Spontaneous deposition of gold nanoparticle nanocomposite on polymer surfaces through sol-gel chemistry

A aminosilica nanocomposite layer containing a monolayer of gold nanoparticles (d = 18-22 nm) with a well-defined spacing was spontaneously deposited on an unmodified polystyrene surface via a sol-gel reaction when the reduction reaction was carried out under 1:8 molar ratio (gold(III):aminosilane). The amount of aminosilica and spacing between gold nanoparticles were found to be a function of the aminosilane:water molar ratio, which contributes to the plasmonic property of the films with its absorption wavelength ranging between 701 and 548 nm. Furthermore, the nanocomposite film that consists of a monolayer of nanoparticles in aminosilica has also been deposited on the surface of polystyrene beads. This core-shell structure was found capable of storing electrostatic charges and forming a well-separated 2D array.