Microfluidic in-line dynamic light scattering with a commercial fibre optic system
Luis M. G. Torquato, Nelson Hélaine, Yufan Cui, Róisín O’Connell, Jérémie Gummel, Eric S. J. Robles, David Jacob, João T. Cabral
Abstract
), and considerations of the relative contribution of 'transit' and 'Brownian' terms enable the identification of regions where (i) a quiescent approximation suffices, (ii) the flow-DLS framework holds, as well as (iii) where deviations are found, until eventually (iv) the convection dominates. We investigate practically relevant, robust setups, namely that of a capillary connected to microdevice, as well as direct measurement on a glass microdevice, examining the role of capillary dimensions and challenges of optical alignment. We conclude with a demonstration of a continuous flow measurement of a binary surfactant/salt solution, whose micellar dimensions vary with composition, characterised with hundreds of data points (every ∼5 s) and adequate statistics, within a few minutes.