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Updated: May 25, 2026

Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy
Published on: July 18, 2014
Beyond Millikan: the dynamics of charging events on individual colloidal particles
Filip Beunis1, Filip Strubbe, Kristiaan Neyts
1Ghent University-Electronics and Information Systems, Sint-Pietersnieuwstraat 41, 9000 Ghent, Belgium.
Abstract:
By measuring the stable charge on oil drops in air, Millikan demonstrated the discrete nature of electric charge. We extend his approach to the charge on solid-liquid interfaces, and focus on the dynamics of the discrete fluctuations. Our measurements are accurate and fast enough to observe changes of one elementary charge. Experiments over thousands of seconds yield information about the fast dynamics of electrochemical reactions, relevant for physicochemical and biological systems. As an example, we study (dis)charging processes on colloidal particles in a nonpolar liquid.
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