title: C60-DOM interactions and effects on C60 apparent solubility: a molecular mechanics and density functional theory study.
abstract: Dissolved organic matter (DOM) plays a critical role in the transport of carbon nano-particles (e.g. C(60)) in the aquatic environment. However, the mechanism for C(60)-DOM interactions and its environmental implications needs further investigations. In this study, the interaction of C(60) with relevant reference compounds of DOM (DOM(R)) is computationally simulated by molecular mechanics and density functional theory (DFT). All the C(60)-DOM(R) complexes are firstly optimized by classical annealing, and then DFT using the Dmol(3) code. The adsorption energies of C(60) on DOM(R) were computed. The computed electrostatic potential indicates that DOM(R) are electron acceptors in the C(60)-DOM(R) complexes, and the thermodynamic calculations indicate that electrostatic interaction is the dominant driving force for the C(60)-gallic acid complexation process in water. The presence of DOM(R) increases the apparent water solubility of C(60). It is also observed that the C(60) apparent water solubility decrease with the increase of the energy gaps of frontier molecular orbitals (E(LUMO)-E(HOMO)) for each C(60)-DOM(R) complex. These findings indicate that computational simulation is an important tool for predicting the behavior and fate of carbon nano-particles in the aquatic environment.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, PR China.
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Wang
authors.forename: Jingwen
authors.initials: J
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Sun
authors.forename: Willie J G M
authors.initials: WJ
authors.lastname: Peijnenburg
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D037741:Fullerenes / Q000737:chemistry*; D005707:Gallic Acid / Q000737:chemistry; D006812:Humic Substances; D007700:Kinetics; D008958:Models, Molecular; D012995:Solubility; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D006812:Humic Substances; D014874:Water Pollutants, Chemical; D014867:Water; D005707:Gallic Acid; D002244:Carbon; C069837:fullerene C60