Universidad Nacional Autónoma de México - CNyN

1st International Symposium on Nanoscience and Nanomaterials
developed on the metal powder. This material was introduced in a suspension of Ca(OH) 2 and was added
phosphoric acid in a stoichiometric proportion to growth the hydroxyapatite phase on titanium particles.
Once the reaction was finished we aged the solution, subsequently the powders were, washed , filtered and
dried and studied by x ray diffraction pattern we observed two principal features an improvement of the
cristallinity as function of the treatment of the titanium and the small size of the nanocystalline composite
powder hydroxyapatite – titanium formed. The powders obtained were pressed and sintered, the material
showed hardness was in the order of 450HV200 by x ray technique we observed the development of a
vitreous phase in the sintered material. By this methodology we arrived to a nanocomposite powder whose
characteristics favors its possible use in future studies, it means, by the control of the quantity and
composition of components it is possible to develop functionally graded materials.
P-019
ELECTRICAL PROPERTIES OF THE MULTIWALL CARBON NANOTUBES BUNDLES IN
GLASS TUBING
U. J. Tamayo-Perez 1a , A. Martínez-Ruíz 1b
1 Facultad de Ciencias, Universidad Autónoma de Baja California, Km. 103 Carretera Tijuana-Ensenada, C.P.
22800, Baja California, México
Keywords: bulk Resistivity MWCNT Density bundles
a uli1234567@gmail.com, b alejandro@uabc.edu.mx
Since the discovery of carbon nanotubes (CNTs) by Iijima[1], have been intensively investigated for
their outstanding physical and chemical properties. There are some technical difficulties of electrical
resistivity measurements on an individual CNT, as well as the results are very sample-dependent. The
electrical properties and the associated measurement techniques of bulk; bundles, ribbons or ropes of CNTs
provide an alternative approach to study a macroscopic scale of both basic science and applications of CNTs
[2]. In this work, a mass known of MWNTs have been placed into the insulating glass cylinder at room
temperature where it is compacted for metal electrodes reducing the volume of the bundle, with advances of
066µm, in each advances the density is increases and the resistance decreases between two electrodes. Under
the maximum compressive stress of 109 MPa the measurements of bulk of MWNTs as the Ohmic I–V
characteristic. This new methodology not only provides an effective path to measurement electrical properties
is the way to characterization in spongy regime for potential applications as gas sensors [3-4].
Acknowledgments: This work is partially supported through a student grant from CONACyT. We thank to
Dr. Gerardo Soto H., Dr. José Valenzuela B. and Ing. Israel Gradilla M. from CNyN-UNAM for helpful
discussions and assistance with the experiments.
[1]S. Iijima, Nature 354 (1991) 56.
[2] R.Z. Ma, C.L. Xu, B.Q.Wei, J. Liang, D.H.Wu, D.J. Li, Mater. Res. Bull. 34 (1999) 741.
[3] P. Singjai ∗ , S. Changsarn, S. Thongtem, Materials Science and Engineering A 443 (2007) 42–46.
[4] Woo-Sung Cho, Seung-Il Moon, Yang-Doo Lee, IEEE Electron Device Letters, VOL. 26, NO. 7, July 2005.
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