title: Complex interplay between formation routes and natural organic matter modification controls capabilities of C60nanoparticles (nC60) to accumulate organic contaminants.
abstract: Accumulation of organic contaminants on fullerene nanoparticles (nC60) may significantly affect the risks of C60in the environment. The objective of this study was to further understand how the interplay of nC60formation routes and humic acid modification affects contaminant adsorption of nC60. Specifically, adsorption of 1,2,4,5-tetrachlorobenzene (a model nonionic, hydrophobic organic contaminant) on nC60was greatly affected by nC60formation route - the formation route significantly affected the aggregation properties of nC60, thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism. Depending on whether nC60was formed via the "top-down" route (i.e., sonicating C60powder in aqueous solution) or "bottom-up" route (i.e., phase transfer from an organic solvent) and the type of solvent involved (toluene versus tetrahydrofuran), modification of nC60with Suwannee River humic acid (SRHA) could either enhance or inhibit the adsorption affinity of nC60. The net effect depended on the specific way in which SRHA interacted with C60monomers and/or C60aggregates of different sizes and morphology, which determined the relative importance of enhanced adsorption from SRHA modification via preventing C60aggregation and inhibited adsorption through blocking available adsorption sites. The findings further demonstrate the complex mechanisms controlling interactions between nC60and organic contaminants, and may have significant implications for the life-cycle analysis and risk assessment of C60.
authors.affiliation: College of Environmental Science and Engineering, Southwest Forestry University, Kunming 650224, China; College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: houlei_1985@126.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Hou
authors.affiliation: Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, MO 63130, USA.
authors.forename: John D
authors.initials: JD
authors.lastname: Fortner
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Ximeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Chengdong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Lilin
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: chenwei@nankai.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D037741:Fullerenes / Q000737:chemistry*; D006812:Humic Substances; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D006812:Humic Substances; D014874:Water Pollutants, Chemical
keywords: Adsorption; Aggregation; Fullerene nanoparticles; Natural organic matter; Organic contaminants