title: Aggregation of fullerol C60(OH)24 nanoparticles as revealed using flow field-flow fractionation and atomic force microscopy.
abstract: The effects of solution pH and 1:1 electrolyte concentration on the aggregation behavior of fullerol C(60)(OH)(24) nanoparticles were investigated using flow field-flow fractionation (FlFFF). Particle separations were confirmed by examining FFF fractions using atomic force microscopy (AFM). Results showed that fullerol C(60)(OH)(24) nanoparticles remain stable at low salt concentration (0.001 M NaCl) and basic pH (pH 10). Changing the pH did not affect the size significantly, but increasing the salt concentration promoted some aggregation. Fullerol C(60)(OH)(24) nanoparticles did not form large clusters and reached a maximum size of at most several nanometers. Particle interaction analysis using the colloid interaction theory as described by the energetics of electrostatic repulsion and van der Waals attraction explained the differences in the colloidal stability of the fullerol C(60)(OH)(24) nanoparticles under different solution conditions.
authors.affiliation: Department of Metallurgical Engineering, University of Utah, 135 South 1460 East, Room 412, Salt Lake City, Utah 84112, USA. shoeleh.assemi@utah.edu
authors.forename: Shoeleh
authors.initials: S
authors.lastname: Assemi
authors.forename: Soheyl
authors.initials: S
authors.lastname: Tadjiki
authors.forename: Bogdan C
authors.initials: BC
authors.lastname: Donose
authors.forename: Anh V
authors.initials: AV
authors.lastname: Nguyen
authors.forename: Jan D
authors.initials: JD
authors.lastname: Miller