Particle deposition in colloid-polymer suspensions: Complex interplay between flow characteristics and polymer interactions

The addition of polymer to the particulate suspension provides several functionalities, such as tuning rheological properties and ensuring uniform dispersion. However, the effect of polymers on particle deposition has not been systematically investigated in the previous literature. In this study, we perform microfluidic observation and image processing analysis of particle deposition in colloid-polymer suspensions, focusing on the interplay between flow characteristics and polymer interactions. Polystyrene particles are selected as model particles, while polyethylene oxide is dissolved in de-ionized water at varying polymer concentrations. Higher polymer concentrations enhance colloidal interactions, as evidenced by zeta potential measurements and depletion interaction analysis. Consequently, in the semi-dilute unentangled regime, increased polymer concentration promotes particle deposit…