Measuring Interfacial Polymerization Kinetics Using Microfluidic Interferometry

A range of academic and industrial fields exploit interfacial polymerization in producing fibers, capsules, and films. Although widely used, measurements of reaction kinetics remain challenging and rarely reported, due to film thinness and reaction rapidity. Here, polyamide film formation is studied using microfluidic interferometry, measuring monomer concentration profiles near the interface during the reaction. Our results reveal that the reaction is initially controlled by a reaction–diffusion boundary layer within the organic phase, which allows the first measurements of the rate constant for this system.