Abstract
Abstract
Many surface processes of clay minerals require in-depth understanding of their surface electrical properties, such as surface charge density, surface potential distribution, etc In this paper, electrostatic force microscopy (EFM) and Kelvin probe force microscopy (KPFM) were used to study the surface charge densities, surface potentials, electric field intensities, and electric field force gradients of three common clay minerals: kaolinite, montmorillonite, and illite. The properties were directly imaged, and the average surface permanent charge densities of kaolinite, montmorillonite, and illite were obtained to be −0.0060, −2.136, and −5.456 μC m−2, respectively. In addition, a good linear relationship was found between the surface charge densities obtained by KPFM and the layer charges calculated from the mineral chemical formulas of three clay minerals.
Funder
Guizhou Provincial Basic Research Program
National Natural Science Foundation of China
Strategic Priority Program of the Chinese Academy of Sciences
Frontier Program of State Key Laboratory of Ore Deposit Geochemistry
Subject
Metals and Alloys,Polymers and Plastics,Surfaces, Coatings and Films,Biomaterials,Electronic, Optical and Magnetic Materials