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One of the largest current uses of nanopowders is for modifying the
properties of polymers. The tire uses more nanopowders than any
other application, where flame-made carbon black and silica enhance
the life, strength, and traction of the starting rigid polymer.
nGimat's new composition can be blended into various polymers and
other organic media to yield polymers with ever-lasting color,
conductivity, wear, optical index, biocidal properties, catalytic
properties, capacitance, or other desired properties. Key to
enabling use is affordability and proper surface functionality so a
quality composite is formed.
In cosmetic applications, doped TiO2 and doped ZnO are being
developed for use in sunscreens for sensitive skin, baby products
and specialty applications. Most of today's topical medications
that protect against solar radiation contain organic chemical
compounds that absorb ultraviolet light and opaque materials that
reflect light (usually metallic oxides). The organic active agents
may cause skin irritation and other side effects while the currently
used particles are white until rubbed thin. Newer
nano-sized reflecting powders provide broad-spectrum protection
against UV radiation and are more cosmetically acceptable because
they are flesh-toned and turn invisible when applied. nGimat will provide doped
inorganic nanoparticle materials that provide increased safety,
appearance and UV blocking compared to simple inorganic materials.
nGimat has already developed reactors and processing techniques
enabling control of nanomaterial size, crystallinity and other
properties.
In pigment applications, several nano-size pigments with complex
compositions have been demonstrated using the cost-effective
NanoSpraySM Combustion Processing technology for manufacturing
particles with controlled properties and size distribution. This
technology enables optimization of pigments, not only for color, but
also for additional functional properties such as electrical or
thermal conductivity, infrared radiation reflectivity (to reduce
heat build up), advanced camouflage capabilities (signature
tailoring), and corrosion resistance. The technology also enables
flexibility in selection of materials system through modification of
liquid solution chemistry, reduction in operating and capital costs,
scalability, particle size control (down to vapor and nano-scale),
and improved uniformity.
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Electron microscopic images of nGimat's suncreen nanopowders
and blue nanopigments |
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nGimat's nanopigments |
nGimat has techniques to produce polymer and inorganic/organic
composite particles and to modify surface properties of particulate
matter by encapsulating them with thin films in dynamic flow-through
reactors and in fluidized beds. nGimat's
NanoSpraySM-based technology dynamically combines the
three-step process of production, encapsulation, and dispersion of
coated nanoparticles into a one-step process that can naturally
surface treat nanoparticles during their synthesis and disperse them
under controlled conditions. Through control of flame temperature,
stoichiometry, and flow configuration, various combinations of
particle and coating material can be achieved. The figure below
shows an SEM micrograph of NanoSpray Process-produced polymer
particles that contain inorganic nanoparticles. Similar results have
been obtained when producing pure polymer particles. The polymer
particles are spherical and smooth with estimated diameters of about
5 microns. The figure below also shows ZnO nanoparticles coated with
a SiO2 layer formed using a dynamic flow-through gas process.
Several other combinations of nanoparticle and coating materials
have been demonstrated, and the resulting nanomaterials have shown
good performance in functional testing.
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NanoSpray Process-produced polymer powder
containing inorganic particles and image of ZnO nanoparticle
encapsulated with SiO2 layer |
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