Nanoscale Surface Strategies for Reducing Foulant Adhesion in Emulsion Polymerization

Emulsion polymerization is widely implemented for producing sustainable waterborne polymer dispersions for diverse applications such as paints, adhesives, and synthetic rubbers. However, fouling during emulsion polymerization reduces heat transfer, increases reactor downtime, and severely affects product quality. While previous studies have focused on suppressing fouling by inhibiting the polymerization reactions on reactor surfaces, strategies for mitigating foulant adhesion have not yet been explored. In fact, foulant adhesion is known as one of the primary mechanisms for fouling in emulsion polymerization. To address this issue, we developed a series of durable ultrathin copolymer coatings via initiated chemical vapor deposition and investigated the relationship between the surface properties and the adhesion to latex foulant. We found a transition between two adhesion mechanisms that determines the design strategies for antifouling coatings: in the dry adhesion regime, reducing surface polarity decreases the adhesion; in the hydration repulsion regime, hydrophilicity is key to minimize foulant adhesion. Our copolymer coatings exhibit up to 270% smaller work of adhesion than Fe and 71.8% lower surface foulant density than stainless steel in simulated fouling assessments, showing promising performance for fouling control in emulsion polymerization.