Polystyrene/multi-walled carbon nanotube (PS/MWCNT) nanocomposite foams were prepared in order to determine if these foams exhibited a reduced thermal conductivity in comparison to pristine polystyrene foam. The thermal conductivity of foams can be broken down into three modes of conduction: gas conductivity, solid conductivity, and radiative conductivity. The PS/MWCNT foams had decreased gas and radiative conductivities in comparison to the pristine PS foam; however, the solid conductivity ...
Carbon foams were prepared from diphenolic acid-based benzoxazine foams by pyrolysis under nitrogen atmosphere. The method used in this article produced foams containing a large fraction of closed cells which is uncommon for carbon foams. The foams studied were found to possess similar mechanical properties common to other carbon foams; however, the presence of the high fraction of closed cells led to the lowest observed thermal conductivity ever reported for ...
The potential for the use of silica aerogels doped with TiO2 nanowires as thermal insulators was evaluated. It was found that the TiO2-doped aerogels showed good thermal insulation properties and that other desirable properties were retained upon the addition of TiO2 nanowires....
Very porous ceramics were prepared by the direct foaming method containing 79% kaolinite , based on commercial clay. Ceramics were prepared with different pore volume fractions, and the different ceramics were analyzed using the transient plane source (TPS) technique to measure thermal conductivity. Increasing pore volume fraction led to decreased thermal conductivity....
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 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 ...
