Improving the Dispersion and Integration of Multi-Walled Carbon Nanotubes in PolyvinyI-Alcohol Composite Thin Film through Surface Modification

The article investigated the influence of modification process parameters on dispersity of MWNTs DI （in deionized） water and PVA/MWNT composite＇s electrical conductivity. Experimental results obtained by SEM （scanning electron microscope）, TEM （transmission electron microscope）, transform Fourier infrared spectroscopy, pH meter confirmed the most effective conditions in modifying the MWNT surface at the 1：3 mixture of nitric and sulfuric acid at 60 ℃. The extinction coefficient value of functionalized MWNTs at 500 nm wavelength was determined to be 41.24 cm^2·mg^-1, while their dispersibility in DI water was about 12.85 mg/mL and stable in more than 3 weeks via UV-vis spectroscopy. The other important result is the decrease of volume resistivity from 7.98 × 10^6 MΩ·m ofPVA （polyvinyl alcohol） to 4.15 × 10^4 MΩ·m of PVA/1 wt% modified MWNT thin film.