Multiscale and multidimensional characterisation of graphene-related nanomaterials and nanocomposites
Topic(s) : Material science
Co-authors :
Yuhan LI (UNITED KINGDOM), Milo S. P. SHAFFER (UNITED KINGDOM)Abstract :
Macroscale assemblies and composite structures, built upon graphene and graphene-related nanomaterials, are promising for a range of applications and devices. Consequently, there is growing demand for more comprehensive characterisation of graphene-based structures. The primary challenges revolve around understanding the morphology, dispersion, and spatial arrangement of the individual graphene flakes, as well as their interactions with other material phases. This presentation presents multiscale and multidimensional characterisation methodologies for investigating various graphene-based structures, employing a combination of optical and electron microscopy techniques, image processing and analytical methods.
Confocal laser scanning microscopy (CLSM) is developed as a valuable tool for microstructural investigation of graphene nanomaterials and nanocomposites, exploiting the technique’s distinctive features, including high-contrast and non-invasive imaging, as well as depth discrimination. Using confocal reflection and total interference contrast imaging, the flake thickness distribution in graphene oxide (GO) films can be mapped rapidly and quantitatively. In addition to passive characterisation, CLSM can be used for simultaneous imaging and processing studies [1]: GO films can be selectively reduced in-situ to produce electrically conductive functional patterns at a range of lengthscales from millimetre to sub-micron. The versatility is demonstrated by direct writing “RC” circuits using the simple low power laser within the CLSM. Multi-modal tracking allows the conversion mechanism to be explored during the process. Controlled ablations allows 3D architectures to be written directly.
Full characterisation of graphene dispersion, particularly in nanocomposites, requires methods for volumetric characterisation; a variety of complementary 3D imaging methodologies are therefore developed. Non-destructive CLSM stack imaging, using reflection and fluorescence modalities, is applied for large-scale examination of graphene nanocomposites. General guidelines are established through discussions of applicability, sample requirements and imaging conditions. 3D characterisation methods based on destructive, serial array tomography are developed, enabling correlative optical and electron microscopic imaging. Multiscale correlative characterisation is demonstrated to be highly significant in extracting rich structural details, unveiling the local organisation, flake orientation, and morphology of various graphene nanocomposites. The availability of 3D datasets provides exciting opportunities to quantify structural features (see Figure 1), as demonstrated through statistical dispersion and distribution analysis of functionalised graphene nanocomposites. This study provides valuable insights into the real structure of graphene films and nanocomposites; the methodologies developed will be widely applicable in the nanomaterials field.
Confocal laser scanning microscopy (CLSM) is developed as a valuable tool for microstructural investigation of graphene nanomaterials and nanocomposites, exploiting the technique’s distinctive features, including high-contrast and non-invasive imaging, as well as depth discrimination. Using confocal reflection and total interference contrast imaging, the flake thickness distribution in graphene oxide (GO) films can be mapped rapidly and quantitatively. In addition to passive characterisation, CLSM can be used for simultaneous imaging and processing studies [1]: GO films can be selectively reduced in-situ to produce electrically conductive functional patterns at a range of lengthscales from millimetre to sub-micron. The versatility is demonstrated by direct writing “RC” circuits using the simple low power laser within the CLSM. Multi-modal tracking allows the conversion mechanism to be explored during the process. Controlled ablations allows 3D architectures to be written directly.
Full characterisation of graphene dispersion, particularly in nanocomposites, requires methods for volumetric characterisation; a variety of complementary 3D imaging methodologies are therefore developed. Non-destructive CLSM stack imaging, using reflection and fluorescence modalities, is applied for large-scale examination of graphene nanocomposites. General guidelines are established through discussions of applicability, sample requirements and imaging conditions. 3D characterisation methods based on destructive, serial array tomography are developed, enabling correlative optical and electron microscopic imaging. Multiscale correlative characterisation is demonstrated to be highly significant in extracting rich structural details, unveiling the local organisation, flake orientation, and morphology of various graphene nanocomposites. The availability of 3D datasets provides exciting opportunities to quantify structural features (see Figure 1), as demonstrated through statistical dispersion and distribution analysis of functionalised graphene nanocomposites. This study provides valuable insights into the real structure of graphene films and nanocomposites; the methodologies developed will be widely applicable in the nanomaterials field.