The surface properties of layered silicate minerals are important in geology, geo-technology, mineral processing, agriculture and the production of engineered materials. These layered silicates in a pure state are of significant value and can be a blessing while in other cases they may be a curse. And layered silicateshave puzzled researchers for a very long timeregarding surface properties.

Researchers with Institute of Process Engineering (IPE) and other foreign researchers made a review on the surface chemistry characteristics of the layered silicates such as mica, talc, and kaolinite, which included recent surface charge results based on atomic force microscopy (AFM) surface force measurements and the wetting characteristics studied using experimental techniques and the molecular dynamics simulation (MDS) method.

The surface charge properties were defined based on face and edge surfaces.Yan et al. successfully prepared molecularly smooth edge surfaces of layered silicates with natural cleavage planes by an ultramicrotome cutting technique. So the charging behavior of the edge surfaces for muscovite and talc were determined by surface force measurements using AFM.Besides, the paper also presented the surface potentials of the kaolinite silica face and the alumina face.

Wetting, another important surface property, was defined as the ability of a liquid to maintain contact with a surface. A variety of techniques were used to study of the wettability of layered silicates.Contact angle measurement was one of the most prevailing methods todetermine the hydrophobicity of layered silicates.

The wettability of trilayer silicates and bilayer silicates were examined with AFM surface forcemeasurement and molecular dynamics simulations. In addition, the hydrophobic state of certain silica tetrahedral surfaces (face surfaces) was evident based on the analysis of interfacial water structure.

The paper was published in Advances in Colloid and Interface Science.