Nanoparticle suspensions were prepared in two PCMs to determine the effect of the addition of nanoparticles on thermal conductivity and expediting freezing. The base PCMs used were cyclohexane and eicosane, and copper oxide nanoparticles were suspended in these hydrocarbons to produce nano-enhanced PCMs (nePCMs). The enhancement of thermal conductivity and expedited freezing were investigated by analytic, experimental, and numerical methods. The thermal conductivity in the liquid phase was significantly enhanced ...
The low-temperature thermoelectric properties of Ca3-xYbxCo4O9+delta systems (x = 0, 0.02, 0.05, and 0.10). It was determined that these systems produced positive thermopower, indicating that the dominant carriers were holes. The electrical resistivity and thermopower were found to increase with increasing Yb3+ content, and the thermal conductivity was found to decrease. The highest calculated thermoelectric figure of merit was 0.037, and this was calculated for the Ca2.95Yb0.05Co4O9+delta sample....
Composite phase change materials were prepared using stearic acid, coffee grounds, and graphite. The coffee grounds were used as a supporting material for the stearic acid, and the graphite was added in an effort to enhance the thermal conductivity of the composite. The composites were characterized by SEM and FT-IR, the thermal conductivity was determined by the phase change temperature and latent heat were determined by differential scanning calorimetry. The ...
PMMA/silica mesocomposites (PSM) and nanocomposites (PSN) were synthesized by incorporating vinyl-modified mesoporous silica (VMS) or silica particles into the poly (methyl methacrylate). The prepared composites were characterized by TEM and GPC. Thermal conductivity and gas permeability measurements were performed on the composites using a thermal constants analyzer and Yanco GTR-31 gas permeability analyzer, respectively. It was determined that an increase in the content of nanoscale silica particles improved the ...
Styrene-butadiene (SBR) was added to high-density polyethylene (HDPE) to form a polymer blend. The thermal conductivity and thermal diffusivity of this polymer blend at room temperature were determined at varying blend compositions. The effects of dynamic crosslinking with sulfur crosslinking system and a mixed system on the thermal conductivity and diffusivity were also investigated. Finally, different models were evaluated for the estimation of thermal conductivity of a two phase system....
