Browsing by Author "Liberman, Lucy"

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    Surfactant-assisted individualization and dispersion of boron nitride nanotubes
    (Royal Society of Chemistry, 2019) McWilliams, Ashleigh D. Smith; Reyes, Carlos A. de los; Liberman, Lucy; Ergülen, Selin; Talmon, Yeshayahu; Pasquali, Matteo; A. Martí, Angel; Bioengineering; Chemical and Biomolecular Engineering; Chemistry; Materials Science and Nanoengineering
    Boron nitride nanotubes (BNNTs) belong to a novel class of material with useful thermal, electronic and optical properties. However, the study and the development of applications of this material requires the formation of stable dispersions of individual BNNTs in water. Here we address the dispersion of BNNT material in water using surfactants with varying properties. The surfactants were compared based on the quantity of BNNTs dispersed and the quality of the dispersions, as visualized by AFM and cryo-TEM. All surfactants produce dispersions of individualized or small bundles of BNNTs. Of the surfactants tested, high molecular weight, nonionic surfactants suspend the most BNNTs, while ionic surfactants remove the most h-BN impurities. The surfactant dispersions were further characterized by ensemble measurements, such as UV absorption and photoluminescence, dynamic light scattering (DLS), and zeta potential to investigate dispersion stability and quality. These techniques provide a facile strategy for testing future BNNT dispersions. The results of this study reveal that BNNT dispersions in aqueous solution can be tuned to fit a specific application through surfactant selection.
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    Versatile acid solvents for pristine carbon nanotube assembly
    (AAAS, 2022) Headrick, Robert J.; Williams, Steven M.; Owens, Crystal E.; Taylor, Lauren W.; Dewey, Oliver S.; Ginestra, Cedric J.; Liberman, Lucy; Ya’akobi, Asia Matatyaho; Talmon, Yeshayahu; Maruyama, Benji; McKinley, Gareth H.; Hart, A. John; Pasquali, Matteo; The Smalley Institute for Nanoscale Science and Technology; The Carbon Hub
    Chlorosulfonic acid and oleum are ideal solvents for enabling the transformation of disordered carbon nanotubes (CNTs) into precise and highly functional morphologies. Currently, processing these solvents using extrusion techniques presents complications due to chemical compatibility, which constrain equipment and substrate material options. Here, we present a novel acid solvent system based on methanesulfonic or p-toluenesulfonic acids with low corrosivity, which form true solutions of CNTs at concentrations as high as 10 g/liter (≈0.7 volume %). The versatility of this solvent system is demonstrated by drop-in application to conventional manufacturing processes such as slot die coating, solution spinning continuous fibers, and 3D printing aerogels. Through continuous slot coating, we achieve state-of-the-art optoelectronic performance (83.6 %T and 14 ohm/sq) at industrially relevant production speeds. This work establishes practical and efficient means for scalable processing of CNT into advanced materials with properties suitable for a wide range of applications.