AVS 50th International Symposium
    Nanometer Structures Wednesday Sessions
       Session NS-WeM

Paper NS-WeM4
Evaluating Nanocomposite Strength at Individual Nanotube-Polymer Interfaces

Wednesday, November 5, 2003, 9:20 am, Room 308

Session: Nanomechanics
Presenter: S.R. Cohen, Weizmann Institute of Science, Israel
Authors: S.R. Cohen, Weizmann Institute of Science, Israel
A.H. Barber, Weizmann Institute of Science, Israel
C.A. Cooper, Weizmann Institute of Science, Israel
H.D. Wagner, Weizmann Institute of Science, Israel
Correspondent: Click to Email
Nanocomposites formed from carbon nanotubes have been proposed as an ultra-high strength material. Although bulk measurements of the properties of such nanocomposites support these claims, until this work the only direct microscopic investigation of the nanotube/polymer interfacial strength has been by theoretical predictions. We have developed two novel SPM-based techniques which measure, for the first time, the direct pull-out forces of individual nanotubes in a polymer matrix.@footnote 1@ In one approach, the nanotubes are mixed into an epoxy resin using a procedure which results in a porous structure with nanotubes bridging the pores and embedded into the polymer matrix. The SPM tip is used to drag these nanotubes out of a film formed by microtoming this structure. The force exerted is extracted from the SPM measurement, whereas embedded length is measured with the aid of TEM. In the second approach, a nanotube attached to an SPM probe is pushed into a polymer melt, and pulled out from the hardened polymer after cooling. Here, the SPM measurement is used to evaluate both the forces and embedded length. Our results verify the predicted high nanotube-polymer interfacial strength, and reveal trends correlated to fiber diameter and embedded length. @FootnoteText@ @footnote 1@ (a) Carole A. Cooper, Sidney R. Cohen, Asa H. Barber, and H. Daniel Wagner Appl. Phys. Lett. 81, 3873-75 (2002); (b) Asa H. Barber, Sidney R. Cohen, and H. Daniel Wagner Appl. Phys. Lett. (June, 2003) .