Photo- and thermo-mechanical actuation behaviour in specific polymer-carbon nanotube composites has been observed
in recent years and studied at the macroscale. These systems may prove to be suitable components for a wide range of
applications, from MOEMs and nanotechnology to neuroscience and tissue engineering. Absence of a unified model for
actuation behaviour at a molecular level is hindering development of such smart materials. We observed thermomechanical
actuation of ethylene-vinyl acetate | carbon nanotube composites through in situ near-edge X-ray absorption
fine structure spectroscopy to correlate spectral trends with macroscopic observations. This paper presents spectra of
composites and constituents at room temperature to identify resonances in a building block model, followed by spectra
acquired during thermo-actuation. Effects of strain-induced filler alignment are also addressed. Spectral resonances
associated with C=C and C=O groups underwent synchronised intensity variations during excitation, and were used to
propose a conformational model of actuation based on carbon nanotube torsion. Future actuation studies on other active
polymer nanocomposites will verify the universality of the proposed model.
The possibility of novel nanocomposite materials with dramatically improved properties requires fundamental studies of
interactions. Full elucidation of these concepts will allow the tailoring of such systems for particular applications. Using
near-edge X-ray absorption fine structure spectroscopy, we investigated interactions in electrospun
poly(dimethylsiloxane)-poly(methyl methacrylate)-multiwall carbon nanotube composites. This paper describes these
interactions through a building-block model, addresses their dependence upon filler size, and discusses electrospinning
as an alignment solution. Though alignment of filler and polymeric chains was not observed spectrally, SEM imaging
confirmed uniaxial carbon nanotube alignment in composite fibres. Spectra acquired at different incidence angles
revealed differences in energy and intensity of resonances, suggesting conformational configurations. These differences
were more significant in composites with larger nanofiller. This supported proposed models of CH-π interactions and
hydrogen bonding as adhesion mechanisms.