Investigation of Carboxymethyl Cellulose Adsorption on a Model Charged Interface

ABSTRACT

This report concerns electro-optical study of colloid-polyelectrolyte complexes of sodium carboxymethyl cellulose (NaCMC) and gamma-aluminium oxide (γ-Al₂O₃) at pH 6.0 and fixed ionic strength. A frequency plateau shrink and a shift towards lower frequencies were observed after NaCMC adsorption especially near the point of zero charge. The electro-optical effect dependence on electric field strength shows that the coated particles reach full orientation at lower values of the applied electric field than particles with the highest charge density, previously investigated. Electrophoretic measurements, used as an additional analysis of the changes in the suspensions, showed particles' charge overcompensation above 1.10⁻³ g/L NaCMC and a saturation of electrophoretic mobility at the highest investigated concentrations of the polymer.

Keywords:

• adsorption
• colloid
• electro-optics
• interface
• polyelectrolytes