The thermal properties of nanomaterials have seen slower progress due to the challenges of experimentally measuring and controlling thermal transport at the nanoscale. At the nanoscale, the dimensions of nanostructures are comparable to the mean free path and wavelengths of heat carrying photons at room temperature. Nanomaterials are being explored for applications such as improved insulation materials, higher resolution displays using nanophosphors, high-power magnets, aerospace components requiring enhanced performance at high temperatures, future weapons platforms, nanofluids for enhanced thermal transport, and multilayer thin films for applications such as thermal barriers and thermoelectric power generation.

1. INTRODUCTION
The thermal properties of nanomaterials have only
seen slower progresses. This is partially due to the difficulties of
experimentally measuring and
controlling the thermal transport in nano scale dimensions. The heat
carrying photons often have large wave vectors and mfp in
the order of nanometer range at room temperature, so that the
dimensions of the nanostructures are
comparable to the mfp and wavelengths of photons. For macroscopic
systems, the
dimension is large enough to define a local temperature in each
region within the materials and this
local temperature will vary from region to region, so that one can
study the thermal transport
properties of the materials based on certain temperature
distributions of the materials.

2. Better Insulation Materials
Aerogels are currently being used for insulation in
offices, homes, etc. By using aerogels for insulation,
heating and cooling bills are drastically reduced,
thereby saving power and reducing the attendant
environmental pollution. They are also being used as
materials for "smart " windows, which darken when
the sun is too bright (just as in changeable lenses in
prescription spectacles and sunglasses) and they
lighten themselves, when the sun is not shining too
brightly.

3. Phosphors for High-Definition TV
Nanocrystalline zinc selenide, zinc sulfide, cadmium
sulfide, and lead telluride synthesised by the sol-gel
techniques are candidates for improving the
resolution of monitors. The use of nanophosphors is
envisioned to reduce the cost of these displays so as
to render high-definition televisions (HDTVs) and
personal computers affordable to be purchased by an
average household.

4. High-Power Magnets
Typical applications for these high-power rare-earth
magnets include quieter submarines, automobile
alternators, land-based power generators, motors for
ships, ultra-sensitive analytical instruments, and
magnetic resonance imaging (MRI) in medical
diagnostics.

5. Aerospace Components with Enhanced
Performance Characteristics
• In spacecrafts, elevated-temperature strength
of the material is crucial because the
components (such as rocket engines,
thrusters, and vectoring nozzles) operate at
much higher temperatures than aircrafts and
higher speeds. Nanomaterials are perfect
candidates for spacecraft applications.

6. Better and Future Weapons Platforms
• Conventional guns, such as cannons, 155 mm
howitzers, and multiple-launch rocket system (MLRS),
utilise the chemical energy derived by igniting a charge
of chemicals (gun powder). The maximum velocity at
which the penetrator can be propelled is approximately
1.5-2.0 km/sec. On the other hand, electromagnetic
launchers (EML guns), or railguns, use the electrical
energy, and the concomitant magnetic field (energy),
to propel the penetrators/projectiles at velocities up to
10 km/sec. This increase in velocity results in greater
kinetic energy for the same penetrator mass. The
greater the energy, the greater is the damage inflicted
on the target.

7. NANO FLUIDS
• The use of nanofluid to enhance the thermal
transport is another promising application of the
thermal properties of nanomaterials. Nanofluids are
generally referred to the solid-liquid composite
materials, which consist of nanomaterials of size in
the range 1-100nm suspended in a liquid. They have
high thermal conductivities and adsorption
properties hence use in cooling systems.

8. MULTI-LAYER THIN FILMS
• For example, multilayer thin films can be used
as thermal barriers at high
• temperatures environments, such as in
engines to improve their efficiencies; epitaxial
superlattices of semiconductor films with low
thermal conductivity can be used in
thermoelectric power generation