Effective reinforcement in carbon nanotube–polymer composites

Abstract

Carbon nanotubes have mechanical properties that are far in excess of conventional fibrous materials used in engineering polymer composites. Effective reinforcement of polymers using carbon nanotubes is difficult due to poor dispersion and alignment of the nanotubes along the same axis as the applied force during composite loading. This paper reviews the mechanical properties of carbon nanotubes and their polymer composites to highlight how many previously prepared composites do not effectively use the excellent mechanical behaviour of the reinforcement. Nanomechanical tests using atomic force microscopy are carried out on simple uniaxially aligned carbon nanotube-reinforced polyvinyl alcohol (PVA) fibres prepared using electrospinning processes. Dispersion of the carbon nanotubes within the polymer is achieved using a surfactant. Young's modulus of these simple composites is shown to approach theoretically predicted values, indicating that the carbon nanotubes are effective reinforcements. However, the use of dispersant is also shown to lower Young's modulus of the electrospun PVA fibres.

A review on the role of interface in mechanical, thermal, and electrical properties of polymer composites

“…Figure 8 shows the pull out technique which was used by Barber et al for the first time. Using this method, they could measure the critical force required for interfacial failure between CNT and a copolymer melt [113]. In the pull out method, the CNT attached tip will approach the polymer melt, while the applied force on the cantilever is simultaneously recorded as a function of time.…”

“…9 Force vs. time plot for the pull out approach: a the nanotube is already in the polymer bath; b by pulling out the nanotube, the cantilever will be deflected until it reaches its maximum deflection at c. At d, the pull out is occurring, while at e, it is completely out of the bath [111] Fig. 8 CNT attached AFM tip is immersed in the resin followed by pulling out and measuring its required force simultaneously [113] Advanced…”

The effect of carbon nanotube aspect ratio and loading on the elastic modulus of electrospun poly(vinyl alcohol)-carbon nanotube hybrid fibers

“…Of interest was the comparison of the LSA dispersion method with other surfactant-based dispersion methods [38] such as sodium dodecyl sulfate for PVA-CNT hybrid fibers. Our procedure was able to fabricate hybrid fibers with consistently high CNT loading as indicated by Raman spectra (Fig.…”

Nanotubes Reinforcement of Degradable Polymers for Orthopedic Applications

“…To fully exploit the properties of CNTs as fillers in polymer matrices, their chemical modification is necessary. A simple way to disperse the CNTs in the polymer solution is the use of surfactants, like sodium dodecyl sulphate 76 or the addition of carboxyl, hydroxyl, amino or alcohol groups. Another way to increase the reinforcement of polymers is the use of mechanically interlocked derivatives of single walled carbon nanotubes (SWNTs).…”