Morphology, thermal expansion, and electrical conductivity of multiwalled carbon nanotube/epoxy composites

Santos, Alexandre Soares dos; Leite, Thiago de O. N.; Furtado, Clascídia Aparecida; Welter, Cezar; Pardini, Luiz Carlos; Silva, Glaura G.

doi:10.1002/app.27614

Cited by 40 publications

(22 citation statements)

References 32 publications

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“…1) an open structure consisting of entangled bundles, with diameters between 50 and 200 nm. The BET specifi c surface area, measured by nitrogen adsorption, is 136 m 2 /g [24]. The MWNT material presents a fraction of residual metal of approximately 6 wt% (calculated as ~70% of the final residue weight, corresponding to either Ni, Co, or Fe metallic oxides), as shown by the thermogravimetric residue of ~ 9 wt% in Fig.…”

Section: Resultsmentioning

confidence: 97%

Polymeric nanomaterials as electrolyte and electrodes in supercapacitors

et al. 2009

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The energy challenge requires a broad range of options for energy harvesting, storage, and conversion. We have produced polymeric coatings by spraying, to be used as electrolyte and electrodes in a fl exible electrochemical double layer capacitor. A thermoplastic polyurethane and a low molecular weight block copolyether were employed with LiClO 4 to prepare solid polymeric electrolytes. Carbon black (CB) and multi-walled carbon nanotubes (MWNTs) were dispersed in the polymer blend electrolyte to produce nanostructured composite electrodes. The conductivities increased with the addition of block copolyether and carbon nanotubes to the electrolyte and electrode, respectively. Scanning electron microscopy (SEM) and atomic force microscope (AFM) images of the nanocomposite electrodes showed nanoagglomerates of CB connected by carbon nanotubes. The solid supercapacitor prepared with these new materials as electrolyte and electrodes showed superior performance to other similar systems. The resulting safe and fl exible multilayer device can meet the requirements of modern devices. KEYWORDSPolymeric electrolyte blend, nanocomposite electrode, carbon black, carbon nanotube, supercapacitor Electrochemical capacitors or supercapacitors [1,2], using the electric double layer charge at the electrode/electrolyte interface of a highly porous electrode, can have an important role in new technologies. The properties of supercapacitors complement the defi ciencies of other power sources, such as batteries and fuel cells [3].Nanostructured carbon-based materials have been used in electrodes for electrochemical double layer capacitors (EDLC). The relationship between the surface area, total pore volume, average pore size, and the pore size distribution of the materials has a strong infl uence on the electrochemical characteristics of the resulting capacitor [3,4]. In such devices, activated carbons, carbon black or carbon nanotube composites have been employed as electrodes [3 6], mainly with liquid electrolytes [7]. Usually, the electrolytes employed in the electrochemical capacitors are acids, bases or salts dissolved in aqueous or organic solvents. Ionic liquids have also been investigated in supercapacitors [8 10]. The use of corrosive liquid electrolytes may cause dangerous leakages, which decrease the safety and lifetime of the capacitors [11,12]. To reduce problems associated Nano Research 734Nano Res (2009) 2: 733 739 with the management of corrosive ionic conductors, as well as to allow the preparation of thin film cells with high reliability, the use of solid polymer electrolytes (SPE) has been proposed [11, 13 16]. The performance of carbon-based polymer supercapacitors is closely associated with the characteristics of the materials used, such as new carbonaceous and electrolytes. The characteristics of the polymer electrolyte need to be tailored with the goal of increasing conductivity under specific experimental conditions. A degree of matching between the carbonaceous pore size and the microstructural arra...

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Section: Resultsmentioning

confidence: 97%

Polymeric nanomaterials as electrolyte and electrodes in supercapacitors

et al. 2009

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“…The processes of covalent and noncovalent functionalization have been suggested as one of the options for better dispersion of nanotubes 27,[41][42][43] . The chemical modification of the nanotube surface through covalent functionalization results in reduction of the aspect ratio with the formation of sp 3 carbons on nanotube surface, which decreases the electrical conductivity of nanotubes 27,[44][45][46][47] . Therefore, as-received nanotubes were used in the present work without any functionalization, once this study is focused on the electromagnetic properties.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2013

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Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multiwalled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations.

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“…Although the CNT production cost is higher than that of conventional fillers, its low loading is advantageous because the effects on resin properties are minimal and the same processing equipment can be used with neat resins and nanocomposites. These polymer-based nanocomposites are expected to derive high properties at low filler volume fractions due to the high aspect ratio and high surface area to volume ratio of the nano-sized particles [Zhou et al, 2008;Hu et al, 2008;Santos et al, 2008]. In recent years, different types of polymer composites have been synthesized by incorporating CNTs into various polymer matrices such as polyamides [Zhao et al, 2005], polyimides [Cai et al, 2004;Ogasawara et al, 2004], epoxy [Winey et al, 2007;Hu et al, 2008;Liao et al, 2004], polyurethane [Koerner et al, 2005 ;Kuan et al, 2005], polypropylene [Seo et al, 2004;Li et al, 2004;Seo et al, 2005], polyethylene [Haggenmueller et al, 2006], polyethylene oxide [San et al, 2001], poly(vinyl alcohol) , poly(methyl methacrylate) [Jin et al, 2001], polycarbonate [Postscke et al, 2003], poly(butylene succinate) [Sinha Ray & Okomoto, 2003], polylactide [Chiu et al, 2008], polyaniline [Zing et al, 2008], polypyrrole [Sahoo et al, 2007], poly (N-vinylcarbazole) [Maity et al, 2007;Maity & Sinha Ray, 2008a ;Maity & Sinha Ray, 2008b], poly(ethylene 2, 6-naphthalate) , poly(butylenes terephthalate) [Garcia-Gutierrez et al, 2008], poly(p-phenylene benzobisoxazole) [Kumar et al, 2002], glycopolymer and others [Fragneaud et al, 2007].…”

Section: Swcnt Graphene Sheetmentioning

confidence: 99%

“…The composite was moulded and cured at 80°C for 2 h, followed by post-cure at 150°C for 3 h. Several different combinations of CNT/GNP hybrid nanoreinforcement contents were added into the epoxy matrix, with the CNT contents ranging 0-1.0 wt% while the total filler content was maintained at 2 wt% loading. Santos et al [Santos et al, 2008] investigated the nanocomposite prepared from CVD-grown MWCNTs (diameter 10-40 nm, length 5-20 μm, surface area 136 m 2 /g), XR1555 epoxy resin and HY-951 Aradur hardener. MWCNTs were suspended in a 1 wt% SDS solution [Connel et al, 2002], and the mixture was ultrasonicated for 90 min.…”

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confidence: 99%