Carbon nanotubes reinforcing effects

Seidel, G. D. and Lagoudas, D. C. Micromechanical analysis of the effective elastic properties of carbon nanotube reinforced composites. Mech of Mater., 38, 884-907 (2006). 

Tserpes, K. I. and Chanteli, A. Parametric numerical evaluation of the effective elastic properties of carbon nanotube-reinforced polymers. Composite Structures, 99, 366-374 (2013). 

Tan, H., Jiang, L. Y, Huang, Y, Liu, B., and Hwang, K. C. The effect of van der Waals-based interface cohesive law on carbon nanotube-reinforced composite materials. Composites Science and Technology, 67,2941-2946 (2007). 

Yesil S. Effect of carbon nanotube reinforcement on the properties of the recycled poly... 

Narh, K. A. Zhu, L. Numerical simulation of the effect of nanotube orientation on tensile modulus of carbon-nanotube-reinforced polymer composites. Polym. Int. 53, 1461-1466 (2(X)4). 

The addition of nanoparticles to synthetic mbber resulting in enhancement in thermal, stiffness and resistance to fracture is one of the most important phenomena in material science technology. Thermal and mechanical properties of clays mul-tiwalled carbon nanotubes reinforced ethylene vinyl acetate (EVA) prepared through melt blending showed synergistic effect in properties [86]. Malas et al. reported (SBR/BR)/expanded graphite (EG) and black carbon (CB) nanocomposites by melt blending, this study demonstrated that the presence of EG improvement thermo-mechanical properties and the presence of CB are a factor important to... 

A reduction of the required energy could be reached by the incorporation of conductive fillers such as heat conductive ceramics, carbon black and carbon nanotubes [103-105] as these materials allowed a better heat distribution between the heat source and the shape-memory devices. At the same time the incorporation of particles influenced the mechanical properties increased stiffness and recoverable strain levels could be reached by the incorporation of microscale particles [106, 107], while the usage of nanoscale particles enhanced stiffness and recoverable strain levels even more [108, 109]. When nanoscale particles are used to improve the photothermal effect and to enhance the mechanical properties, the molecular structure of the particles has to be considered. An inconsistent behavior in mechanical properties was observed by the reinforcement of polyesterurethanes with carbon nanotubes or carbon black or silicon carbide of similar size [3, 110]. While carbon black reinforced materials showed limited Ri around 25-30%, in carbon-nanotube reinforced polymers shape-recovery stresses increased and R s of almost 100% could be determined [110]. A synergism between the anisotropic carbon nanotubes and the crystallizing polyurethane switching segments was proposed as a possible... 

M. Grujicic, Y.-P. Sun, and K. L. Koudela, The effect of covalent fimctionalization of carbon nanotube reinforcements on the atomic-level mechanical propertiesof poly-vinyl-ester-epoxy. Applied Surface Science, 253, 3009-3021 (2007). 

General discussions of the effect of reinforcing agents on the thermal properties of polymers include glass fiber-reinforced polyethylene terephthalate [28], multiwalled carbon nanotube-reinforced liquid crystalline polymer [29], polysesquioxane [30, 31], polynrethane [31], epoxy resins [32], polyethylene [33], montmorillonite clay-reinforced polypropylene [34], polyethylene [35], polylactic acid [36, 37], calcium carbonate-filled low-density polyethylene [38], and barium sulfate-filled polyethylene [39]. 

Ganguli, S., Bhuyan, M., Allie, L. and Aglan, H. (2005) Effect of multi-walled carbon nanotube reinforcement on the fracture behavior of a tetrafunctional epoxy . Journal of Materials Science, 40, 3593-3595. 

Effective elastic properties for carbon nanotube reinforced composites are obtained through a variety of micromechanics techniques [76]. Using... 

Multi-walled carbon nanotubes (MWCNTs) are coated with SiC because MWCNTs are more useful as reinforcements and more cost effective than... 

Lau, K.T., Hui, D., Effectiveness of using carbon nanotubes as nano-reinforcements for advanced composite structures, Carbon, 40, 2002, 1597-1617. 

Sotowa C, Origi G, Takeuchi M, Nishimura U, Takeuchi K, Jang IJ, Kim YJ, Hayashi T, Kim YA, Endo M, Dresselhaus MS. The reinforcing effect of combined carbon nanotubes and acetylene blacks on the cathode electrode of lithium ion batteries. ChemSuschem 2008 1 911-915. 

It should be pointed out that this method relies on the efficient dispersion of nanotubes in the relevant solvent. The choice of solvent is generally made based on the solubility of the polymer. However, pristine nanotubes usually cannot be well dispersed in most solvents. To get around this problem, Xia et al. (17) compared the dispersion of MWNT-graft-PU, MWNT-OH and raw MWNTs in 0.2% aqueous solution of sodium lauryl sulfate. The results showed that MWNT-graft-PU has a better dispersion stability compared to MWNTs and MWNT-OH. The incorporation of polyurethane-grafted carbon nanotubes had a better reinforcing effect compared to the raw carbon nanotubes. This should be attributed to the improved interfacial interaction between polyurethane matrix and carbon nanotubes. 

Although most efforts have been devoted to the use of carbon nanotubes in glassy polymers, some studies have reported strong reinforcing effects of CNTs in elastomeric matrices such as butyl (23), natural (17,24-27) and styrene-butadiene rubbers (28-31) as well as styrene-butadiene and butadiene rubber blends (32). 

An interesting question arises considering composites with multiwalled carbon nanotubes. In such materials there are two possible ways of stress relief upon mechanical strain On one hand, like in other fiber-reinforced composites, the interfacial interaction may be overcome by the mechanical forces so the polymer peels from the nanotubes. On the other hand, however, the individual walls of the MWNT may slide one inside another like a sword in a sheath (so-called interwaU sliding. Figure 3.85). Both effects may occur to varying extents depending on how strongly the multiwalled tubes are bound to the matrix. 

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