BENKO Aleksandra AGH University of Science and Technology

EPD as a Potential Fractioning Tool for Carbon Nanotubes

Co-authors NOCUŃ Marek, Wyrwa Jan, BŁAŻEWICZ Marta

Despite many interesting properties i.e. high mechanical strength [1] good thermal [2, 3] and electrical conductivity [4], the usage of carbon nanotubes in many fields of science or industry, including biomedical applications, is still limited by very low repeatability of the properties of the tubes within the stock sample. Furthermore, many producers offer products that may significantly differ in quality and actual properties, despite similar datasheets [5, 6]. This fact yields many contradicting reports, concerning both biocompatibility and basic materials’ properties [7, 8]. In the literature, fractioning of the CNTs, altering in sizes or different level of chemical modification, is reported, pointing out potential applicability of electrophoresis [9]. We suggest a different approach, which enables simultaneous fractioning and layer fabrication, using Electrophoretic Deposition. In the proposed method it is possible to obtain layers with different surface properties, which are determinants of materials’ cytotoxicity. The aim of this study was to test a potential applicability of the EPD method as a fractioning tool for carbon nanotubes. We report functionalization of the CNTs in the mixture of concentrated acids, preparation of a stable suspension in the acetone and ethanol solution and successful deposition of dense layers by means of the EPD, with varying times. The obtained materials are characterized via goniometer, XPS and EIS. It is proven that with increasing time of deposition, different CNTs individuals are deposited on the material, altering in type and amount of functional groups. Furthermore, with increasing thickness of the layer, character of electrical conductivity changes significantly. ACKNOWLEDGEMENTS: This research has been supported by the National Center of Science (NCN) under grants: UMO-011/01/B/ST5/06424 and UMO-2013/11/N/ST8/01357 LITERATURE: [1] Demczyk, B.G., et al., Direct mechanical measurement of the tensile strength and elastic modulus of multiwalled carbon nanotubes. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing, 2002. 334(1-2): p. 173-178. [2] Han, Z.D. and A. Fina, Thermal conductivity of carbon nanotubes and their polymer nanocomposites: A review. Progress in Polymer Science, 2011. 36(7): p. 914-944. [3] Berber, S., Y.K. Kwon, and D. Tomanek, Unusually high thermal conductivity of carbon nanotubes. Phys Rev Lett, 2000. 84(20): p. 4613-6. [4] Przekora, A., et al., Titanium coated with functionalized carbon nanotubes — A promising novel material for biomedical application as an implantable orthopaedic electronic device. Materials Science and Engineering: C, 2014. 45(0): p. 287-296. [5] Levine, K., et al., Characterization of an assortment of commercially available multiwalled carbon nanotubes. Microchimica Acta, 2014. 181(1-2): p. 171-179. [6] Tessonnier, J.-P., et al., Analysis of the structure and chemical properties of some commercial carbon nanostructures. Carbon, 2009. 47(7): p. 1779-1798. [7] Beg, S., et al., Advancement in carbon nanotubes: basics, biomedical applications and toxicity. J Pharm Pharmacol, 2011. 63(2): p. 141-63. [8] Fraczek-Szczypta, A., Carbon nanomaterials for nerve tissue stimulation and regeneration. Mater Sci Eng C Mater Biol Appl, 2014. 34: p. 35-49. [9] Bobrinetskii, I.I., Electrophoresis in the tasks of purifying, separating, and integrating carbon nanotubes. Nanotechnologies in Russia, 2009. 4(1-2): p. 55-59.