Liang Sun et al 2008 Nanotechnology 19 455706 doi:10.1088/0957-4484/19/45/455706
Liang Sun1, Ray P S Han2,5, Jun Wang3 and C T Lim4
Show affiliationsWe present a strain gradient (SG) theory to explain the strongly inverse size dependence between the elastic modulus and fiber diameter in polymeric nanofibers. For centrosymmetric and isotropic materials we showed that the three length-scale parameters can be combined into a single parameter that can be used to predict the onset of the size-dependent trend when the fiber diameter is reduced past its critical size. To address the issue of whether the SG offers a plausible explanation of the size-dependent behavior we conducted a series of uniaxial tensile and static bending tests involving polycaprolactone nanofibers. Since the elastic modulus is highly sensitive to the fiber diameter, it is necessary to correct the experimental data to account for the lack of circularity in the cross-section of the real fiber. Additionally, we applied the SG model to study the size-dependent elastic properties of polypyrrole nanotubes. By approaching the SG theory from a dynamics point of view, our model is able to capture size-dependent effects in the mechanics of fine-scale materials for both static and dynamic responses.
62.25.-g Mechanical properties of nanoscale systems
81.40.Lm Deformation, plasticity, and creep
81.40.Jj Elasticity and anelasticity, stress-strain relations
Issue 45 (12 November 2008)
Received 7 July 2008, in final form 4 September 2008
Published 9 October 2008
Liang Sun et al 2008 Nanotechnology 19 455706
Y-F Xiao et al 2008 New J. Phys. 10 123013
G Løvhøiden and E Andersen 1990 Phys. Scr. 1990 228
M A Van Zeeland et al 2008 Plasma Phys. Control. Fusion 50 035009
Fabian Weise et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 215307
Yanwu Zhu et al 2008 Nanotechnology 19 325304
E Tassi et al 2008 Plasma Phys. Control. Fusion 50 085014
Subhas Ghosal et al 2009 New J. Phys. 11 055011
Pavel Groisman and Amber Soja 2007 Environ. Res. Lett. 2 045008
T.A. Casper et al 2007 Nucl. Fusion 47 825