Silica aerogels based on sodium silicate
Silica aerogels are known as one of the most advanced thermal and sound insulation materials and are produced from sodium silicate as a raw material. Due to their nanoporous structure and very low weight, these materials have unique capabilities in various industries, including construction, aerospace, and medicine. In this article, we examine the details of silica aerogels based on sodium silicate, their production methods, characteristics and applications.
Structure and properties of silica aerogels
Nanoporous structure
Silica aerogels have a nanoporous structure, which makes them light weight and one of the lightest solid materials.This structure consists of a network of nano particles that are connected by silicon bonds and the empty spaces between them are filled with air or gas.
Physical and chemical properties
Light weight: Silica aerogels with a density of about 0.03 to 0.1 g / cm3 are one of the lightest solid materials.
Thermal insulation: These materials have very low thermal conductivity and are known as very effective thermal insulation.
Sound insulation: The nanoporous structure of aerogels has made them very efficient sound insulation.
Chemically inert: Silica aerogels are resistant to many chemicals due to their high chemical stability.
Production methods of silica aerogels based on sodium silicate
Primary synthesis
The production of silica aerogels begins with the use of sodium silicate as the main raw material.The synthesis process includes the following steps:
Hydrolysis and condensation: First, sodium silicate solution reacts with a suitable acid (such as hydrochloric acid) and silica gel is formed. This process involves hydrolysis of sodium silicate and then condensation of silica particles.
Gelation: Silica gel turns into a strong and stable gel with the passage of time and adjustment of conditions such as pH and temperature.
Supercritical drying
The next important step is to dry the silica gel to convert it into an aerogel. This step is done in two main ways:
Supercritical drying: In this method, the gel is dried in an environment under pressure and high temperature to turn into an aerogel without changing the nanoporous structure.
Solvent drying: In this method, the solvent in the gel is replaced with another solvent and then slowly evaporates.Applications of silica aerogels based on sodium silicate
Insulation
Silica aerogels are known as thermal insulation in various industries due to their very low thermal conductivity. These materials can be used in buildings, oil and gas industries, and electronic equipment to reduce heat transfer and increase energy efficiency.
sound insulation
Due to the nanoporous structure, silica aerogels are known as very effective sound insulators. These materials can be used in walls and ceilings of buildings, recording studios and industrial environments to reduce noise and improve sound quality.
Aerospace
In the aerospace industry, silica aerogels are used as thermal and acoustic insulators in the construction of airplanes and spacecraft.The low weight and high performance of these materials have made them an ideal choice in this industry.
medical
Silica aerogels are also used in medical fields. These materials can be used in the manufacture of wound dressings and release control drugs and are suitable for medical uses due to their chemical inertness and high stability.
Advantages and disadvantages of silica aerogels based on sodium silicate
Advantages
Very light weight: Due to their nanoporous structure, silica aerogels are one of the lightest solid materials available.
Excellent thermal and acoustic insulation: These materials have very low thermal and acoustic conductivity, which makes them very effective insulators.
High chemical resistance: Silica aerogels are resistant to many chemicals.High durability and stability: These materials have high stability and durability, which makes them suitable for long-term applications.
Disadvantages
High production cost: The production process of silica aerogels is complex and expensive.
Sensitivity to moisture: Silica aerogels are sensitive to moisture and must be properly protected so that their performance is not affected.
Summary about silica aerogels based on sodium silicate
Silica aerogels based on sodium silicate are known as one of the most advanced insulating materials in various industries. These materials have wide applications with features such as light weight, excellent thermal and acoustic insulation, and high chemical resistance. Despite the high costs of production, the numerous advantages of these materials have made them continue to be considered in many fields.Finally, silica aerogels with their unique properties can play an important role in the advancement of insulation technologies and improving the performance of various industries.
common questions
How are silica aerogels produced?
Silica aerogels are produced by hydrolysis and condensation of sodium silicate followed by supercritical drying or solvent drying.
Are silica aerogels moisture resistant?
Silica aerogels are sensitive to moisture and must be properly protected so that their performance is not affected.
What are the main uses of silica aerogels?
The main applications of silica aerogels include heat and sound insulation in buildings, aerospace and medical industries.Are silica aerogels environmentally friendly?
Yes, silica aerogels are environmentally friendly materials due to their chemical inertness and high stability.
How to reduce the production cost of silica aerogels?
Optimizing production processes and using cheaper raw materials can help reduce the cost of producing silica aerogels