Particle Size Effects on Surface Charge and Charge Regulation in O/W Nanoemulsions

• Applicant: Professor Dr. Björn Braunschweig
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 409537869

Nanoscale properties at interfaces, play a key role in the colloidal stability of emulsions and other soft matter materials where physical properties need to be controlled from the nano to macroscopically visible length scales. In this project we address open questions that deal with the connection between the critical charge, its coupling to the particle size (<200 nm) and its role on the interface adsorption of surfactants in nanoemulsions. We plan to use photoswitchable surfactants that can change their surface activity on demand and can be applied to modify the o/w interfaces without largely altering the chemical composition (concentration, ionic strength, pH etc.) of the bulk. This will enable us to study ion condensation and interface charging in o/w nanoemulsions using SHS spectroscopy in unprecedented detail, but will also offer additional scientific merit where we investigate nanoemulsion with responsive properties like remote control of particle size distribution and charge triggered by light irradiation.

• DFG Programme: Research Grants