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Cobalt Catalyst Grown Carbon Nanotube/Poly(Vinylidene Fluoride) Nanocomposites: Effect of Synthesis Temperature on Morphology, Electrical Conductivity and Electromagnetic Interference Shielding
Author(s) -
Keteklahijani Yalda Zamani,
Arjmand Mohammad,
Sundararaj Uttandaraman
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201701929
Subject(s) - materials science , carbon nanotube , nanocomposite , crystallinity , polyvinylidene fluoride , percolation threshold , thermogravimetric analysis , composite material , cobalt , dispersion (optics) , chemical engineering , polymer , electrical resistivity and conductivity , engineering , electrical engineering , metallurgy , physics , optics
A chemical vapor deposition technique was executed to synthesize multi‐walled carbon nanotubes (CNTs) at different temperatures (550, 650, 750 and 850 °C) using cobalt catalyst. Different concentrations of the synthesized CNTs were melt mixed with a polyvinylidene fluoride (PVDF) matrix, and then compression molded. The nanocomposites containing CNT 650 had significantly lower electrical percolation threshold (0.3 wt.%) and higher electromagnetic interference shielding effectiveness compared to their counterparts. We investigated the underlying reasons by means of various characterization techniques, where the most significant results are as follows. Thermogravimetric analysis demonstrated that the synthesis temperature of 650 °C leads to superior carbon purity and CNT quality. We found that 650 °C is the optimum temperature providing sufficient energy for the synthesis with minimum catalyst sintering. Employing light microscopy and transmission electron microscopy, it was realized that CNT 650 had better micro‐dispersion and nano‐dispersion states within the polymer matrix than the other CNTs. Different characterization methods established that the superior electrical properties of nanocomposites containing CNT 650 are attributable to a combination of high carbon purity, high aspect ratio, and high crystallinity of CNT 650 along with optimum dispersion state of CNT 650 within the PVDF matrix.