Factors influencing the stability of the 2-hydroxyethyl cellulose/alumina system

Hydroxyethyl cellulose (HEC) is widely used in many branches of industry such as paint, textile, cosmetics and mineral industries. Commercially used products, besides HEC, very often contain solids and surfactants. However, the mechanism of HEC adsorption on the metal oxide surface as well as the stability of the HEC/alumina suspensions have not been fully explained. In this paper the influence of such factors as the polymer concentration (20–500 ppm), pH of the solution (3; 6 and 9), ionic strength of the background electrolyte (0.001; 0.01 and 0.1) as well as the presence of some surfactants (SDS, CTAB, TX-100) on the adsorption and the stability of the colloidal suspensions was determined. The obtained results were discussed together with those from the zeta potential measurements. All the obtained results show that there are two ways to improve the stability of studied suspensions. One of them is the addition of 500 ppm of HEC. The phenomenon responsible for the stabilization is the steric stabilization caused by the repulsion between the colloidal particles covered with the high molecular weight substance. Then the other way is the usage of the mixture of 100 ppm of HEC with an ionic surfactant (CTAB or SDS). In this case stabilization is the effect of the presence of charge coming from the surfactant molecules. The obtained results are very promising in the fields of functionalized materials such as adsorbents and catalysts.