PDF Publication Title:
Text from PDF Page: 047
eliminated the failure prone skin-core structure that was identified in literature as a structural weakness of this class of nanofibers. The tensile strength increased monotonically reaching its maximum at 1400°C, while the elastic modulus increased steadily until 1700°C. The formation of turbostratic carbon crystallites with 3 - 8 layers thickness was among the reasons for increased modulus but also the source of failure initiation at high carbonization temperatures. The random orientation of the crystallites pointed to the necessity for stronger molecular alignment in the PAN precursor, to improve both the strength and the modulus. As the characteristic strength increased from 2.2 GPa to 3.6 GPa for fibers produced at 800°C and 1400°C, the Weibull modulus also increased from 3 to 6, which indicates that the higher processing temperature removed the major defects in the nanofibers. Carbonization at the higher temperature of 1700°C reduced the Weibull modulus to about 3 due to the formation of large and randomly distributed turbostratic carbon crystallites which acted as stress concentrations and sites for failure initiation. Finally, it should be noted that the versatile MEMS-based experimental tools made nanoscale tension experiments possible at the single nanofiber level, which proved instrumental in establishing the processing-structure-property relationships presented in this dissertation. 40PDF Image | HIGH STRENGTH CARBON NANOFIBERS DERIVED FROM ELECTROSPUN POLYACRYLONITRILE
PDF Search Title:
HIGH STRENGTH CARBON NANOFIBERS DERIVED FROM ELECTROSPUN POLYACRYLONITRILEOriginal File Name Searched:
4835609.pdfDIY PDF Search: Google It | Yahoo | Bing
Sulfur Deposition on Carbon Nanofibers using Supercritical CO2 Sulfur Deposition on Carbon Nanofibers using Supercritical CO2. Gamma sulfur also known as mother of pearl sulfur and nacreous sulfur... More Info
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |