Stabilization effect of surfactant and functional group on highly concentrated carbon nanotube conductive ink

This study focuses on the analysis of conductivity of resulting carbon nanotube film and UV-vis spectra of carbon nanotube solution to investigate the dispersion and stability of carbon nanotube solution as well as the factors affecting it. The dispersion stability of hydrophilic functional group (-COOH) and surfactant (SDBS) were tested, and was found to behave differently. Hydrophilic functional group tends to increase dispersion stability with increasing concentration, however surfactants shows some optimum points at 0.5wt%. The combination of both stabilization groups has shown a significant improvement in carbon nanotube dispersion quality as well as its stability that is reflected through the observed improvement in the deposited thin film conductivity. Possible mechanism could be explained by ionic repulsive force of functional group ions (-COŌ) and surfactants ions (SO₄̄).