PDF Publication Title:
Text from PDF Page: 088
Chapter 3 β Raman Spectroscopy of Graphene and Graphene-based Strain Sensors The shear-lag analysis have been extended and adapted for CVD graphene as reported by Li et al.281 They have studied the deformation of CVD graphene on PET substrates which had wrinkles in the order of ~1.2 ΞΌm domains (graphene islands, Figure 3.10a). The observed 2D band shift rate of such system was ~ -12.8 cm-1/% strain (Figure 3.10b), as opposed to ~ -52.5 cm-1/% strain288 for flat MC SLG on PET. This lower shift rate, according to shear-lag theory, is due to the short fibre effect (Figure 3.10c). In this case, despite having a fairly good interface between PET and the CVD graphene, each graphene island acts as a short fibre, smaller than the ππ, such that the stress transfer is non uniform (Figure 3.10d) within the islands leading to lower shift rates.281 Figure 3.10: a) SEM image of CVD graphene showing the graphene islands (wrinkles). b) Shift rate of 2D band under uniaxial strain. c) Schematic diagram explaining the short fibre effect in CVD graphene system with wrinkles. d) Predicted strain distribution within ~1.2 ΞΌm diameter graphene island for applied PET strain of 0.4 %.281 Such lower shift rates upon straining was not reported by Bissett et al. who investigated Raman band shifts of CVD graphene on PDMS, and reported a 2D band shift rate of ~ -72 cm-1/% strain.277 It has to be noted that they have used more deformable PDMS substrate (πππ·ππβ 0.5) than Li et al.281 (PET, πππΈπβ 0.35), that could have induced a biaxial strain. Moreover, they have assumed the MC SLG and CVD SLG would have same 88PDF Image | PRODUCTION AND APPLICATIONS OF GRAPHENE AND ITS COMPOSITES
PDF Search Title:
PRODUCTION AND APPLICATIONS OF GRAPHENE AND ITS COMPOSITESOriginal File Name Searched:
graphene-production-applications.PDFDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Power up your energy storage game with Salgenx Salt Water Battery. With its advanced technology, the flow battery provides reliable, scalable, and sustainable energy storage for utility-scale projects. Upgrade to a Salgenx flow battery today and take control of your energy future.
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |