Analytical model for surface charge property of pH-regulated nanorods

An analytical model for the zeta potential and the surface charge density of pH-regulated nanorod particles is derived for the first time. This extends existing models by taking account of the effects of multiple ionic species, surface chemistry reactions, Stern layer, and surface curvature, all of practical significance. Our model predicts excellently the experimental data in the literature for the zeta potential of 11-mercaptoundecanoic acid functionalized gold nanorod. The validated analytical multi-ion model provides valuable information for applications involving pH-tunable nanorods. ? 2014 Elsevier B.V.