Abstract:

The cluster models Si₁₃O₃₇H₂₂ and Al₆O₂₄H₃₀ for tetrahedral(Si-O) and octahedral(Al-O) surfaces of kaolinite were constructed, respectively. The properties of interaction between 1,3,5-trinitrobenzene(TNB) molecule and kaolinite surface have been studied at the levels of B3LYP/6-31G(d), MP2/6-31G(d)//B3LYP/6-31G(d) and B3LYP/6-311++G(d,p)//B3LYP/6-31G(d), respectively. The computed properties characterizing complexes include optimal structures, structural parameters, adsorption energies, vibration frequencies, electrostatic potential maps, molecular orbitals, and so on. The results show that the interaction of TNB with the Si-O surface is governed by the electrostatic and van der Waals' interactions, and the interaction between TNB and Al-O surface is mainly provided by the hydrogen bonds. Simultaneously the binding energy between TNB molecule and Al-O surface is lower than that between TNB molecule and Si-O surface.

Key words: 1,3,5-Trinitrobenzene, Kaolinite, Adsorption, Hydrogen bond, Molecular orbital