Optical Properties of Au-SiO₂ Core-Shell Colloids

Luis M. Liz-Marzán
Departamento de Química Física e Química Orgánica
Universidade de Vigo
Apdo. 874
36200 Vigo
Spain

E-mail: lmarzan@univigo.es

ABSTRACT

A rather complete description is given of the optical properties of both dilute and concentrated dispersions of core-shell particles where the core is gold, and the shell is silica. In the first part, we focus on the influence of the thickness of the silica shell, as well as the effect of the refraction index, on the uv-visible spectra of the colloid. Then we study the effect of temperature, both in water and ethanol, and finally we show how for concentrated dispersions there is a rich, concentration dependent optical behaviour.