SCALABLE PROCESSING OF NANOCOMPOSITES USING PHOTON-BASED METHODS

摘要

Using a modified CVD infusion process and femtosecond laser irradiation, the methods of the present invention demonstrate the ability to create core-shell nanoparticles of metal and metal oxide nanoparticles embedded within the bulk of an optically transparent substrate. With the use of optical masks and multiple precursor chemicals, the inventive methods make it possible to create nanoparticles or core-shell nanoparticles with drastically different compositions in close proximity to each other. Since the mechanism for precursor decomposition is limited to the surface of the nanoparticles within the substrate, it is possible to control the chemistry, size, and shape of nanoparticles within an optically transparent substrate on a nanoscale. The present invention also provides methods of controlling diffusion of a metal or metal oxide precursor compound in a substrate by selectively irradiating the substrate with a wavelength of light which is preferentially absorbed by the substrate and not the precursor, allowing preferential diffusion of the precursor compounds in the irradiated areas.

主权项

1. A method for making a nanocomposite comprising:
a) contacting an optically transparent substrate with an decomposable metal precursor compound such that the decomposable metal precursor compound diffuses into the optically transparent substrate to create a decomposable metal precursor-substrate composite; b) decomposing the decomposable metal precursor-polymer composite of a) and creating a first nanocomposite substrate comprising metal nanoparticles dispersed in the substrate; c) contacting the first nanocomposite substrate of b) with a decomposable metal oxide precursor compound such that the decomposable metal oxide precursor compound diffuses into the first nanocomposite substrate of c) to create a decomposable metal oxide precursor-nanocomposite substrate; and d) selectively exposing one or more discrete areas of the a decomposable metal oxide precursor-nanocomposite substrate of c) to a light source at a wavelength in which the metal nanoparticles of b) in the metal oxide precursor-nanocomposite substrate absorb the laser light at a significantly greater than that the decomposable metal oxide precursor compound in the substrate, at a sufficient pulse width, pulse repetition and sufficient pulse fluence, and for a sufficient period of time to decompose the decomposable metal oxide precursor compound in the metal oxide precursor-nanocomposite substrate to create a nanocomposite comprising a substrate having nanoparticles comprising a metal core and a metal oxide shell in the discrete areas.