Search Results for: carbon nanotubes

Total Search Results Found: 72

Preparation and characterization of thermally conductive polystyrene/carbon nanotubes composites

Researchers in this study aimed to develop polymer composites with high thermal conductivity, using polystyrene (PS) and multi-walled carbon nanotubes (MWNTs). These composites were prepared by ultrasonic radiation, through a simple-solution-evaporation method. Poly(styrene-co-maleic anhydride) (PSMA), with a benzene group and experiencing a strong affinity for PS was used as a base, to allow the MWNTs to be dispersed within the composite (MWNT-g-SMA). Results determined that the addition of MWNTs to the PS increased thermal conductivity, but mechanical properties faltered. However, with the addition of MWNT-g-SMA (33.3 vol %), the mechanical properties were improved to an extent, all the while maintaining a higher thermal conductivity (0.89 W/mK). Also, a linear trend of thermal conductivity with increasing MWNT-g-SMA content, was noted.

Flame retardancy through carbon nanomaterials: carbon black, multiwall nanotubes, expanded graphite, multi-layer graphene and graphene in polypropylene

This research aims to determine the effect of altering filler particle sizes and shapes, on the thermal and mechanical properties of polypropylene (PP). Fillers such as thermally reduced graphite oxide (TRGO), multi-layer graphene (MLG250), carbon black (CB), multiwalled nanotubes (MWNT) and expanded graphite (EG), were added to the PP base. A thermal analyzer was used to measure the thermal conductivity of the various PP composites. Results determined that the PP bases containing CB, MLG250 and TRGO, had drastically altered fire behaviour, with their temperature of decomposition pushed 30°C higher than it was previously. The thermal conductivity of all the PP composites were enhanced with the addition of fillers, with exception to the addition of CB. The filler to enhance the thermal conductivity of PP the most was MLG250, by a factor of 1.4.

Structure and properties of highly oriented polyoxymethylene/multi-walled carbon nanotube composites produced by hot stretching

Using a solid hot stretching technique, highly-oriented polyoxymethyelen (POM)/multi-walled carbon nanotubes (MWCNTs) composites were created. Thermal properties were analyzed both in the stretched and through-plane directions. Researchers found that by increasing the draw ratio, to as high as 900%, the thermal conductivity of the composite has improved in the stretching direction, when compared to the material prior to this process. Researchers also determined that the thermal conductivity of the MWCNTs composite can reach as high as 1.2 W/mK, after the stretching process.

Surfactant-free ionic liquid-based nanofluids with remarkable thermal conductivity enhancement at very low loading of graphene

The Transient Plane Source method was used in this research article to measure the thermal conductivity of an Ionanofluid, highly stable graphene (GE)-based nanofluid, at various temperatures. Researchers took special note of the effects of temperature, GE loading, presence of multi-walled carbon nanotubes (MWCNTs), on the thermal conductivity of the nanofluid. Through experimental testing, it was determined that the nanofluid elicited a higher thermal conductivity, as compared to its base fluid. Thermal conductivity was also noted to increase as temperature and GE-loading increased. On the contrary, thermal conductivity of the nanofluid was seen to decrease as the load of MWCNTs increased. This finding correlates with the higher thermal conductivity of graphene, as compared to the MWCNTs.

Effects of MWNTs on phase change enthalpy and thermal conductivity of a solid-liquid organic PCM

In this paper, researchers investigated the effects of multi-walled carbon nanotubes (MWNTs), on the thermal conductivity and phase change enthalpy of palmitic acid (PA), a solid to liquid phase change material. The research concluded that as the concentration of MWNTs is increased, the thermal conductivity of the composite increases, compared to that of PA alone. Also in this study, researchers investigated the effects of various MWNTs surface modifications, on the thermal conductivity and phase change enthalpy of the composite.