Mass transport evolution in microfluidic thin film electrochemical reactors: New correlations from millimetric to submillimetric interelectrode distances
Faidzul Hakim Adnan, Marie‐Noëlle Pons, Emmanuel Mousset
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 ( k m ) (1.61–3.94 × 10 −5 m s −1 ) over a wide range of interelectrode distances ( d elec ) 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 k m for any d elec of interest. Fourthly, under laminar flow (7 < Reynolds ( Re ) < 623) and for temperatures in the range of 10–50 °C (532 < Schmidt ( Sc ) < 3315), new Sherwood ( Sh ) correlations are obtained for both microfluidic and millimetric configurations. It is thus feasible to extrapolate k m for microfluidic electrochemical reactor scale-up.