Microwave conductance of aligned multiwall carbon nanotube textile sheets

Abstract

Multiwall carbon nanotube (MWNT) sheets are a class of nanomaterial-based multifunctional textile with potentially useful microwave properties. To understand better the microwave electrodynamics, complex AC conductance measurements from 0.01 to 50 GHz were made on sheets of highly aligned MWNTs with the alignment texture both parallel and perpendicular to the microwave electric field polarization. In both orientations, the AC conductance is modeled to first order by a parallel frequency-independent conductance and capacitance with no inductive contribution. This is consistent with low-frequency diffusive Drude AC conduction up to 50 GHz, in contrast to the “universal disorder” AC conduction reported in many types of single-wall nanotube materials.

Carbon Nanotubes as an Alternative to Copper Wires in Electrical Machines: A Review

“…The temperature coefficient of the copper at room temperature is 3.886 × 10 −3 K. The density of silver is high compared to copper. Still, it has nearly the same temperature coefficient as silver at 3.8 × 10 −3 K. Aluminium has a higher resistivity than copper and silver, and the temperature coefficient of aluminium is 3.9 × 10 −3 K. The temperature coefficient of CNTs is negative at a temperature of −0.2 × 10 −3 K. This temperature coefficient reduces the resistivity of the CNT fibres, which improves the electrical characteristics of the CNT in terms of electrical conductivity [78]. The temperature coefficient of CNT-Cu at room temperature is 1.7 × 10 −3 K. The temperature coefficient of CNT-Al is 1.7 × 10 −3 K.…”