A colloidal gel is formed by introducing an attractive potential between dispersed colloidal particles. Depending on the strength of the attractive potential, gels can be formed even at arbitrarily low volume fractions. This gel has a finite elastic modulus and can resist shears stresses. Once the material begins to yield, it flows freely similar to a liquid. This alone shows some of the interesting characteristics exhibited by these materials.
Colloidal gels are fractals at distances lower than their correlation length, but appear homogeneous at other length scales. Examining their structure reveals a network of interconnected colloidal strands.
- Dinsmore, A.D., Prasad, V., Wong, I.Y. & Weitz, D.A. "Microscopic Structure and Elasticity of Weakly Aggregated Colloidal Gels." Physical Review Letters, (2006), 96, 1885502-1 to 1885502-4.