Effect of the Morphology and Structure on the Microwave Absorbing Properties of Multiwalled Carbon Nanotube Filled Epoxy Resin Nanocomposites

Abstract

The current research shows the effect of structural and morphological differences of multilayer carbon nanotubes (CNT) on radar absorbing materials (RAM) performance. Two CNT samples, from different manufacturers, had their morphological and structural aspects investigated by XRD, SEM and SEM-FEG analyses. CNT/epoxy resin based nanostructured composites were prepared and characterized by reflectivity measurements in the X-band. SEM results show the formation of agglomerates in the composites and the XRD patterns show structural differences between the two CNT samples. The best RAM performance (-25 dB) was determined for the nanocomposite based on the CNT with the smallest stacking layers (Lc = 26.9 Å) associated to the longest length of nanofilament (10-20 µm). This characteristic can have contributed to the formation of an interconnected network in the composite favoring electrical conductivity and dielectric properties, with the consequent increase of the wave attenuation.

The influence of carbon nanotube buckypaper/poly (ether imide) mats on the thermal properties of poly (ether imide) and poly (aryl ether ketone)/carbon fiber laminates

“…From the spectra obtained by XRD, there are two peaks, the first peak (002) being approximately at 25 • associated with a graphitic material that refers to the distance between the sheets of concentric graphene that make up the MWCNTs. The second peak (100) is at 43 • and is associated with the turbostratic structure (structure composed of carbon planes that resemble interlaced ribbons, with bidirectional ordering and arrangement in the third direction) [58,59] of carbonaceous materials. From the spectra, it was possible to calculate the crystallites' dimensions that are normally expressed by the average height (L c or L 002 ) and the average length of the layers (d 002 ).…”

Production of an Efficient Magnetic Adsorbent From Babassu Coconut Endocarp and Ni Particles for Easy Dye Removal From Mimetic Contaminated Effluents

“…The diffractogram of the pure BAC sample exhibits broad peaks at ca. 23° and 43°, assigned to the (002) and (200) re ections of the turbostratic structure of the carbon matrix (Carreño et al 2002;Li et al 2007;Silva and Rezende 2018;Zanoteli et al 2014). A small peak ascribed to silicon dioxide (SiO 2 ) is also detected at 22.4°, in accordance with Freitas et al (2000), that assigned this peak around 22° and it is a consequence of the natural occurrence of Si-containing compounds in the endocarp of babassu coconut.…”

Manufacturing radar-absorbing composite materials by using magnetic Co-doped zinc oxide particles synthesized by Sol-Gel

“…The radar wave absorbing properties of composites were substantially improved after the addition of Co-doped ZnO powders; absorbing percentage increases with increasing Co content in the powders. [33][34][35] The absorbing peak reaches 93% at 10.9 GHz with the 12% Co-doped ZnO powder reinforced composite. In Figure 7(b), 9% Co content ZnO powders (Zn 0.91 Co 0.09 O) were used at a different amount in the composite.…”