HLAVÁČ Dominik VSB - Technical University of Ostrava

Non-bond Interactions between Chlorhexidine Diacetate and Kaolinite: a Molecular Modeling Study

Co-authors TOKARSKÝ Jonáš

Chlorhexidine/kaolinite nanocomposite is a phyllosilicate-based material exhibiting antibacterial properties. For further optimization of preparation process and improvement of resulting nanocomposite the structure at an atomistic level should be known more precisely. Present work is focused on utilization of molecular modeling during this task. Complex systems containing kaolinite matrix (tetrahedral surface, octahedral surface, and edge of kaolinite are taken into account) and chlorhexidine diacetate, urea and water molecules were investigated using empirical force field developed by Rappe and co-workers. Forcite module in Accelrys Materials Studio modeling environment was used in order to obtain series of structures with minimized energies. Calculated potential energies and non-bond energies of these systems were used in the analysis and obtained findings were validated against available experimental data. Differences between the surfaces and edge of kaolinite with respect to the adsorption of molecules were observed and it was found that only surfaces and not the edge of kaolinite are preferred by the molecules. Although both surfaces show better adsorption capabilities than kaolinite edge, the tetrahedral surface showed stronger adhesion force to chlorhexidine than the octahedral surface. Results also show the influence of water and urea molecules on the chlorhexidine – kaolinite interactions. Molecular modeling based on the empirical force field seems to be useful tool for detailed analysis of organo/inorganic nanocomposite structures.