Fabrication And Characterization Of Several Nanocomposite Materials Based On Gold Nanoparticles

Nanocomposite materials (NCMs) are a relatively new class of materials, which are constructed on a nanometer length scale by the incorporation of several components with different properties. NCMs with unique properties can be designed and fabricated to cater for various particular needs by combining several pure materials. NCMs have received considerable attention in both fundamental and applied research due to their special properties in optics, calorifics, electrics, magnetics, mechanics, chemistry, and so on.Here, based on several pure materials (gold nanoparticles (AuNPs), silica particles, and polystyrene), molecular self-assembly, colloid reduction chemistry, and template-directed technique were used to design and construct a series of gold NCMs. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), reflectometry interference spectroscopy (RIfS), X-ray photoelectron spectrometer (XPS), and UV-visible spectrophotometer (UV-vis) were employed to characterize the resulting gold NCMs. The new optical properties, which are different from those of traditional nanomaterials, can be obtained by controlling and optimizing the compositions and structures of the NCMs. Based on localized surface plasmon resonance (LSPR) of AuNPs and photonic bandgap (PBG) of photonic crystals (PCs), the sensing applications of the gold NCMs including Au/SiO₂, Au@SiO₂, Au/SiO₂-O, and Au/PS-IO were investigated.The major contributions are as follows:1. UV-vis was used to compare the optical properties of AuNPs in various solvents with those of strawberry-like gold nanocomposite particles (Au/SiO₂). The results show that Au/SiO₂ particles without any surfactant could well regenerate optical properties of individual AuNPs. Using Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, a possible mechanism was proposed to qualitatively account for the stability of Au/SiO₂ particles in various solvents.