Rheology of Particulate Gels

Rheological measurements on concentrated, strongly flocculated gels are hampered by the following difficulties (Buscall et al. 1986, 1993 Rueb and Zukoski 1997)  

Extremely limited range of linear viscoelastic response 

The first three or four of these experimental difficulties arise because of the nonequilibrium structure of strongly flocculated gels. Particles bound strongly together in their 

These problems can be avoided in weakly flocculated gels, which attain thermodynamic equilibrium on experimental time scales. Since an understanding of weakly flocculated gels can form the basis for study of strongly flocculated gels, we shall consider the former first. 

The expression for the zero-shear viscosity for the adhesive hard-sphere model at modest particle volume fraction is (Woutersen and de Kruif 1991)------------------------ 

---

Stading, M., Langton, M. and Hermansson, A.-M. Microstructure and rheological behaviour of particulate 3-lactoglobulin gels. Food Hydrocolloids, 7, 195,1993. 

Rheology is a product attribute frequently exploited in personal care products to create visual appeal to prospective consumers. Liquid products in transparent packaging may highlight the gel strength of the continuous phase with obvious suspension of the particulate phases. In certain instances, aeration may be introduced to emphasize the gel-like consistency of the product. Premium brand products may include stable suspensions captured within the gel matrix of encapsulated fragrances, moisturizers, exfoliating compounds, etc. 

---