title: Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon.
abstract: The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was studied. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6±0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.
authors.affiliation: Department of Physics, Florida Atlantic University, Boca Raton, FL 33431, United States. Electronic address: skhanal2@fau.edu.
authors.forename: S P
authors.initials: SP
authors.lastname: Khanal
authors.affiliation: Department of Ocean and Mechanical Engineering, Florida Atlantic University, Boca Raton, FL 33431, United States.
authors.forename: H
authors.initials: H
authors.lastname: Mahfuz
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States.
authors.forename: A J
authors.initials: AJ
authors.lastname: Rondinone
authors.affiliation: Department of Physics, Florida Atlantic University, Boca Raton, FL 33431, United States.
authors.forename: Th
authors.initials: T
authors.lastname: Leventouri
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009757:Nylons / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D037742:Nanotubes, Carbon; D009757:Nylons; D017886:Durapatite
keywords: Fracture toughness; Hydroxyapatite (HAp); Nanocomposites; Single walled carbon nanotubes (SWCNTs)