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Updated: Apr 23, 2026

Quantitative and Qualitative Examination of Particle-particle Interactions Using Colloidal Probe Nanoscopy
Published on: July 18, 2014
Like-charge interactions between colloidal particles are asymmetric with respect to sign
Esther W Gomez1, Nathan G Clack2, Hung-Jen Wu3
1Department of Chemical Engineering, University of California, Berkeley, CA, 94720, USA ; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Abstract:
Two-dimensional dispersions of colloidal particles with a range of surface chemistries and electrostatic potentials are characterized under a series of solution ionic strengths. A combination of optical imaging techniques are employed to monitor both the colloid structure and the electrostatic surface potential of individual particles in situ. We find that like-charge multiparticle interactions can be tuned from exclusively repulsive to long-range attractive by changing the particle surface composition. This behavior is strongly asymmetric with respect to the sign of the surface potential. Collective long-range attractive interactions are only observed among negatively charged particles.
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