Effect of nonionic surfactant on stability of graphite-H₂O dispersion

The nonionic surfactant (TX-100) was chosen as dispersant, and graphite-H2O dispersion with high stability was prepared. The potential factors related to the stability of the dispersion such as TX-100 content, pH value, and electrolyte were studied by the method of Zeta potential and absorbency, and the mechanism of action was also analyzed, respectively. The results showed that the good stability of dispersion was achieved under the condition of adding 25% (w) of TX-100 based on the weight of graphite. It was indicated that pH value had a faint effect on the stability of the dispersion, and the good stability of the dispersion could be obtained in a wide pH value range. Under the condition of pH=3, the charge neutralization and relatively flat conformation on graphite surface of TX-100 made the stability of the dispersion descend. It was also shown that electrolyte could disturb the stability of the dispersion. In this system, electrostatic stabilization can influence the stability of the dispersion, in addition to steric stabilization. The viscosity curve and particles size distribution of graphite-H₂O dispersion showed the graphite particles reach a fine dispersion degree in water.