MWCNT-based nanocomposites

The surface-enhanced Raman scattering (SERS)-active substrates were prepared by electrodeposition of Ag nanoparticles in multiwalled carbon nanotubes (MWCNTs)-based nanocomposites for SERS sensor application. 

The novel SERS-active substrates were prepared by electrodeposition of Ag nanoparticles in the MWCNTs-based nanocomposites. The formation of Ag-MWCNTs nanocomposite was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The application of the Ag-MWCNTs nanocomposite in SERS was investigated by using rhodamine 6G (R6G). The present methodology demonstrates that the Ag-MWCNTs nanocomposite is suitable for SERS sensor. 

As shown in Table 5.1, the percolation thresholds in both SWCNT-and MWCNT-based nanocomposites of iPP-g-MA and PS roughly... 

Although the influence of the aspect ratio of the CNTs on the electrical percolation threshold indisputably is felt, we only see relatively small differences in the percolation thresholds for SWCNT-and MWCNT-based nanocomposites. The earlier mentioned viscosity effect and the favorable combination of surface tensions in the case of iPP and the CNTs play a role as well. But the overruling reason for the low percolation threshold of the PP-based composites is without doubt the intrinsic conductivity of the iPP that was used in this study, allowing a relatively large distance between neighboring CNTs and still enabling the electrons to travel through the matrix from one tube to another effortlessly. 

Asmatulu, R., Mahmud, G.A., Hille, C., Misak, H.E. Effects of UV degradation on surface hydrophobicity, crack, and thickness of MWCNT-based nanocomposite coatings. Prog. Org. Coat 72, 553-561 (2011)... 

The effects of carbon-based nanofillers of EG, MWCNTs, and CNFs on the AC conductivity and dielectric constant of elastomeric grade EVA (50% vinyl acetate content) at a particular frequency of 12 Hz, are shown in Fig. 29a, b [194]. EVA-EG, EVA-T, and EVA-F represent EVA-based nanocomposites reinforced with EG, MWCNT, and CNF respectively. 

J. Kim, H. bn, and M.H. Cho, Tribological performance of fluorinated polyimide-based nanocomposite coatings reinforced with PMMA-grafted-MWCNT, Wear, 271 (7-8), 1029-1038, 2011. 

All compounds were melt-blended in a Brabender mixing chamber. It is evident from the results in Table 7.4 that all the filled polymers had improved flame retardant properties. For EVA and EVA-based nanocomposites containing 2.5 phr of filler, the PHRR decreased as follows EVA > organoclays purified MWCNTs. For EVA and EVA-based composites containing 5.0 phr of filler, the PHRR decreased as follows EVA > organoclays > purified MWCNTs = crude MWCNTs. Crude MWCNTs were as effective in the rednction of PHRR as purified MWCNTs Increasing the filler content from 2.5 phr to 5.0 phr caused an additional flame retardant effect that was most significant when purified or crude MWCNTs were used. 

Two insulated wires with identical geometric parameters were produced on a 20-L/D single-screw cable extruder with a 80-mm screw diameter. The diameter of the copper wire was 1.78 nun, and the wall thickness for the insulation was 0.8 mm. For one wire the insulation was compound 1 (filler combination by ATH-organoclay) and for the other wire the optimized compound 2A (filler combination by ATH-organoclay-MWCNTs) was used as insulation. The MWCNT-based compound 2A showed a remarkably increased viscosity over that of the standard nanocomposite compound 1, as indicated by reduced revolutions per minute of the screw and increased power takeup by the extruder motor a high-pressure capillary viscosimeter showed a higher viscosity for compound 2A for all shear rates up to 3000 s ... 

To prepare the MWCNTs/Phenolic-novolac (an epoxy-based vinyl ester (VE) nano eomposites) 6.75 g of VE and 0.162 g of initiator (tert-butyl peibenzoate, TBPB) were dissolved in 2.25 g of styrene monomer and 0.1 g of pristine MWCNTs or the eorresponding amount of MWCNTs/MA-POA400 or MWCNTs/MA-POA2000 was added and the mixture was subjected to sonication for 10 min. The prepared MWCNTA mixture (pristine MWCNTs, MWCNTs/MA-POA400 or M WCNTs/MA-POA2000) was slowly poured onto an aluminum plate and then was cured by slowly increasing the temperature from 80 to 120°C. Finally, MWCNT/ VE nanocomposites were completely eured under vacuum at 140°C for 24 h. 

The aim of this study was the preparation and preliminary investigation of a polymeric based nanocomposite scaffold modified with multi-walled carbon nanotubes (MWCNT) as materials for bone tissue regeneration. For preparation of the nanocomposite scaffold two types of methods were used, i.e. salt leaching and a combination of salt leaching and gas foaming... 

The mechanical properties of nanocomposites containing 0.5%wt., l%wt. and 2%wt. of MWCNT after appropriate dispersion are considerably higher in comparison with pure polymer samples. The results of the mechanical tests for PLDL- based nanocomposite samples are summarized in Table 1. 

Accelerated UV weathering of CNT-epoxy nanocomposites was investigated and most reports did concur in their assessment that it is unlikely for CNTs to be readily released into the environment given their aggregation in high density networks [249, 252, 254—257]. Moreover, an addition of 0.72 or 0.75 wt% [249, 252] of MWCNTs to an amine-cured epoxy-based nanocomposite yielded in an UV radiation resistant material with a surface containing a dense network of nanoparticles that remained unaffected for long terms, without MWCNTs release. 

Hot-melt extrusion has also been used to fabricate nanocomposites. Liao et al. (2013) employed a hot-melt extrusion fabrication technique to fabricate polypropylene-based nanocomposites. Polypropylene, MWCNTs, and HA nanorods were added to the twin-screw extruder. The nanocomposites were molded into rectangular shapes. The authors have hypothesized the potential of the fabricated nanocomposite for bone implants. 

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