Review on surface charge

Post date: Aug 24, 2018

Anne-Laure, Li, Oriane and Laurent, with colleagues from Delft and Montpellier, have just published an invited review entitled "Measuring surface charge: why experimental characterization and molecular modeling should be coupled" in Current Opinion in Colloid and Interface Science.

Surface charge controls many static and dynamic properties of soft matter and micro/nanofluidic systems, but its unambiguous measurement forms a challenge. Standard characterization methods typically probe an effective surface charge, which provides limited insight into the distribution and dynamics of charge across the interface, and which cannot predict consistently all surface-charge-governed properties. New experimental approaches provide local information on both structure and transport, but models are typically required to interpret raw data. Conversely, molecular dynamics simulations have helped showing the limits of standard models and developing more accurate ones, but their reliability is limited by the empirical interaction potentials they are usually based on. This review highlights recent developments and limitations in both experimental and computational research focusing on the liquid-solid interface. Based on recent studies, the authors make the case that coupling of experiments and simulations is pivotal to mitigate methodological shortcomings and address open problems pertaining to charged interfaces.

In relation to the NECtAR project, this article highlights the complex relation between the surface charge and the response to electric, osmotic and thermal gradients, controlling the performance of nanofluidic systems for energy conversion. Moreover, it shows that predictive understanding on this matter can only be achieved through coupling between experimental characterization and molecular modeling, i.e. our approach of choice in the NECtAR project.