Authors: S. Badilescu, M. Kahrizi, P.V. Ashrit and V-V Truong
Affilation: Concordia University, Canada
Pages: 293 - 296
Keywords: nanostructures, gold composites, plasmon resonance
Composite films have been prepared in one step by a vertical deposition method from the aqueous suspension of gold colloids and polystyrene (PS) microspheres. The composite is formed on a glass substrate by convective assembly from the evaporating meniscus of the suspension. Au-PS composite films appear opalescent and SEM observations have shown that the structure of the composite is partially ordered. The film is “stripe”structured and made of close-packed PS microspheres separated by narrow (around 500 nm in diameter)gold filaments. The formation of filaments is accounted for by the strong van der Waals forces between the Au particles. The presence of filaments is confirmed by the plasmon resonance band in the 690-736 nm region. The non-uniform self-assembly is accounted for by the disrupting effect of the Au nanoparticles. The structure of the composite prepared by the vertical deposition method is compared to that of ready made template infiltrated by Au by a chemical or electrochemical method. A macroporous gold film made of evenly spaced 500 nm wide filaments is obtained from the composite after the removal of PS by dissolution in toluen. The fabrication of both composites and macroporous gold films by this method is easy and no additional equipment is necessary. The macroporous gold films may find a range of applications such as catalytic and SERS supports, optical and decorative coatings.