Molecular Disorder in Prestrained Nanocomposites: Effects of Processing on Durability of Thermally-Active Ethylene-Vinyl Acetate | PyChol | Multiwall Carbon Nanotubes

2015 ◽  
Vol 1718 ◽  
pp. 21-26
Author(s):  
Allen D. Winter ◽  
Cherno Jaye ◽  
Daniel Fischer ◽  
Maria Omastová ◽  
Eva M. Campo

AbstractIn situ temperature-resolved Near-edge X-ray Absorption Fine Structure (NEXAFS) measurements were performed on thermo-active ethylene-vinyl acetate (EVA) – multiwall carbon nanotube (MWCNT) composites 12 months following synthesis, and compared with spectra acquired shortly after synthesis to examine aging effects on non-covalent interactions. Room temperature spectra revealed no difference between unstrained and strained composites, suggesting relaxation. Further, energy shifts in π* C=C resonances indicated a change in π–π interactions between MWCNT walls and chemical dispersant, supported also by AFM phase imaging. Temperature-resolved NEXAFS analysis showed a lack of interaction between nanotubes and polymeric chains, suggesting the chemical dispersant unlatched from MWCNT walls. The extent of this effect is finally quantified through a comparative study of spectral trends.

APL Materials ◽  
2014 ◽  
Vol 2 (6) ◽  
pp. 066105 ◽  
Author(s):  
A. D. Winter ◽  
C. Jaye ◽  
D. Fischer ◽  
M. Omastová ◽  
E. M. Campo

2010 ◽  
Vol 56 (2) ◽  
pp. 693-699 ◽  
Author(s):  
M.M. Rahman ◽  
Jia-Zhao Wang ◽  
Nurul Hayati Idris ◽  
Zhixin Chen ◽  
Huakun Liu

2018 ◽  
Vol 53 (13) ◽  
pp. 1847-1864 ◽  
Author(s):  
K Bilisik ◽  
E Sapanci

The fracture toughness (mode-I) properties of nanostitched para-aramid/phenolic multiwall carbon nanotube prepreg composites were investigated. The fracture toughness (GIC) of the stitching and nanostitched composites showed 42-fold and 41-fold (beam theory), 18-fold and 21-fold (modified beam theory) increase compared to the control, respectively. The prepreg para-aramid stitching yarn and nanostitched yarn were dominant parameters. The toughness resistance to arrest crack growth in the nanostitched composite was primarily due to nanostitching fiber bridging and pull-out, and was secondarily due to nanotubes and biaxial fiber bridging and pull-out. The failed surfaces of the nanostitched and stitching composites had tensile filament failures in the aramid stitching fibers where filament/matrix/nanotube debonding and axial filament fibrillar splitting were found. The results indicated that stitching yarn and the nanotubes arrested the crack propagation. Therefore, the nanostitched and stitched para-aramid/phenolic composites displayed a better damage resistance performance compared to those of the control or nanotube composites.


2012 ◽  
Vol 710 ◽  
pp. 774-779
Author(s):  
Niraj Nayan ◽  
S.V.S. Narayana Murty ◽  
S.C. Sharma ◽  
K. Sreekumar ◽  
Parameshwar Prasad Sinha

Silver reinforced with carbon nanotubes, instead of graphite, would increase both the electrical conductivity, hardness and wear resistance of the electrical brush materials. The effective utilization of carbon nanotubes in the Ag/CNT composite depends strongly on its uniform distribution and strong interfacial adhesion to the silver matrix and thus demands for its surface modification. In order to carry out the surface modification of carbon nanotubes, electroless coating was given to them after liquid phase oxidation, sensitization and activation process. The room-temperature chemical treatment results in a nominally complete coating over the entire outer surface of multiwall carbon nanotube. The surface morphology of the carbon nanotubes after each step has been studied using TGA, DSC, XRD, FTIR and SEM.


2011 ◽  
Vol 364 ◽  
pp. 50-54 ◽  
Author(s):  
Afarin Bahrami ◽  
Z.A. Talib ◽  
W. Mahmood Mat Yunus ◽  
Kasra Behzad ◽  
Nayereh Soltani

This study describes the preparation of polypyrrole multiwall carbon nanotube (PPy/MWNT) composites by in situ chemical oxidative polymerization. Various ratios of functionalized MWNTs are dispersed in the water, and PPy are then synthesized via in-situ chemical oxidative polymerization on the surface of the carbon nanotubes. The morphology of the resulting complex nanotubes (MWNT-PPY) was characterized by field-emission scanning electron microscopy (FESEM). The conductivity of each composite showed a maximum in the temperature scale of 120 – 160 °C and then decreased dramatically with the increase of temperature. The resultant PPy/MWNT nanotubes enhanced electrical conductivity and thermal stability of nanocomposite compared to PPy which was strongly influenced by the feed ratio of pyrrole to MWNTs.


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