A collection of AlSi7 foams (porosities 0.5 to 0.8) were analyzed using the TPS technique in order to determine thermal conductivity. Increased density was found to lead to increased thermal conductivity. The TPS technique was found to be sensitive to the in-homogeneities created from the foaming process; therefore the foaming process is an important factor in the determination of thermal conductivity of a given foam. The authors also combined several theoretical models ...
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 ...
Through the addition of graphite powder (GP) and expanded graphite (EG) the authors were able to increase the thermal conductivity of a shape-stabilized paraffin/high density polyethylene (HDPE) composite phase change material (PCM). GP and EG were added in different mass fractions and a Thermal Constants Analyzer was used in order to measure the thermal conductivity. The relationship between mass fractions of GP and EG added were found to have ...
As electronic devices become smaller, power densities increase and so do hotspot temperatures, leading to a need for materials that can exchange heat better. The materials that facilitate this heat exchange are called thermal interface materials (TIMs). Graphene has been shown to demonstrate superior thermal conductivity and a particular form called few-layer graphene (FLG) was used in this project. A novel TIM was created by the mixing of a silver ...
A variety of nano and micro-sized boron nitride (BN) particles were dispersed in a polyimide (PI) precursor polyamic acid (PAA) using a surfactant in order to generate a thermally conductive polyimide composite film with excellent thermal properties. The observed thermal conductivities varied with the BN weight % and the particle size. BN weight % was raised as high as 30%, which resulted in a thermal conductivity of 1.2 W/mK. Glass transition and thermal ...
