The Role of Reduced Graphene Oxide toward the Self-Assembly of Lignin-Based Biocomposites Fabricated from Ionic Liquids

Abstract

Lignin’s immiscibility with most polymers along with its unknown association behaviors are major factors that contribute to its disposal and processability for the production of materials. To fully utilize lignin, an improved understanding of its interaction with other materials is needed. In this study, we investigate the morphological and physicochemical properties upon the addition of reduced graphene oxide (rGO) as a function of material composition in a tertiary system comprised of lignin, cellulose and xylan. The main motivation for this work is to understand how the lignin molecule associates and behaves in the presence of other natural macromolecules, as well as with the addition of reduced graphene oxide. The fabricated biocomposites with and without rGO were investigated using Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), Scanning Electron Microscope (SEM) techniques, Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC). The results demonstrated that the regenerated films’ structural, morphological and thermal character changed as a function of lignin-xylan concentration and upon the addition of rGO. We also observed a dramatic change in the glass transition temperature and topography. Final analysis showed that the addition of rGO prevented the macromolecules to self-assemble through a reduction of π-π aggregations and changes in the cellulose crystallinity.

Evaluation of the Compatibility of Organosolv Lignin-Graphene Nanoplatelets with Photo-Curable Polyurethane in Stereolithography 3D Printing

“…In comparison with lignin-polyurethane blends, the molecular structure of lignin tends to form a lignin-lignin interaction; the viscosity of the resin composite gradually increases as the composition of the lignin increases, as seen in Figure 1a. Unlike graphene oxide, which has a nanolayer formation, the graphene nanoplatelets particles require proper mechanical homogenization method to distribute in the polyurethane system [36,39,42]. Accordingly, the composition of lignin-graphene in polyurethane system facilitated greater distribution, significantly increasing the mechanical properties of the 3D-printed composites.…”

Fast pyrolysis of fig leaves: influence of pyrolysis parameters and characterization of bio-oil

“…Fig leaves exhibited a compact morphology, complex and very ordered in macrofibrils. Lignocellulosic blends interact via intermolecular hydrogen bonding, preventing the material to self-assemble [33]. 2 shows SEM-EDS photograph of the FL.…”