Six PMMA/SWNT(0.5 wt%) nanocomposite samples intended to have different dispersion levels were prepared by the coagulation method using six different concentrations of SWNTs in DMF from 0.05 mg/ml to 1.2 mg/ml. The morphology of the samples was determined by two different methods, one an absorbance measurement by UV-Vis spectroscopy and the other a statistical analysis of images taken by confocal microscopy. Quantitative dispersion levels were obtained through the image analysis to obtain a relative dispersion index and also through ?2 values representing the uniformity of the dispersion of SWNTs in the samples. The relationships between the quantified dispersion levels and physical properties show about two orders of magnitude variation in storage modulus at low frequencies, at least seven orders of magnitude variation in electric conductivity, and about 70 % reduction in peak mass loss rate at the highest dispersion level. The physical properties correlate better with absorbance than with relative distribution index or ?2 value.
Pub Type: Journals