Microwave Absorption of Single-Walled Carbon Nanotubes/Soluble Cross-Linked Polyurethane Composites

Abstract

Processable composites of single-walled carbon nanotubes (SWNTs) with soluble cross-linked polyurethane (SCPU) were prepared at various loadings of SWNTs (0-25 wt %), and they exhibited strong microwave absorption in the microwave range of 2-18 GHz. For example, 5 wt % loading SWNTs/SCPU composite has a strong absorbing peak at 8.8 GHz and achieves a maximum absorbing value of 22 dB. The absorbing peak position moves to lower frequencies with increasing SWNT loading. Theoretical simulation for the microwave absorption using the transmission line theory agrees well with the experimental results. The microwave absorption of these composites can be mainly attributed to the dielectric loss rather than magnetic loss.

Effect of carbon nanotube dispersion on the complex permittivity and absorption of nanocomposites in 2–18 GHz ranges

“…From the measured complex transmission and reflection scattering parameters (S 11 and S 21 ), the frequency dependence of e 0 , e 00 , l 0 , and l 00 for each sample was then obtained using Agilent 85071E material measurement software which is based on Nicolson-Ross-Weir's reflection/transmission formulation using scattering parameters of the reflected and transmitted transverse electromagnetic (TEM) waves in the frequency range 2-18 GHz. 21 The effects of air gap between the sample and holder were automatically corrected by the built-in algorithm of Agilent 85071E when the actual size of the sample was input into the software. In the present study, the CNT/epoxy composite is a nonmagnetic material and the measurement shows that the features of l 0 is nearly equal to 1 and l 00 is very close to zero despite the consequences of frequency and concentration of CNTs.…”

Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

“…Theoretical calculations show that CNTs act to like insulators, semiconductors or metals depending on their radii and chiralities. Composites with multiwalled carbon nanotubes (MWNTs) embedded into a polymer host have been use to microwave applications, such as antireflection, electromagnetic interference shielding (EMI) or microwave absorber 1,[47][48][49][50][51][52][53][54] . Thus, the objective of this work was to process nanostructured composite materials based on formulations containing different quantities of multiwalled carbon nanotubes in an epoxy resin matrix, aiming to determine the adequate quantity of CNT for processing X-band microwave absorbing nanostructured composite.…”

Adsorption Properties and Potential Applications of Bamboo Charcoal: A Review

“…There are three main strategies on producing the adsorbing material: 1) dispersion of metallic fillers, fibers or nanoparticles within polymer matrix which can increase the interaction with the electromagnetic radiation; 2) using conductive polymers such polyaniline (PANI) and polydimethylsiloxane (PDMS) and 3) dispersion carbon based electrically conductive polymer matrices. Based on that, carbon material like carbon black [20], carbon nanotubes [21] and graphene [22 -24] have been used as the polymeric filler because of their extraordinary properties. However the production of these carbon materials is expensive and some of the materials are facing impedance match mechanism that may harmful to the EM adsorption properties [24].…”