Silica gel
[CAS# 112926-00-8]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Oxides and peroxides >> Non-metal oxides and peroxides
• Name: Silica gel
• Synonyms: dioxosilane
• Molecular Formula: SiO₂
• Molecular Weight: 60.08
• CAS Registry Number: 112926-00-8
• EC Number: 601-214-2
• SMILES: O=[Si]=O

Properties

• Density: 2.6
• Melting point: 1610 ºC

Safety Data

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	2	H330
Specific target organ toxicity - repeated exposure	STOT RE	1	H372
Carcinogenicity	Carc.	1B	H350
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Reproductive toxicity	Repr.	2	H361fd
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin irritation	Skin Irrit.	2	H315
Germ cell mutagenicity	Muta.	1B	H340
Eye irritation	Eye Irrit.	2	H319
Flammable liquids	Flam. Liq.	2	H225
Aspiration hazard	Asp. Tox.	1	H304

Discovory and Applicatios

Silica gel, with the chemical formula SiO₂·nH₂O, is a porous and granular form of silicon dioxide commonly used as a desiccant and adsorbent. Its discovery and development have had a significant impact on a wide range of applications, from industrial processes to consumer products.

The origins of silica gel can be traced back to the early 20th century. The substance was first synthesized by French chemist Pierre Sylois in 1919. Sylois’s work involved the preparation of silica gel through the acidification of sodium silicate solutions. This process results in a gel-like substance composed of silicon dioxide, which can be subsequently dried to form the granular material known as silica gel. Over time, researchers developed methods to enhance the porosity and adsorption properties of silica gel, leading to its widespread use in various fields.

One of the primary applications of silica gel is as a desiccant. Its high surface area and porous structure make it highly effective at adsorbing moisture, which is essential for preserving the quality of products sensitive to humidity. Silica gel is commonly used in packaging to prevent the deterioration of pharmaceuticals, electronics, and food products. Small packets of silica gel are often found in boxes of new electronics, medicine bottles, and food containers, where they help maintain the integrity and extend the shelf life of the contents.

In addition to its use as a desiccant, silica gel is utilized in chromatography as a stationary phase for separating and analyzing compounds. In this application, silica gel is packed into columns and used to separate mixtures based on differences in their adsorption to the silica surface. This method, known as column chromatography, is widely used in both research and industry for purifying chemicals and analyzing complex mixtures.

Silica gel also finds application in catalysis. It is used as a support material for various catalysts, where its high surface area and stability enhance the performance of catalytic reactions. For example, silica gel-supported catalysts are employed in petrochemical refining and organic synthesis, where they facilitate chemical transformations and improve reaction efficiency.

The properties of silica gel, including its ability to adsorb and desorb moisture, have led to its use in a variety of other applications. For instance, it is used in the production of gas masks and air filters, where it helps remove impurities and moisture from air and gases. In addition, silica gel is used in the manufacturing of paints and coatings to control viscosity and improve performance.

Despite its many advantages, the environmental impact of silica gel production and disposal must be considered. The production process involves the extraction of silica from sand, which can have environmental consequences. Additionally, used silica gel, which is often discarded after it has reached its moisture capacity, can contribute to waste. Efforts are being made to recycle and repurpose silica gel to mitigate its environmental footprint and promote sustainability.

Ongoing research into silica gel continues to explore new uses and improve its properties. Advances in nanotechnology are leading to the development of nanoporous silica materials with unique characteristics, which could revolutionize applications in areas such as drug delivery, environmental remediation, and energy storage.

In summary, silica gel is a versatile material with a wide range of applications due to its unique adsorption properties and stability. Its discovery and development have made significant contributions to various industries, and continued research promises to uncover new and innovative uses for this important substance.

References

2025. Bioactive mesoporous silica materials-assisted cancer immunotherapy. Biomaterials.
DOI: 10.1016/j.biomaterials.2024.122919

2025. Magnetic mesoporous silica nanoparticles loaded with peptides for the targeted repair of cavernous nerve injury underlying erectile dysfunction. Biomaterials.
DOI: 10.1016/j.biomaterials.2024.122811

2025. Amine-functionalized organically modified silica for the effective adsorption of Chlorpyrifos and Triazophos Residues from Orange juice. Food Chemistry.
DOI: 10.1016/j.foodchem.2024.141967