Non-fluid colloidal network or polymer network that is expanded throughout its whole volume by a fluid.
  1. A gel has a finite, usually rather small, @[email protected]
  2. A gel can contain:
    1. a covalent @[email protected], e.g., a @[email protected] formed by @[email protected] polymer chains or by non-linear @[email protected];
    2. a @[email protected] formed through the physical aggregation of polymer chains, caused by hydrogen bonds, @[email protected], @[email protected] formation, complexation, etc, that results in regions of local order acting as the @[email protected] junction points. The resulting swollen @[email protected] may be termed a @[email protected] if the regions of local order are thermally reversible;
    3. a @[email protected] formed through glassy junction points, e.g., one based on @[email protected] copolymers. If the junction points are thermally reversible glassy domains, the resulting swollen @[email protected] may also be termed a @[email protected];
    4. lamellar structures including mesophases, e.g., @[email protected] gels, @[email protected] and clays;
    5. particulate disordered structures, e.g., a flocculent precipitate usually consisting of particles with large geometrical @[email protected], such as in V2O5 gels and globular or fibrillar protein gels.
  3. Corrected from previous definition where the definition is via the property identified in Note 1 (above) rather than of the structural characteristics that describe a gel.
PAC, 2007, 79, 1801. 'Definitions of terms relating to the structure and processing of sols, gels, networks, and inorganic-organic hybrid materials (IUPAC Recommendations 2007)' on page 1806 (