Ben Erné’s research focuses on the physical and colloidal chemistry of electrical double layers. They are essential for the functional properties of soft matter and electrodes, and they consist of opposite charges at the two sides of a liquid-liquid or solid-liquid interface.

[Sources of first 3 images: ACS Macro Lett., J. Phys. Chem. Lett., and ACS Sensors.]

We discovered that electric charge further decreases the ultralow interfacial tension of aqueous-two-phase systems, and using nanoplates, we made the first stable water-in-water emulsions, of interest for research into low-calorie foods.

Thanks to the repulsion between double layers, we made aqueous ferrofluids that remain stable up to 10 teslas. This makes them suitable for the magnetic density separation of plastics, a technology applied at the municipal waste management plant in Amsterdam.

We are continuing to develop a new Donnan-potential-based sensor to measure the electric charge on colloids, proteins, and polyelectrolytes, a key property for the performance of paints, foods, and baby diapers, among other soft matter.

We are also working on a new calorimetric approach to characterize the electrical double layer inside the (1 nm wide) micropores of porous electrodes. Such electrodes are used in supercapacitors (for electrical energy storage) and capacitive deionization (to make drinking water from salt water). We recently demonstrated that such measurements inform about the attraction of the ions to the electrode surface and the average electric potential inside the pores.