A molecular dynamics study of the mechanical properties of hydrogen functionalized graphene

QX Pei and YW Zhang and VB Shenoy, CARBON, 48, 898-904 (2010).

DOI: 10.1016/j.carbon.2009.11.014

Molecular dynamics simulations have been performed to investigate the mechanical properties of hydrogen functionalized graphene for H-coverages spanning the entire range from graphene (H-0%) to graphane (H-100%). We find that the Young's modulus, tensile strength, and fracture strain of the functionalized graphene deteriorate drastically with increasing H-coverage up to about 30%. Beyond this limit the mechanical properties remain insensitive to H-coverage. While the Young's modulus of graphane is smaller than that of graphene by 30%, the tensile strength and fracture strain show a much larger drop of about 65%. We show that this drastic deterioration in mechanical strength arises both from the conversion of sp(2) to sp(3) bonding and due to easy-rotation of unsupported Sp(3) bonds. Our results suggest that the coverage-dependent deterioration of the mechanical properties must be taken into account when analyzing the performance characteristics of nanodevices fabricated from functionalized graphene sheets. (C) 2009 Elsevier Ltd. All rights reserved.

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