Experimental and theoretical investigation on the interaction of carboxylic multi-walled carbon nanotubes with bisphenol AF

Abstract

Abstract The binding interaction of carboxylic multi-walled carbon nanotubes (MWCNTs-COOH) with bisphenol AF (BPAF) was investigated using molecular modeling, fluorescence spectroscopy and adsorption experiment. Density functional theory (DFT) calculations were also carried out to explain the electronic structure and the electronic transitions of BPAF. It was found that MWCNTs-COOH exhibited strong binding affinity with BPAF, and the adsorption equilibrium was arrived within 5 min following the pseudo-second-order model. MWCNTs-COOH is to be a good adsorbing material for BPAF. The hydrophobic interaction, π-π bonding and hydrogen bonds were mainly binding forces for the strong interaction of MWCNTs-COOH with BPAF. In addition, the COOH groups on carbon nanotubes play an important role in adsorption of BPAF. The putative binding modes of BPAF on MWCNTs-COOH included the insert binding mode and the surface binding mode. The binding ability of the insert binding mode is stronger than that of the surface binding mode The combination of experiment and theoretical calculation would find useful information of the adsorption of endocrine disrupting compounds by carbon nanotubes with functional groups.