Molecular configuration of adsorbed cis- and trans-1, 2-ethylene dicarboxylic acids and interparticle forces in colloidal dispersions

Abstract

[Extract] There has not been a study linking the molecular configuration of adsorbed small charged molecules and the interparticle forces in flocculated dispersions. This study will illustrate the linkage with cis- and trans-1,2-ethylene dicarboxylic acids in a 24 vol%R-Al2O3 dispersion. The interparticle forces were evaluated from the yield stress1-8 of the dispersion. The cis-form acid weakens the flocculated network structure by forming a steric layer. The trans-form acid greatly reinforces this structure by bridging at the joints and network junctions. As a result, the dispersion developed a high yield stress and viscosity. This study may give rise to a new family of thickening agents based on small organic molecules that may be of use in products such as toothpaste, printing inks, cosmetics, paints, concrete mix, and paper-coating slurries.