Monitoring oxidation of cellulose fibers using zeta potential measurements

Oxidation of cellulose fibers is usual procedure for surface cleaning and introducing new functionalities in their structure. Due to the presence of three hydroxyl groups on each glucopiranose unit, cellulose is very susceptible to oxidation. The most desirable and positive effect of oxidation is introduction of acidic carboxyl groups in cellulose structure. Acidic groups contribute to the surface charge of fibers and have influence on streaming potential of fibers. In this work cellulose fibers (cotton and viscose) with different amounts of COOH groups were prepared via oxidation with KMnO4, NaIO4 and NaClO2 under various treatment conditions. Carboxyl group content and zeta potential measurements were carried out in order to investigate influence of acidic groups’ quantity on surface charge of fibers. Results could help to anticipate how processing technique such as oxidation would influence further textile fibers processing, since surface charge is directly related to the reactivity of cellulose to a different agents, e.g. dyes, finishing agents, drug compounds for wound treatment, etc