Au/Titania Composite Nanoparticle Arrays with Controlled Size and Spacing by Organic-Inorganic Nanohybridization in Thin Film Block Copolymer Templates

Abstract

A simple approach to prepare arrays of Au/TiO 2 composite nanoparticles by using Au-loaded block copolymers as templates combined with a sol-gel process is described. The organic-inorganic hybrid films with closely packed inorganic nanodomains in organic matrix are produced by spin coating the mixtures of polystyrene-block-poly(ethylene oxide) (PS-b-PEO)/HAuCl 4 solution and sol-gel precursor solution. After removal of the organic matrix with deep UV irradiation, arrays of Au/TiO 2 composite nanoparticles with different compositions or particle sizes can be easily produced. Different photoluminescence (PL) emission spectra from an organic-inorganic hybrid film and arrays of Au/TiO 2 composite nanoparticles indicate that TiO 2 and Au components exist as separate state in the initial hybrid film and form composite nanoparticles after the removal of the block copolymer matrix.

Comparison of UV Irradiation and Sintering on Mesoporous Spongelike ZnO Films Prepared from PS-b-P4VP Templated Sol–Gel Synthesis

“…After spin-coating the solution onto a cleaned silicon (100) or glass substrate (Figure d), annealing is performed to improve the self-assembly of the nanostructure (Figure e). High-temperature sintering (Figure f) and UV irradiation (Figure g) are used to efficiently remove the polymer template and to obtain mesoporous ZnO films (Figure h). ,,− , Fourier-transform infrared spectroscopy (FT-IR) is used to determine the residual PS- b -P4VP after template removal. It is shown in Figure S1 that the polymer template is removed completely for ZnO films treated with either sintering or UV irradiation as compared with the ZnO/PS- b -P4VP composite films before template removal.…”

“…In the literature, the strain changes of mesoporous ZnO structures after organic surfactant decomposition via ultraviolet (UV) irradiation and thermal annealing were compared to accurately calculate the strain change in the ZnO crystallization process . In general, UV irradiation and high-temperature sintering are two commonly used methods for the diblock copolymer removal from polymer–metal oxide composite films prepared via sol–gel synthesis. ,,− During UV irradiation or sintering, the polymer template is removed. The initial hybrid films turn into an inorganic one which has a mesoporous thin film morphology.…”