A novel polyimide (PI)/clay hybrid nanocomposite, designated as PI (PAAS)/CM, has been developed from the poly(amic acid) salt of triethylamine and organomontmorillonite (CM) using a mixture solution of tetrahydrofuran (THF) and methanol (MeOH). For comparison, two other PI/clay hybrids derived from poly(amic acid) and CM in THF/MeOH solution and N,N9-dimethylacetamide (DMAc) solution, denoted ...

We report experimental data of creep cavity shrinkage for dispersion-strengthened-cast aluminum with about 23 vol pct submicron Al2O3 dispersoids, annealed isothermally or subjected to thermal cycling without applied stress. Thermal cycling is found to increase the rate of densification by a factor of 3 to 5.5 relative to isothermal annealing at the upper cycling temperature, allowing for recov...

A new thermally conductive polyimide composite film has been developed. It is based on a dispersion of different particle sizes of boron nitride (BN) in a polyimide (PI) precursor, polyamic acid (PAA). Subsequently, thermal imidization of PAA at 350 degrees C produced the corresponding polyimide composites. 3-Mercaptopropionic acid was used as the surfactant to modify the BN surface for the dis...

Polymer nanocomposites have attracted great interest over many years, because of the enhanced properties exhibited by such systems. However, it is only recently that the electrical characteristics of this class of material have begun to be studied in detail. Whenever fillers are added to a host polymer matrix, dispersion is of critical importance since, while a well dispersed nanophase may be b...

We have simulated the heat conduction characteristics of finite length single walled carbon nanotubes (SWNTs) with the molecular dynamics method [1-3] with Tersoff-Brenner bond order potential. Temperature at each end of a SWNT was controlled by the phantom technique, and the thermal conductivity was calculated with Fourier’s law from the measured temperature gradient and the energy budgets in ...

In this paper, we design the zero-dispersion wavelength shifted fiber based on the WII-type triple clad single mode optical fiber and consider the transmission parameters fluctuations owing to environmental conditions such as temperature variations on dispersion behavior of fiber. In order to estimate the thermal coefficients, the model introduced by Ghosh [1] is applied. Our calculation show t...

Nanofluids with enhanced thermal properties are candidates for thermal management in automotive systems, with scope for improving energy efficiency. In particular, many studies have reported on dispersions of nanoparticles with long-term stability in the base fluid, with qualitative evaluations of the dispersion stability via either the naked eye or optical instruments. Additives such as surfac...

The present investigation was carried out to evaluate the application of Cloisite 30B organoclay (C30B) on the rheological, structural, electrical, and thermal characteristics of poly (methyl methacrylate)/multiwalled carbon nanotubes nanocomposites (PMMA/MWCNTs) fabricated by the simultaneous melt mixing. The microstructure and the state of nanofllers dispersion wereassessed by melt line...

Magnesium has been used in aviation industries, automobile manufacturing, electronics and medical engineering due to its unique properties thus far. The main problem in its utilization is the high reactivity of magnesium with oxygen and humidity, which both changes its properties. The surface charge and different density results in difficulties in dispersion stability of the powder in an ...