Biocompatible rapid few-layers-graphene synthesis in aqueous lignin solutions. (April 2022)

• Record Type: Journal Article
• Authors: Marchi, Claudio; Loh, Harrison A.; Lissandrello, Federico; Lucotti, Andrea; Sierros, Konstantinos A.; Magagnin, Luca
• Is Part Of: Carbon trends. Number 7(2022)
• Publication Date: 2022-04
• Subjects: Graphene -- Graphite -- Liquid Phase Exfoliation -- Ultrasounds -- Lignin; Carbon -- Periodicals; Carbon composites -- Periodicals; Carbon; Carbon composites; Periodicals; 620.193
• DOI: 10.1016/j.cartre.2022.100169
• Languages: English
• ISSNs: 2667-0569

Abstract

Highlights: Alkali lignin is an effective stabilizer for rapid exfoliation of graphene Raman data mapping provides insight on the effect of process parameters on graphene 3-5 layers graphene with low-defectivity is obtained within 3 hours of sonication Abstract: Ultrasonic-Assisted Liquid Phase Exfoliation (UALPE) is considered one of the most promising approaches for the scale-up of graphene production. The process is based on the isolation and stabilization of layers of 2D materials, such as graphene: the selection of a proper stabilizing/exfoliating agent is crucial to achieve a stable Few-Layers-Graphene (FLG) dispersion. In the present work we propose the use of alkali lignin (AL) as a polymeric stabilizing agent for the rapid (≤ 3 hours) synthesis of FLG. Sonication time and graphite-to-lignin (Gr/AL) ratios were investigated as the primary operational parameters to identify the optimal working conditions. Spectroscopical characterization of the samples were employed to assess the quality of the synthesized material: the analysis of the Raman and XPS spectra provided insight on the number of layers and the nature of the limited defects introduced with the exfoliation procedure. Low-defectivity FLG was obtained at Gr/AL = 8 and a sonication time of 3 hours. Furthermore, Scanning Electron Microscopy and Dynamic Light Scattering were performed to investigate the size of the exfoliated flakes (∼ 400 nm). The procedure proposed represents a rapid route for the synthesis of FLG, which will be further explored for composites in chemiresistive devices. Graphical abstract: Image, graphical abstract