Using Greener Gels To Explore Rheology

A laboratory experiment was developed to investigate the rheological properties of a green calcium-cross-linked alginate gel as an alternative to the traditional borax-cross-linked poly(vinyl alcohol) gel. As borax is suspected of damaging fertility and the unborn child, a safe, green alternative is necessary. The rheological properties of a sodium alginate solution were examined as a function of temperature using capillary viscometry. Gelation and degelation processes were followed using rotational viscometry. The non-Newtonian shear-thinning properties were also exemplified by determining the viscosity as a function of spindle speed using the rotational viscometer. Students making the transition from a first- to second-year undergraduate chemistry program within a natural sciences degree have successfully conducted this laboratory experiment.