Investigation of the link between micromechanical interparticle bond rigidity measurements and macroscopic shear moduli of colloidal gels

Recent research has been reported on the development of a direct measurement of the particle–particle bond rigidity, κo, between aggregated colloids using a micromechanical three point bending test of assembled linear aggregates employing laser tweezers [J.P. Pantina, E.M. Furst, Colloidal aggregate micromechanics in the presence of divalent ions, Langmuir 22 (2006) 5282–5288]. Current theory suggests how one may use measured κo to estimate bulk colloidal gel shear moduli, G. In cases where the theory is appropriate, direct measurement of κo allows this estimation to be made regardless of the source of interparticle attractions. This work investigates the comparison of G-values computed using the reported κo measurements to values obtained by bulk rheometry. Bulk colloidal gel shear moduli are predicted within a factor of two, and the general trends predicted are observed.