Rheology

Colloid Viscoelasticity Study

Colloidal particles can aggregate into three-dimensional network structures to form colloidal gels. Due to the poor adhesion between particles, the colloidal gel is prone to yield under the action of external force, and once the external force disappears, it can automatically return to its original state. The gelling point of a colloidal gel depends not only on the particle concentration, but also on the strength of the interactions between the particles. The network-like aggregated structure of colloidal gels can be directly observed by fluorescence microscopy. Colloidal gel systems are promising systems for medical and industrial applications.

Fig.2 Rheological aspects of colloidal gels in thermoresponsive microgel suspensions.^[1]

Colloid Rheological characterization

Understanding the rheological behavior of colloidal suspensions is important for analyzing and controlling the properties of colloidal materials. For silica nanoparticles, for example, rheological characterization can be used to predict the suitability of suspensions for mechanical properties in energy absorption and damping materials. For soft colloids such as star polymers, vesicles, and even cells, rheological characterization of their suspensions can reveal the trough-like walking and tumbling motions of individual particles in solution, as well as the shearing of semi-dilute suspensions. Thinning behavior is two common properties of all soft colloidal suspensions.

Fig.1 Dynamic shear rheology of colloidal suspensions of surface-modified silica nanoparticles in PEG.^[2]

What Can We Do?

• Alfa Chemistry can design exclusive colloidal rheology research solutions according to customer needs to solve any related problems that customers want to know.
• The comprehensive rheological analysis equipment equipped by Alfa Chemistry can provide professional technical guidance to help customers complete relevant analysis.
• Alfa Chemistry provides directions and solutions for the improvement of colloid properties by helping customers analyze the rheological behavior of colloids.

References

1. Minami S, et al. Rheological aspects of colloidal gels in thermoresponsive microgel suspensions: formation, structure, and linear and nonlinear viscoelasticity - ScienceDirect. Current Opinion in Colloid & Interface Science. 2019.
2. Swarna, et al. Dynamic shear rheology of colloidal suspensions of surface-modified silica nanoparticles in PEG. Journal of Nanoparticle Research. 2017.
3. Winkler R G ,  Fedosov D A ,  Gompper G . Dynamical and rheological properties of soft colloid suspensions[J]. Current Opinion in Colloid & Interface Science, 2014, 19(6):594-610.

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