Effects of high temperature treatment of carbon nanotube arrays on graphite: increased crystallinity, anchoring and inter-tube bonding
Artikel i vetenskaplig tidskrift, 2020

Thermal treatment of carbon nanotubes (CNTs) can significantly improve their mechanical, electrical and thermal properties due to reduced defects and increased crystallinity. In this work we investigate the effect of annealing at 3000 degrees C of vertically aligned CNT arrays synthesized by chemical vapor deposition (CVD) on graphite. Raman measurements show a drastically reduced amount of defects and, together with transmission electron microscope (TEM) diffraction measurements, an increased average crystallite size of around 50%, which corresponds to a 124% increase in Young's modulus. We also find a tendency for CNTs to bond to each other with van der Waals (vdW) forces, which causes individual CNTs to closely align with each other. This bonding causes a densification effect on the entire CNT array, which appears at temperatures >1000 degrees C. The densification onset temperature corresponds to the thermal decomposition of oxygen containing functional groups, which otherwise prevents close enough contact for vdW bonding. Finally, the remaining CVD catalyst on the bottom of the CNT array is evaporated during annealing, enabling direct anchoring of the CNTs to the underlying graphite substrate.

crystallinity

carbon nanotubes

annealing

heat treatment

Författare

Josef Hansson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Andreas Nylander

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Mattias Flygare

Karlstads universitet

Krister Svensson

Karlstads universitet

Lilei Ye

SHT Smart High-Tech

Torbjörn Nilsson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Yifeng Fu

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Johan Liu

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Nanotechnology

0957-4484 (ISSN) 1361-6528 (eISSN)

Vol. 31 45 455708

Ämneskategorier

Oorganisk kemi

Polymerteknologi

Materialkemi

Styrkeområden

Produktion

DOI

10.1088/1361-6528/ab9677

PubMed

32454479

Mer information

Senast uppdaterat

2020-10-08