Effect of CsxWO 3 Nanoparticles Content and Atomic Ratio for Near Infrared Cut-off Characteristics
In this work, the ceramic nanocomposites films with homogeneous dispersions of tungsten bronze nanoparticles with ternary additive cesium have been prepared by mixing Urethane acrylic/UVcoating binder and dispersed sol depending on the atomic ratio and the particle contents. Furthermore, we are synthesized the CsxWO3 with different annealing at 700, 800, and 900 °C in an N2 gas for 1 hr respectively. The structure and sizes of ceramic particles was observed XRD and PSA spectrometer, the heat-shielding properties of their films were investigated by NIR spectrometer. Synthesized Cs0.33WO3 particles with annealing at 800 °C typically formed hexagonal tungsten bronze structure for good absorption of NIR, size observed as being 30-100 nm and <150 nm. Especially, remarkable absorption of NIR wavelength ranges makes ceramic composite films good candidate for use as a heat shielding window, it clearly shows useful for applications where heat shield is required.
Near Infrared Absorption of Tungsten Oxide Nanoparticle Dispersions
Homogeneous dispersions of reduced tungsten oxide and tungsten bronze nanoparticles with ternary additives Na, Tl, Rb, and Cs have been prepared in the wet process and examined for optical properties. The dispersions of reduced tungsten oxide and tungsten bronze nanoparticles are found to show a remarkable absorption of near infrared light while retaining a high transmittance of visible light. This property is highly suitable for solar control filters in automotive and architectural windows.
Shape Modulation of Tungstic Acid and Tungsten Oxide Hollow Structures
Tungstic acid (H2W1.5O5.5·H2O) hollow structures, including hollow spheres, nanotubes, and hollow boxes, have been selectively synthesized by a nonaqueous and surfactant-free solvothermal method. The synthesis involves the alcoholeysis of WCl6 in the presence of urea. A series of experimental factors such as the urea amount, ethanol amount, reaction temperature, reaction time, and pH value have important influences on the morphology and size of the products on the basis of scanning electronic microscopy and X-ray powder diffraction characterizations. The subsequent slow annealing leads to the formation of tungsten oxide (WO3), the hollow morphology of which is well-retained. The most striking feature of these WO3 hollow structures is the resultant nanoporous walls or shells, which may lead to potential applications in many fields, including energy storage, catalysis, and biotechnology.