Measuring the surface potential and isoelectric point of polyester fibres with a zeta potential analyzer

courtesy of DataPhysics

Polyester fibres are synthetic fibres manufactured from polyethylene terephthalate. Polyester fibres are widely used in the textile industry. However, unmodified polyester fibres have deficiencies, e.g., a low water uptake, a hydrophobic character, and few reactive groups. This means they display a low affinity for dyes. Many techniques for improving the reactivity and hydrophilic character of polyester fibres exist in an industrial context. Generally, modifying fibres can enhance the interactions between the cations or anions of the dye and the functional groups on the fibre surface, and thus, the dyeability and water sorption of such fibres[1].

To track and analyse changes when developing new or enhancing existing fibre modification techniques, a sensitive measurement method is needed. A zeta potential measurement is a very powerful way to study the properties of surfaces[2]. It is able to evaluate the nature and dissociation of functional surface groups, and supplement contact angle measurements with additional information about the characteristics of the solid surface. Additionally, a zeta potential measurement is also able to evaluate the adsorption of ions and molecules. The ZPA 20 zeta potential analyzer from DataPhysics Instruments (Fig. 1) can measure the zeta potential of fibres, powders, and plate-shaped surfaces by means of a bidirectional streaming potential or streaming current technique. In this application note, we use the ZPA 20 to study the electrical properties and functional groups at the surface of polyester fibres.Get the complete application note here