Effect of the Solution Refractive Index on the Color of Gold Colloids

Abstract

Aqueous gold sols with a mean diameter of 16 nm have been transferred into various mixtures of organic solvents with different refractive indices using a polymeric comb stabilizer to prevent colloid coagulation. The sols change color from red to purple depending on the refractive index of the solvent. The optical properties of the sols in the different media are in excellent agreement with the predictions of Mie theory. © 1994, American Chemical Society. All rights reserved.