What is the difference between Colloidal silica/Silica Sol with Large Particle Size and ordinary silica sol?

Colloidal Silica is a colloidal solution formed by silica (SiO₂) particles evenly dispersed in water or organic solvents. Among them, Large Particle Size Silica Sol, as a special type of silica sol, is significantly different from ordinary silica sol in many aspects.

1. Particle size
Large particle size silica sol: Its most significant feature is that its particle size is relatively large, usually ranging from tens of nanometers to several microns. This larger particle size allows large particle size silica sol to be used in specific applications. Show unique advantages in application.
Ordinary silica sol: In comparison, the particle size of ordinary silica sol is usually smaller, generally ranging from a few nanometers to tens of nanometers. This small particle size characteristic gives ordinary silica sol excellent properties such as high dispersion and high specific surface area.

2. Film-forming and adhesive properties
Large particle size silica sol: Due to its larger particle size, large particle size silica sol can form a stronger film structure during drying or sintering. This membrane structure has high mechanical strength and also exhibits good weather resistance and corrosion resistance. In addition, large particle size silica sol also has good bonding properties and can enhance the adhesion of coatings or products.
Ordinary silica sol: Ordinary silica sol also has good adhesion and film-forming properties, but the strength and adhesion of its film structure may be slightly inferior to large particle size silica sol. This is mainly due to the relatively loose network structure formed during the film formation process due to its smaller particle size.

3. Application fields
Large particle size silica sol: Due to its unique particle size characteristics and excellent film-forming and adhesive properties, large particle size silica sol is widely used in fields that require high film thickness, hardness and wear resistance. In the semiconductor and optoelectronics industries, large particle size silica sol is often used as polishing fluid and abrasive; in ceramic and glass manufacturing processes, it can be used as a binder and flux.
Ordinary silica sol: Ordinary silica sol is widely used in many fields such as coatings, inks, papermaking, and textiles due to its high dispersion and high specific surface area. It can be used as an additive to improve the rheology and dispersion of coatings, and improve the adhesion and wear resistance of coatings; in the papermaking industry, it can be used as a reinforcing agent and surface sizing agent for paper.

4. Preparation process
Large particle size silica sol: The preparation of large particle size silica sol usually requires the adoption of specific process conditions and control methods. By adjusting parameters such as temperature, time, catalyst type and dosage of the silica powder hydrolysis reaction, precise control of the silica sol particle size can be achieved.
Ordinary silica sol: The preparation process of ordinary silica sol is relatively mature and diversified. Two major methods, including physical methods and chemical methods, can be used to prepare ordinary silica sol. Among them, chemical methods such as sodium silicate acidification method, silicate ester hydrolysis method, etc. are relatively common preparation methods.