DFT study of the intercalation of layered double hydroxides and layered hydroxide salts with dodecylsulfate and dodecylbenzene sulfonate: Exfoliation and hydration properties

Publication date: July 2017
Source:Applied Clay Science, Volume 143
Author(s): Sérgio R. Tavares, Fernando Wypych, Alexandre A. Leitão
DFT calculations were performed for the simulation of the intercalations of Zn2Al-layered double hydroxide and Zn-layered hydroxide salts with dodecylsulfate and dodecylbenzene sulfonate. A structural and energetic analyses of the exfoliation processes were computed and compared with Perdew-Burke-Ernzerhof exchange-correlation (PBE) and Van der Waals-aware density (vdW-DF) functionals and with the semi-empirical approach DFT-D2. It could be concluded that the layers cell parameters were not affected by the applied approach. On the other hand, the basal spacing and the exfoliation energies presented variations with respect to the simulation. The influence of water molecules hydrating the polar heads of the anions intercalated in the interlayer region was also investigated. Furthermore, the interactions between the anions and the positive layers and the influence of hydration waters could be resolved by means of charge density difference plots and Bader charges. Projected density of states (PDOS) showed the possible acid and basic sites of these compounds for both dehydrated and hydrated structures.

Graphical abstract

http://ift.tt/2nJ0Ftw