The molecular structure of kaolinite-potassium acetate intercalation complexes: A combined experimental and molecular dynamic simulation study

The kaolinite (Kaol) intercalated with potassium acetate (Ac) was prepared and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry. Molecular dynamic simulation was performed to investigate the structure of Kaol Ac intercalation complex and the hydrogen bonds between Kaol and intercalated Ac and water using INTERFACE forcefield. The acetate anions and water arranged in a bilayer structure in the interlayer space of Maol. The potassium cations distributed in the interlayer space and strongly coordinated with acetate anions as well as water rather than keyed into the ditrigonal holes of tetrahedral surface of Kaol. Strong hydrogen bonds formed between the hydrogen atoms of hydroxyl on the octahedral surface and oxygen atoms of both acetate anions and water. The acetate anions and water also weakly bonded hydrogen to the silica tetrahedral surface through their hydrogen atoms with the oxygen atoms of silica tetrahedral surface. (C) 2015 Elsevier B.V. All rights reserved.