Towards Efficient Dispersion of Carbon Nanotubes in Thermotropic Liquid Crystals

Authors

  • Stefan Schymura,

    1. Martin Luther University Halle-Wittenberg, Institute of Chemistry – Physical Chemistry, Von-Danckelmann-Platz 4, 06120 Halle (Germany)
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  • Martin Kühnast,

    1. Martin Luther University Halle-Wittenberg, Institute of Chemistry – Physical Chemistry, Von-Danckelmann-Platz 4, 06120 Halle (Germany)
    2. ENEA C. R. Portici, 80055 Portici (NA) (Italy)
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  • Vanessa Lutz,

    1. Martin Luther University Halle-Wittenberg, Institute of Chemistry – Organic Chemistry, Kurt-Mothes Straße 2, 06120 Halle (Germany)
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  • Stefan Jagiella,

    1. Martin Luther University Halle-Wittenberg, Institute of Chemistry – Organic Chemistry, Kurt-Mothes Straße 2, 06120 Halle (Germany)
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  • Ursula Dettlaff-Weglikowska,

    1. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany and Korea University, School of Electrical Engineering, Anam-Dong,136—713, Seoul (Korea)
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  • Siegmar Roth,

    1. Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany and Korea University, School of Electrical Engineering, Anam-Dong,136—713, Seoul (Korea)
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  • Frank Giesselmann,

    1. University of Stuttgart, Institute for Physical Chemistry, Pfaffenwaldring 55, 70569 Stuttgart (Germany)
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  • Carsten Tschierske,

    1. Martin Luther University Halle-Wittenberg, Institute of Chemistry – Organic Chemistry, Kurt-Mothes Straße 2, 06120 Halle (Germany)
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  • Giusy Scalia,

    Corresponding author
    1. ENEA C. R. Portici, 80055 Portici (NA) (Italy)
    • ENEA C. R. Portici, 80055 Portici (NA) (Italy).
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  • Jan Lagerwall

    Corresponding author
    1. Martin Luther University Halle-Wittenberg, Institute of Chemistry – Physical Chemistry, Von-Danckelmann-Platz 4, 06120 Halle (Germany)
    • Martin Luther University Halle-Wittenberg, Institute of Chemistry – Physical Chemistry, Von-Danckelmann-Platz 4, 06120 Halle (Germany)
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Abstract

Motivated by numerous recent reports indicating attractive properties of composite materials of carbon nanotubes (CNTs) and liquid crystals (LCs) and a lack of research aimed at optimizing such composites, the process of dispersing CNTs in thermotropic LCs is systematically studied. LC hosts can perform comparably or even better than the best known organic solvents for CNTs such as N-methyl pyrrolidone (NMP), provided that the dispersion process and choice of LC material are optimized. The chemical structure of the molecules in the LC is very important; variations in core as well as in terminal alkyl chain influence the result. Several observations moreover indicate that the anisotropic nematic phase, aligning the nanotubes in the matrix, per se stabilizes the dispersion compared to a host that is isotropic and thus yields random tube orientation. The chemical and physical phenomena governing the preparation of the dispersion and its stability are identified, taking into account enthalpic, entropic, as well as kinetic factors. This allows a guideline on how to best design and prepare CNT–LC composites to be sketched, following which tailored development of new LCs may take the advanced functional material that CNT–LC composites comprise to the stage of commercial application.

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