کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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701142 | 1460818 | 2008 | 6 صفحه PDF | دانلود رایگان |
In this work we present a systematic study of the effects of high temperature treatments on the macroscopic physical and mechanical properties of millimeters thick layers of self-standing vertically aligned multi wall carbon nanotubes (MWCNTs).Annealing treatments were carried out on pristine MWCNT chunks in argon gas, in the temperature range of 1500–2200 °C. The analysis showed a change in most of the physical properties as an effect of the graphitization process.Raman results showed a monotonic increase in the crystallite size as the annealing temperature increases due to the lattice defect removal kinetic. Improvement in thermal stability exhibited by thermo-gravimetric analysis in oxidative environment witness a significant reduction in defectiveness.X-ray diffraction confirmed a higher degree of ordering after the annealing process and indicated no significant re-arrangement of the interlayer spacing between the graphene shells. Loading tests showed, beside a negligible change of maximum load, an increase in elastic modulus proportional to the annealing temperature.
Journal: Diamond and Related Materials - Volume 17, Issues 4–5, April–May 2008, Pages 542–547