Scalable and Sustainable Sorting and Processing of Semiconducting Carbon Nanotubes as Functional Materials

Single-walled carbon nanotubes (SWNTs) feature outstanding electronic (high carrier mobilities) and optical (narrow near-infrared absorption and emission) properties. To harness these properties for functional materials and devices, they must be separated into purely semiconducting, metallic or even single-chirality SWNTs. The currently available separation methods are either expensive, not scalable or require harmful chemicals and solvents. Likewise, the subsequent processing of SWNTs into optical probes for bio-imaging, sensors, electronic circuits or thermoelectrics is far from sustainable. Both issues have so far prevented the widespread application of SWNTs despite their excellent properties. These problems cannot be addressed by tweaking parameters but require new approaches that take scalability and the environmental impact of the applied materials and processes into account, explore alternatives and expand our knowledge about the interactions of SWNTs with their environment to optimize new methods from the beginning.SCALE-NT aims to(i) explore new methods for the dispersion, purification and sorting of SWNTs in benign solvents and with natural or bio-based dispersants; and scale-up these processes toward multi-gram amounts of sorted SWNTs in a sustainable manner. (ii) develop sustainable processes and materials for the fabrication of SWNT-based devices such as thin-film transistors on recyclable substrates, large-area thermoelectrics without harsh dopants, and biodegradable optical sensor arrays for organic pollutants based on tailored interactions with functionalized SWNTs. (iii) understand the interactions of SWNTs with their surroundings as required for sorting and optical sensing via advanced in-situ THz and near-infrared fluorescence spectroscopy.With these objectives, SCALE-NT will help to finally establish SWNTs not only as highly functional but also more sustainable materials.