Thermal Conductivity Resources

Top 10 Low Thermal Conductivity Research Papers

  1. Noble-gas-infused neoprene closed-cell foams achieving ultra-low thermal conductivity fabrics

    Closed cell foams are widely used as protective garments in extreme environments. This article studied the use of neoprene-based materials in wetsuits by developing a strategy for reducing the thermal conductivity of a flexible, closed cell polychloropene foam. The thermal conductivities of the charged and unmodified neoprene foams were measured using the transient plane source (TPS) method with the Hot Disc TPS 2500 S thermal conductivity meter. It was found that a wetsuit made of ultra-low thermally conductive neoprene capable of potentially extending dive times to 2–3 hours in water below 10 °C, compared with <1 hour for the state-of-the-art wetsuits.

  2. Preparation of porous mullite ceramics with low thermal conductivity

    This study analyses a mullite ceramic formed through foaming and starch consolidation of mullite powder, and how its thermal conductivity changes with porosity of the ceramic. The thermal conductivity was measured through the Hot Disc transient plane source (TPS) method with the TPS 2500 S. As the porosity of the mullite ceramic increases so does the thermal conductivity.

  3. Superlow Thermal Conductivity 3D Carbon Nanotube Network for Thermoelectric Applications

    A 3D carbon nanotube (CNT) network is explored and how potassium or iodine doping can affect the thermoelectric properties of this network. Through in-situ nanoscaling, this CNT network was combined with polyaniline (PANI) and increased the thermoelectric performance of PANI while maintaining the flexible structure of the 3D CNT network. This composite has one of the lowest thermal conductivities of any reported CNT materials.

  4. Low thermal conductivity and enhanced thermoelectric performance of nanostructured Al-doped ZnTe

    This article investigates the effect of aluminum doping on the thermal conductivity and other thermoelectric properties of nanostructured Zn1•XAlXTe (0 ≤ X ≤ 0.15) for a temperature range of 300 K – 600 K. The thermal conductivity was measured using the transient plane source (TPS) technique by a Hot Disc thermal constants analyzer. It was found that with increasing doping of aluminum, the thermal conductivity decreased, and with increasing temperature thermal conductivity also decreased. The decreasing of thermal conductivity increased the performance of the thermoelectric material expressed by the dimensionless figure of merit (zT).

  5. Low thermal conductivity and rapid synthesis of n-type cobalt skutterudite via a hydrothermal method

    Researchers are currently developing ways to produce thermoelectric materials, such as skutterudites, with low lattice thermal conductivity. In this paper, a hydrothermal synthesis procedure was developed to fabricate CoSb3 compounds. A Hot Disc thermal constant analyzer measured the thermal conductivity of three CoSb3 samples using the transient plane source (TPS) method. Results showed that thermal conductivity increased with decreasing temperature, and was much lower for the hydrothermal-synthesized CoSb3 samples than other fabrication methods.

  6. Preparation of Monolithic Silica Aerogel of Low Thermal Conductivity by Ambient Pressure Drying

    Monolithic silica aerogels were synthesized with very low thermal conductivity (0.036 W/mK) and high porosity (97%) via ambient pressure drying. This method of drying replaces supercritical drying which is more costly and dangerous. The aerogel was derived from tetraethoxysilane (TEOS) and treatment with trimethylchlorosilane. NMR and FT-IR spectroscopy were used for characterization of surface bonding and contact angles. Using the multiple surface modification (MSM) method allowed the authors to generate an aerogel with high monolithicity and porosity, as well as low thermal conductivity.

  7. Porous mullite ceramics with low thermal conductivity prepared by foaming and starch consolidation

    Using industrial grade mullite powder and a foaming and starch consolidation process, a series of porous mullite ceramics were prepared. These ceramics were analyzed by a Hot Disc thermal constants analyzer, and it was determined that the ceramics had low thermal conductivities and would make good thermal insulators. The porosity of the synthesized ceramics can be controlled by the sintering temperature and by adjusting solid loading. The ceramics were subjected to theoretical models (Eucken-Maxwell and EMT) in order to prove that the prepared ceramics were classified as ‘internal porosity.

  8. Low Thermal Conductivity Coatings for Gas Turbine Applications

    Thermal barrier coatings (TBC) are plasma sprayed onto gas turbine parts in order to improve combustion efficiency and component life time. Two TBC are looked at in this report: yttria partially stabilized zirconia (YPSZ) and dysprosia partially stabilized zirconia (DyPSZ). Both the TPS and laser flash techniques were used to measure the thermal conductivity of the coatings and the results were compared. In addition the effect of barrier microstructure on thermal conductivity was investigated.

  9. Enhanced thermoelectric performance of compacted Bi0.5Sb1.5Te3 nanoplatelets with low thermal conductivity

    A series of compacted Bi0.5Sb1.5Te3 nanoplatelets are synthesized using hydrothermal methods, followed by cold pressing and sintering at temperatures between 300°C and 380°C. A variety of thermal, mechanical and electrical analyses are then performed on the synthesized nanoplatelets including: TPS technique for thermal conductivity, SEM/TEM/AFM to elucidate the mechanical and physical properties of the nanoplatelets, and the Oxford closed cycle cooler cryostat for measurement of electrical resistivity. The nanoplatelet sample that was sintered at 340°C resulted in the best combination of thermal, electrical and mechanical properties.

  10. Thermal conductivity and dispersion stability of copper oxide nanofluid in kerosene

    Kerosene is used as a coolant in engines, however like many conventional heat transfer fluids, it has a low thermal conductivity. Nanofluids are suspensions of thermally conductive nanometer sized particles in a base fluid. This paper explores the thermal properties of a Kerosene based nanofluid with copper oxide (CuO) nanoparticles. The thermal conductivity meter (TPS-500) measured the thermal conductivity of copper oxide/Kerosene nanofluids using the transient plane source (TPS) technique. Nanofluid samples of 60 ml ranging from 0.01-0.08% concentration were measured for 20 seconds at 25mW. Results showed that the thermal conductivity of the CuO/Kerosene nanofluid increased with CuO concentration up to a certain point, then slightly declined.