Interface SWNT-polymer

An alternative approach has been shown by Mu and Winey (131), who observed that, while the molecular weight of the polymer matrix has no significant effect on the degree of SWNT dispersion or alignment in the composite, it plays an important role in the load transfer at the SWNT-polymer interface. Therefore, even without functional groups attached to the nanotube, when the polymer chain size is large compared to the nanotube diameter the elastic modulus of the composite greatly increases. 

The development of transparent conductive electrodes based on SWNT thin films represented an outstanding scientific breakthrough for applications in the area of optoelectronics. However, to build integrated CNT-polymer-based systems it is necessary to engineer the interfaces between the two constituents through organized nanotube architectures. 

Unlike the forgoing guest polymers, i.e., SWNT, PANI, PT, and PPE, all of which are soluble or dispersible either into water or into polar organic solvents, PMDS is soluble only in nonpolar organic solvents such as hexane. Accordingly, to prepare highly ordered PMDS/SPG composites with excellent reproducibility, establishment of a novel solubiUzation strategy is desired. A new biphasic procedure, on the basis of the renaturation process of s-SPG on the liquid/liquid interface, is thus exploited. 

The Raman shift of the D band of SWNTs during tensile test suggests a degree of load transfer between PAni matrix and SWNTs which results from a strong nanotube-polymer interface. 

Figure 7.5. Molecular dynamic simulations of PE molecules at the interface of CNT. (a) snapshots of the final conformation of PE with different chain lengths on SWNT (b). [Adapted, by permission, from Ning, N Fu, S Zhang, W Chen, F Wang, K Deng, H Zhang, Q Fu, Q, Prog. Polym. Sci., 37, 1425-55, 2012.]...

Another parameter influencing the mechanical properties of nanotube composites is the CNT alignment. The effects of CNT alignment on electrical conductivity and mechanical properties of CNT-polymer nanocomposites have been discussed in a number of researches [118-120]. For example, it has been reported that with increasing CNT alignment, the electrical and mechanical properties of the SWNT-epoxy composites increased due to an increased interface bonding of CNTs in the polymer matrix [119],... 

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