Silica Aerogel Manufacturing via Two-Step Precursor Segmentation
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Solution Overview
Problem
The existing methods for producing silica aerogels are complex, costly, and time-consuming, and they struggle to maintain the mechanical properties and controllability of specific surface area and pore characteristics, as well as hydrophobicity, which are essential for industrial applications.
Innovation Solution
A two-step process involving the formation of silica colloid particles using a low-concentration silica precursor followed by a growth step with a higher concentration precursor, allowing for improved mechanical stability and controllable physical properties, including surface modification and solvent exchange in a single step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conventional sol-gel method is used to produce silica aerogel, then the aerogel can be produced with super-insulation properties, but the process becomes very complicated, costly, and time-consuming, deteriorating productivity and economical efficiency
Solution Approach 1:
The conventional sol-gel process is segmented into two distinct steps: a nucleation step using low-concentration silica precursor (0.01-2 wt%) to form silica colloid particles, and a growth step using high-concentration silica precursor (1-11 wt%) to grow the wet gel. This segmentation allows optimization of each step independently, improving both product quality and production efficiency while maintaining the desired insulation properties.
2Reliability
If the conventional sol-gel method with multiple steps is used, then the aerogel can be produced, but the process requires much cost and time, thus deteriorating the economical efficiency
Solution Approach 1:
The invention merges multiple operations into the growth step: adding high-concentration silica precursor, performing surface modification with hydrophobic agents, and conducting solvent exchange all in a single step. This consolidation eliminates separate processing steps, reducing both time and cost while maintaining aerogel production quality and hydrophobicity.
3Reliability
If the silica aerogel is produced by conventional methods, then it can be manufactured, but the mechanical properties are not improved and the specific surface area and pore characteristics are not optimized
Solution Approach 1:
The nucleation step using low-concentration silica precursor is performed in advance to form uniform silica colloid particles that serve as seeds. This preliminary action creates a controlled foundation for subsequent gel growth, ensuring uniform pore distribution, optimized specific surface area, and improved mechanical properties in the final aerogel product.
Solution Approach 2:
The invention changes the concentration parameter of silica precursor between steps: low concentration (0.01-2 wt%) in the nucleation step to form colloid particles, and high concentration (1-11 wt%) in the growth step to develop the gel structure. This parameter change enables precise control over the aerogel's pore characteristics and specific surface area while improving mechanical properties.
4Adaptability or versatility
If the silica aerogel absorbs moisture, then it can be used in applications, but the characteristics and physical properties of the gel structure are deteriorated
Solution Approach 1:
Hydrophobic surface-modifying agents are introduced as intermediaries that coat the silica surface. These agents form a protective layer that prevents moisture from interacting with and deteriorating the gel structure, allowing the aerogel to maintain its physical properties while remaining usable in various applications including humid environments.
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
This approach enhances the mechanical stability and specific surface area of silica aerogels, reduces production time, and improves economic efficiency by allowing for easier control of physical properties and maintaining hydrophobicity, thus overcoming the limitations of traditional methods.
Implementation Method 1
adding an acid catalyst and a first water glass solution to a reactor to prepare a water glass dispersion solution for forming silica colloid particles
Implementation Method 2
adding an acid catalyst and a first water glass solution to a reactor to prepare a water glass dispersion solution for forming silica colloid particles
Implementation Method 3
adding a surface modifier solution to the water glass dispersion solution for forming silica colloid particles, to form silica colloid particles
Implementation Method 4
adding the water glass dispersion solution for forming a wet gel to the reactor including the silica colloid particles to form a silica wet gel
Implementation Method 5
drying the silica wet gel
Data Source
AI summary
The present invention relates to a method for producing a silica aerogel and a silica aerogel produced thereby. The present invention provides a two-step process of a nucleation step of forming silica colloid particles by using a low-concentration silica precursor and a growth step of further adding a relatively high-concentration silica precursor to form a silica wet gel by using the silica colloid particles as a seed. Thus, the present invention provides a method for producing a silica aerogel of which mechanical stability is improved to enhance pore characteristics, and physical properties are readily controllable, and also provides a silica aerogel produced thereby.