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Int. J. Materials and Product Technology, Vol. 27, Nos. 1/2, 2006
Synthesis of nanoparticles of tantalum (V) oxide in presence of D-galactose 3,6 anhydro-L-galactose Humberto A. Monreal* and Alberto M. Villafañe Research Center in Advanced Materials, S.C, Miguel de Cervantes, No. 120 Industrial Complex, 31109 Chihuahua Chih. Mexico, USA E-mail:
[email protected] E-mail:
[email protected] *Corresponding author
Jose G. Chacon-Nava Research Center in Advanced Materials, S.C., Miguel de Cervantes No. 120 Industrial Complex, 31120 Chihuahua chih, México, USA E-mail:
[email protected]
Perla E. García and Carlos A. Martínez Institute of Engineering and Technology, U.A.C.J. Avenue of the Charro, No. 450 North Cd Juarez, Chih. Mexico, USA E-mail:
[email protected] E-mail:
[email protected] Abstract: In this work tantalum oxide nanoparticles were synthesised by controlled hydrolysis of tantalum ethoxide in presence of a linear polysaccharide (1-3 linked -D galactapyranose and 1,4 linked 3,6 anyhdro- -L-galactopyranose). Nanoparticles of 100 – 600 nm were obtained when the polysaccharide was used. The nanoparticles were characterised by Scanning electron microscopy (SEM), and retrodispersive energy spectroscopy (EDAX). Keywords: polysaccharide; molecular biology; tantalum ethoxide; agarosa; sol-gel process. Reference to this paper should be made as follows: Monreal, H.A., Villafañe, A.M., Chacon-Nava, J.G., García, P.E. and Martínez, C.A. (2006) ‘Synthesis of nanoparticles of tantalum (V) oxide in presence of D-galactose 3,6 anhydro-L-galactose’, Int. J. Materials and Product Technology, Vol. 27, Nos. 1/2, pp.80–84.
Copyright © 2006 Inderscience Enterprises Ltd.
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Biographical notes: Humberto A. Monreal is a PhD Candidate in Materials Science at the Advanced Materials Research Center, CIMAV, (Mexico) He has worked in the areas of Nanotechnology and Bionanotechnology in the Institutional Program of Nanotechnology at CIMAV, where part of his work is related with the synthesis of nanostructured materials with DNA, aminoacids, proteins and polysaccharides. He has a MSc in Biotechnology from Faculty of Chemistry at the University of Chihuahua, (UACH) Mexico. Alberto Martinez Villafane is a Scientific Researcher at the Advanced Materials Research Center, CIMAV, (Mexico). He is the Head of the Materials Physics Department, and works in the areas of high-temperature processes, materials engineering, metallic coatings and nanostructures. He has a MSc in Physics from the National Polytechnic Institute, IPN, Mexico, and a PhD from UMIST, England. He is a collaborator in the Institutional Program of Nanotechnology at CIMAV, and is a consultant for CONACyT in Mexico. Jose G. Chacon-Nava is a Scientific Researcher at the Advanced Materials Research Center, CIMAV, (Mexico). He has 22 years of experience in the areas of high-temperature corrosion and materials engineering. He has a BSc in Chemical Engineering from Instituto Tecnologico y de Estudios Superiores de Occidente, Guadalajara, Mexico, and a MSc and PhD from UMIST. Actually, he is a collaborator in the Institutional Program of Nanotechnology at CIMAV, where part of his work is related with the synthesis and characterisation of nanocompounds. Perla E. Garcia is a Scientific Researcher at the University of Juarez. She has MSc and PhD from Advanced Materials Research Center, CIMAV, (Mexico). Actually, she is a collaborator in the Institutional Program of Nanotechnology at CIMAV, his work is related with the synthesis and characterisation of nanostructured materials. Carlos A. Martinez is a Scientific Researcher at the University of Juarez. He has a MSc in Biomaterials and a PhD from Advanced Materials Research Center, CIMAV, (Mexico), is a collaborator in the Institutional Program of Nanotechnology at CIMAV. His work is related with the synthesis and characterisation of nanostructured materials.
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Introduction
Materials in the nanometer size have attracted considerable attention because of their novel properties and applications unlike those of conventional macroscopic materials. Transition metal oxides such as tantalum, titanium, and vanadium oxides are generally accepted as the next-generation materials in the fields such as electronics (Patrissi and Martin, 1999) and advanced catalysts (Takahara et al., 2001). Many efforts have been made to control nanostructures of transition metal oxides using replication processes (Muster et al., 2000), chemical processes (Zhu et al., 2001) and template techniques (Antonelli and Ying, 1996). These processes have been focused in the synthesis of titanium dioxide, and others transitions metal oxides like tantalum (V) oxide have also been looked into. This contribution describes a route to the preparation of tantalum (V) oxide nanoparticles by a sol-gel process using a polysaccharide as agent for the size and morphology control.
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Experimental procedure
To obtain a 0.8% (w/v), 0.2 g of D-galactose 3,6 anhydro-L-galactose grade molecular biology molecules was added to dionized H2O. Then 100 µl of the solution was heated at 40°C for 30 minutes. Then 200 µl of ethanol was added followed by addition of 200 µl (0.77 mmol) of tantalum ethoxide drop by drop under vigorous stirring for 15 minutes. The solution was centrifuged at 12,000 rpm and washed with dionized water three times. Finally, the particles were calcinated at 800°C for three hours. The characterisation was made by scanning electron microscopy (SEM) using a JEOL JSM-5800 LV, and electron dispersive energy (EDAX). See Figure 1. Figure 1
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Structure of D-galactose and 3,6–anhydro-a-L-galactose
Results and discussion
In this paper, an easy route to obtain tantalum (V) oxide nanoparticles is presented. In Figure 2(a), we can see a conglomerate of tantalum (V) oxide nanoparticles where the homogeneity of the particles can be appreciated. They have a spherical morphology and a size in the order of 100 nm attributable to the polymeric mesh of the agarose gel in the liquid phase which prevents the growing of the particles in a disorganised way; this reflects the precision of the used methodology. On the other hand, when the experiment was run without the presence of agarose gel, irregular structures were obtained as can be seen in Figure 2(b). In Figure 3, we can see a quantitative microanalysis of tantalum and other present elements in the sample by EDAX, the percentage in weight for the different elements are 83 wt% of Ta that correspond to the highest peak of the spectrum, and 17 wt% of Oxygen. In the present work, Ta2O5 nanoparticles were obtained by an easy route; the size control of the particles is attributed to the stability of the formation of an agarose polymeric mesh during the phase of condensation which does not allow a disorganised growing of the particles since the mesh acts like a barrier to the enhancing the nanometer size of the particles. The parameters optimisation is actually under investigation and it will be presented in a future publication.
Synthesis of nanoparticles of tantalum (V) oxide Figure 2
SEM pictures of (a) Ta2O5 nanoparticles in presence of the polysaccharide and (b) tantalum (V) oxide without polysaccharide
(a)
(b) Figure 3
EDAX spectrum of the Ta2O5 nanoparticles
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Conclusions
Tantalum (V) oxide nanoparticles in the range of 100–600 nm were obtained by a sol-gel process facilitated by the presence of linear polysaccharide. This method is an easy route to obtain Ta2O5 nanoparticles and could be extended towards the synthesis of others transition metal oxides.
Acknowledgements This research was supported by the Research Centre Advanced Materials S.C. and the Institute of Engineering and Technology, University of Juarez, Chihuahua, Mexico.
References Antonelli, D.M. and Ying, J.Y. (1996) ‘Syntehesis and characterization of hexagonally packed mesoporous tantalum oxide molecular sieves’, Chem. Mater., Vol. 8, p.874. Muster, J., Kim, G.T., Krstic, V., Park, J.G., Park, Y.W., Roth, S. and Burghard, M. (2000) ‘Electrical transport through individual vanadium pentoxide nanowires’ Adv. Mater., Vol. 12, p.420. Patrissi, C. and Martin, C. (1999) ‘Sol-gel- based template synthesis and li-insertion rate performance of nanostructured vanadium pentoxide’, J. Electro Chem. Soc., Vol. 146, p.3176. Takahara, Y., Condo, J.N., Takata, T., Lu, D. and Domen, K. (2001) ‘Mesoporous tantalum oxide. 1. Characterization and photocatalytic activity for the overall water decomposition’, Chem. Mater., Vol. 13, p.1194. Zhu, Y., Li, H., Koltyping, Y., Hacohme, Y.R. and Gedanken, A. (2001) ‘Sonochemical synthesis of Titania whiskers and nanotubes’ Chem. Commun., Vol. 124, p.2616.
