Strain cartography of bilayer graphene‐PDMS nanocomposites using Raman spectroscopy

Abstract Effective transmission of stress between fillers and the host matrix is instrumental in enhancing the properties of nanocomposites and optimizing filler reinforcement. This study delves into understanding stress transfer in materials, exploring the impact of synthesis methods and matrix materials through a comprehensive examination of a bilayer graphene (BLG)‐polydimethylsiloxane (PDMS) nanocomposite. BLG was synthesized via chemical exfoliation and subjected to various strain conditions within a PDMS matrix. A precisely controlled strain, ranging from 0% to 0.19%, was applied using a meticulous 4‐point bending method, monitored with a standard strain gauge. The study unveiled significant shifts in the Raman spectra's 2D band, indicating a direct linear relationship with applied strain. Utilizing contour mapping techniques on well‐defined Raman spectra and stress‐induced band shifts, we mapped strain distribution within the BLG layer. The results revealed a gradual increase in strain from the lower to the upper end of the BLG structure, resembling strain behaviors observed in differently shaped fibers. These compelling findings advance our understanding of strain dynamics within BLG‐PDMS nanocomposites, highlighting the crucial role of strain mapping methodologies in scrutinizing the material's structural response to deformation. Highlights The study reports successful synthesis of high‐quality bilayer graphene (BLG) using a chemical exfoliation method, as evidenced by the sharp 2D and G Raman peaks. Significant shifts in 2D band exhibited linear correlation between applied strain; observed within precise strain levels of 0% to 0.19%. Contour maps revealed a gradual increase in strain from the lower to the upper end of the BLG structure, akin to strain behaviors observed in differently shaped fibers.