title: Effects of polymer wrapping and covalent functionalization on the stability of MWCNT in aqueous dispersions.
abstract: The colloidal behavior of aqueous dispersions of functionalized multiwall carbon nanotubes (F-CNTS) formed via carboxylation and polymer wrapping with polyvinyl pyrrolidone (PVP) is presented. The presence of polymer on the nanotube surface provided steric stabilization, and the aggregation behavior of the colloidal system was quite different from its covalently functionalized analog. Based on hydrophobicity index, particle size distribution, zeta potential as well as the aggregation kinetics studied using time-resolved dynamic light scattering, the PVP wrapped CNT was somewhat less prone to agglomeration. However, its long-term stability was lower, and this was attributed to the partial unwrapping of the polyvinyl pyrrolidone layer on the CNT surface.
authors.affiliation: Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
authors.forename: Susana Addo
authors.initials: SA
authors.lastname: Ntim
authors.forename: Ornthida
authors.initials: O
authors.lastname: Sae-Khow
authors.forename: Frank A
authors.initials: FA
authors.lastname: Witzmann
authors.forename: Somenath
authors.initials: S
authors.lastname: Mitra
mesh_terms: D000327:Adsorption; D003102:Colloids / Q000737:chemistry; D004355:Drug Stability; D004655:Emulsions; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D011205:Povidone / Q000737:chemistry*; D014867:Water; D014877:Water Pollution, Chemical
chemical_list: D003102:Colloids; D004655:Emulsions; D037742:Nanotubes, Carbon; D011108:Polymers; D014867:Water; D011205:Povidone