sol-gel; and heating the sol-gel at a temperature of 120-250° C. to form the alkoxy silicate-based aerogel material, wherein the alkoxy silicate-based aerogel material has a thermal conductivity of <18 mW/mK. There is also provided an alkoxy silicate-based aerogel material formed from the method.