Like-charge interactions between colloidal particles are asymmetric with respect to sign.

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.

SUBMITTER: Gomez EW 

PROVIDER: S-EPMC4161288 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature