Aggregation mechanism of colloidal kaolinite in aqueous solutions with electrolyte and surfactants

• Published in: PloS one Vol. 15; no. 9; p. e0238350
• Main Authors: Hu, Yang, Yang, Qingyang, Kou, Jue, Sun, Chunbao, Li, Hongliang, Zheng, Jie
• Format: Journal Article
• Language: English
• Published: San Francisco Public Library of Science 21.09.2020; Public Library of Science (PLoS)
• Subjects: Adsorption; Agglomeration; Aqueous solutions; Chemical properties; Chemical research; Compression; Contact angle; Earth Sciences; Electric double layer; Electrolytes; Electrostatic properties; Engineering; Flocculation; Hydration; Hydrophobicity; Kaolinite; Methods; Mineral processing; Physical Sciences; Pollutants; Polymers; Sedimentation & deposition; Sodium chloride; Stability analysis; Surface active agents; Surfactants; Zeta potential; China; Beijing China; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0238350

In this study, the effect of surfactants and electrolytes on stability of kaolinite dispersions was analyzed by measuring suspension transmittance, zeta potential, and adsorption. It was experimentally found that the compression of kaolinite electric double layer caused by NaCl addition may reduce the electrostatic repulse force to facilitate the aggregation of kaolinite particles. Surfactant facilitate the aggregation of kaolinite particles mainly through the adsorption of it on the surface of kaolinite to generate hydrophobic force. Compared to anionic surfactant, the cationic surfactant has a better flocculation effect because it can be used in a wide pH range and its adsorption can reduce the electrostatic repulse force between kaolinite particles.