title: Contaminant-mobilizing capability of fullerene nanoparticles (nC60): Effect of solvent-exchange process in nC60 formation.
abstract: Fullerene nanoparticles (nC(60)) in aqueous environments can significantly enhance the transport of hydrophobic organic contaminants by serving as a contaminant carrier. In the present study, the authors examine the effect of the solvent-exchange process on nC(60) aggregate formation and, subsequently, on nC(60) 's contaminant-mobilizing capability. A series of nC(60) samples were prepared using a modified toluene-water solvent-exchange method through the inclusion of a secondary organic solvent in the phase transfer of molecular C(60) in toluene to nC(60) in water. Two groups of solvents--a water-miscible group and a non-water-miscible group-of varied polarity were selected as secondary solvents. The involvement of a secondary solvent in the phase transfer process had only small effects on the particle size and distribution, ζ potential, and mobility of the nC(60) products but significantly influenced the capability of nC(60) to enhance the transport of 2,2',5,5'-polychlorinated biphenyl (PCB) in a saturated sandy soil column, regardless of whether the secondary solvent was water-miscible or non-water-miscible. The two groups of secondary solvents appear to affect the aggregation properties of nC(60) in water via different mechanisms. In general, nC(60) products made with a secondary water-miscible solvent have stronger capabilities to enhance PCB transport. Taken together, the results indicate that according to formation conditions and solvent constituents, nC(60) will vary significantly in its interactions with organic contaminants, specifically as related to adsorption or desorption as well as transport in porous media.
authors.affiliation: College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin, China.
authors.forename: Lilin
authors.initials: L
authors.lastname: Wang
authors.forename: John D
authors.initials: JD
authors.lastname: Fortner
authors.forename: Lei
authors.initials: L
authors.lastname: Hou
authors.forename: Chengdong
authors.initials: C
authors.lastname: Zhang
authors.forename: Amy T
authors.initials: AT
authors.lastname: Kan
authors.forename: Mason B
authors.initials: MB
authors.lastname: Tomson
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D037741:Fullerenes / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D011078:Polychlorinated Biphenyls / Q000737:chemistry; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D014050:Toluene / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D012987:Soil; D012989:Soil Pollutants; D012997:Solvents; D014050:Toluene; D012822:Silicon Dioxide; D011078:Polychlorinated Biphenyls