This research studied the effect of the addition of vinyl-modified silica and raw silica additions to polymer-silica nanocomposite foams. Extensive physical property characterization was undertaken after their addition to quantify their influence. TEM found that silica particles added through the vinyl-modified silica dispersed better than the raw silica. This created foams with a higher density and smaller cell size. A slight reduction in the thermal conductivity after the additions was ...
The purpose of this study was to produce an environmentally friendly foam using tannins, that did not contain any formaldehyde or blowing agents. Two experimental tannin foams were compared to two conventional foams, one containing both formaldehyde and blowing agents, and the other containing only a blowing agent. A variety of physical properties were assessed to determine if the new green formulation would be an appropriate replacement, this included thermal ...
Rigid foams were prepared using quebracho tannins and their physical and thermal properties were determined experimentally. These properties were then compared to those of rigid foams derived from mimosa tannins and pine tannins to determine if the nature of the flavonoid affects the properties of the foams. It was found that the preparation of the quebracho tannin-based foams involved the same formulation as that of mimosa tannin-based foams, whereas the ...
Calcium is partially substituted by bismuth in the Ca3-xBixCoO9+delta (x=0.00, 0.05, 0.10, 0.15, 0.20, and 0.30) system in order to determine how this substitution affects the thermoelectric and magnetic properties of the system. It was determined that the system had a positive thermopower, and thus the main carriers were holes. A maximum thermoelectric figure of merit of 0.091 was achieved with the Ca2.7Bi0.3CoO9+delta sample. The magnetic property test results indicated that ...
The transient plane source technique was used to measure the thermal conductivity of construction materials at room temperatures. The samples were tested under both dry and partially wet conditions. It was found that the thermal conductivity increased significantly with increasing water content....
