G

Gel

Quick Reference
Also Known AsHydrogel, xerogel (dried gel), silica gel, physical gel, chemical gel

What is Gel?

A colloid in which a liquid is dispersed within a solid or semi-solid matrix, forming a jelly-like substance. Gels have properties between a solid and a liquid. Examples include gelatin, agar, silica gel, and hydrogels used in biomedical applications.

Properties & Characteristics

A gel is a colloidal system in which a liquid is entrapped in a three-dimensional solid or semi-solid polymer or inorganic network. The network prevents flow, giving gel-like rheological properties (elastic solid behaviour at low stress, viscous flow at high stress). Examples: gelatin (protein network in water), silica gel (SiO₂ network), agar, polyacrylamide gel (PAG used in electrophoresis), hydrogels (crosslinked polymer networks).

Uses & Applications

Gels are used in: food products (jellies, yoghurt, desserts), pharmaceuticals (topical gels, wound dressings, contact lenses), analytical chemistry (silica gel chromatography, polyacrylamide gel electrophoresis), cosmetics, and materials science (aerogels as ultra-lightweight insulators).

Safety Information

Acrylamide monomer (used to make polyacrylamide gels) is a potent neurotoxin and potential carcinogen. Always handle unpolymerised acrylamide in a fume hood with gloves. Silica gel dust is a respiratory irritant. Some food gels contain allergens (gelatin from animal sources).

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Gel
Synonyms Hydrogel, xerogel (dried gel), silica gel, physical gel, chemical gel

Frequently Asked Questions

A colloid in which a liquid is dispersed within a solid or semi-solid matrix, forming a jelly-like substance. Gels have properties between a solid and a liquid. Examples include gelatin, agar, silica gel, and hydrogels used in biomedical applications.

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