Mass transport evolution in microfluidic thin film electrochemical reactors: New correlations from millimetric to submillimetric interelectrode distances

Abstract Correlation of the mass transfer characteristics of microfluidic parallel-plate electrochemical reactors is proposed for the first time. Firstly, the variation in the mass transfer coefficient (km) (1.61–3.94 × 10−5 m s−1) over a wide range of interelectrode distances (delec) from millimetric (3 mm) to micrometric values (100 µm) is reported. Secondly, a drastic slope change in the curve makes it possible to identify the onset of microfluidic behavior in a quantitative way for the first time, i.e. below a 1000 µm gap. Thirdly, a mathematical model is proposed which predicts km for any delec of interest. Fourthly, under laminar flow (7