@article {1439,
	title = {Like-charge interactions between colloidal particles are asymmetric with respect to sign.},
	journal = {Soft Matter},
	year = {2009},
	month = {2009},
	pages = {1931-6},
	abstract = {<p>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 <em>in situ</em>. 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.</p>
},
	author = {Clack, Nathan G and Salaita, Khalid and Wu, HJ and Groves, JT and Gomez, EW}
}
