gélek

Gélek, the plural form of the Hungarian word gél, refer to gels in general. In scientific terms, gels are semi-solid substances formed when a three-dimensional network of polymers entraps a large amount of liquid, typically water, giving a material that behaves as a solid but can deform like a liquid. They occupy a state between liquids and solids and are distinguished from simple emulsions or suspensions by their continuous, interconnected network.

Gelation can occur through chemical crosslinking, where covalent bonds join polymer chains, or through physical crosslinking, which relies on non-covalent interactions such as hydrogen bonds, ionic interactions, or crystallization. The properties of a gel depend on the network structure, crosslink density, and the amount and type of trapped liquid. Temperature, pH, and solvent quality strongly influence gel formation, stability, and response to stress.

Gels are diverse and widely used. Hydrogels contain mostly water and are common in biomedicine and tissue engineering due to biocompatibility. Organogels contain organic solvents and are used in cosmetics and delivery systems. Xerogels are dried gels with a porous solid network. In food science, gels such as gelatin, pectin, and starch gels provide texture; in pharmaceuticals and cosmetics, gel formulations enable controlled release and topical delivery.

Common laboratory and industrial gels include gelatin, agarose, alginate, and polyacrylamide gels, the latter frequently used in electrophoresis and chromatography. Gel properties are characterized by mechanical and transport metrics, including storage and loss moduli, gel point, and permeability. Gélek is thus a general term encompassing a range of materials with a soft, interconnected structure capable of retaining large amounts of liquid.