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Tailoring Graphene to Withstand Large Deformations (Tailor Graphene)
Date du début: 1 juin 2013, Date de fin: 31 mai 2018 PROJET  TERMINÉ 

This proposal aims via a comprehensive and interdisciplinary programme of research to determine the full response of monolayer (atomic thickness) graphene to extreme axial tensional deformation up to failure and to measure directly its tensile strength, stiffness, strain-to-failure and, most importantly, the effect of orthogonal buckling to its overall tensile properties. Already our recent results have shown that graphene buckling of any form can be suppressed by embedding the flakes into polymer matrices. We have indeed quantified this effect for any flake geometry and have produced master curves relating geometrical aspects to compression strain-to-failure. In the proposed work, we will make good use of this finding by altering the geometry of the flakes and thus design graphene strips (micro-ribbons) of specific dimensions which when embedded to polymer matrices can be stretched to large deformation and even failure without simultaneous buckling in the other direction. This is indeed the only route possible for the exploitation of the potential of graphene as an efficient reinforcement in composites. Since orthogonal buckling during stretching is expected to alter- among other things- the Dirac spectrum and consequently the electronic properties of graphene, we intend to use the technique of Raman spectroscopy to produce stress/ strain maps in two dimensions in order to quantify fully this effect from the mechanical standpoint. Finally, another option for ironing out the wrinkles is to apply a simultaneous thermal field during tensile loading. This will give rise to a biaxial stretching of graphene which presents another interesting field of study particularly for already envisaged applications of graphene in flexible displays and coatings.

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