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Nanotubo gabriel artigo Nanotubo gabriel artigo Document Transcript

  • Copyright © 2013 American Scientific Publishers All rights reserved Printed in the United States of America Journal of Biomaterials and Tissue Engineering Vol. 3, 1–4, 2013 High Dispersivity Bacterial Cellulose/Carbon Nanotube Nanocomposite for Sensor Applications Gabriel Molina Olyveira1 ∗ , Ligia Maria Manzine Costa2 , and Pierre Basmaji3 1 Department of Physical Chemistry, UNESP/Araraquara, 14800-900, Brazil Department of Nanoscience and Advanced Materials-UFABC, Rua Santa Adélia, 166, Santo André-SP, 09291-170, Brazil 3 Innovatec’s-Biotechnology Research and Development, São Carlos-SP, 13560-042, Brazil 2 Bacterial cellulose (BC) has established to be a remarkably versatile biomaterial and can be used in wide variety of applied scientific endeavors, especially for medical devices. In fact, biomedical devices recently have gained a significant amount of attention because of increased interesting tissue-engineered products for both wound care and the regeneration of damaged or diseased organs. The architecture of BC materials can be engineered over length scales ranging from nano to macro by controlling the biofabrication process, besides, surface modifications bring a vital role in in vivo performance of biomaterials. In this work, bacterial cellulose fermentation was modified with carbon nanotubes for sensor applications and diseases diagnostic. SEM images showed that polymer modified-carbon nanotube (PVOH-carbon nanotube) produced well dispersed system and without agglomeration. Influences of carbon nanotube in bacterial cellulose were analyzed by FTIR. TGA showed higher thermal properties of developed bionanocomposites. Keywords: ∗ Author to whom correspondence should be addressed. J. Biomater. Tissue Eng. 2013, Vol. 3, No. 6 Transparent nanocomposites were fabricated by incorporating an aqueous silk fibroin solution into bacterial cellulose membranes. Another researches produced bacterial cellulose/carbon nanotubes by dipping in carbon nanotubes solution,13 by covalently bonded multiwalled carbon nanotube and cellulose14 and by changing bacterial cellulose culture medium with acid-treated multi-walled carbon nanotubes (MWNTs).15 However, poor dispersed system were produced. In theory, disease occurs in patients with inherited genetic predisposition or induced, which were exposed to secondary cofactors so a quickly detect with biocomposites are of great interest nowadays in academic and industrial sectors. In this scope a well dispersed conductive scaffolds with bacterial cellulose/carbon nanotube were produced by changing bacterial cellulose with polymer modified-carbon nanotube (PVOH-carbon nanotube). Influences of carbon nanotube in bacterial cellulose were analyzed by FTIR. TGA showed higher thermal properties of developed bionanocomposites. 2. MATERIALS AND METHODS 2.1. Materials Bacterial cellulose membranes were supplied from Innovatec’s—Produtos Biotecnológicos Ltda—Brazil. 2157-9083/2013/3/001/004 doi:10.1166/jbt.2013.1127 1 RESEARCH ARTICLE 1. INTRODUCTION Conductive nanomaterials are of great interest nowadays in academic and industrial sectors.1 Organic electronic devices have showed versatility in a wide range of applications including consumer electronics, photovoltaics and biotechnology.2 Of particular interest is the potential to fabricate biomaterials into the structural components for medicine devices.3 4 In this context, cellulose that is produced by bacteria has attracted researchers by changing structural features of microbial cellulose modifying its culture medium or surface modification by physical5–7 and chemical methods which have major applications in the medical area.8 9 However, bacterial cellulose has shown very promising characteristics for reinforcement material for composites with conductive properties.10 In this context, several papers has deal with preparation of bacterial cellulose-based conductive materials using carbon nanotube. Kim et al.11 obtained single-walled carbon nanotubes (SWCNTs)/bacterial composites embedding into a transparent polymer and Jung et al.12 produced electrically conductive transparent materials based on multiwalled carbon nanotubes (MWCNTs).
  • High Dispersivity Bacterial Cellulose/Carbon Nanotube Nanocomposite for Sensor Applications Carbon nanotube (MWCNT) powdered as produced cylinders and poly(vinyl alcohol—Mw ∼ 7,200—PVOH) were supplied from Sigma Aldrich. (a) 3. RESULTS AND DISCUSSION 3.1. SEM Images Bacterial cellulose/carbon nanotube were characterized by SEM. Figure 1 shows, as an example, SEM image of (a) bacterial cellulose formation and (b) bacterial cellulose/ carbon nanotubes. These results confirm that there were interaction between carbon nanotubes-PVOH and bacterial cellulose by changing bacterial cellulose culture medium.16 17 3.2. FTIR Influences of carbon nanotubes-PVOH in bacterial cellulose were analyzed in the range between 250 and 4000 cm−1 and with resolution of 2 cm−1 with FTIR analysis. The main features of the bacterial cellulose in infrared spectroscopy is: 3500 cm−1 : OH stretching, 2900 cm−1 : CH stretching of alkane and asymmetric CH2 stretching, 2700 cm−1 : CH2 symmetric stretching, 1640 cm−1 : OH deformation, 1400 cm−1 : CH2 2 (b) Fig. 1. (a) Bacterial cellulose; (b) Bacterial cellulose/carbon nanotube. deformation, 1370 cm−1 : CH3 deformation, 1340 cm−1 : OH deformation and 1320–1030 cm−1 : CO deformation.18 In Figure 2, it can be observed that in carbon nanotube/bacterial cellulose mats, it obtained changes in symmetrical stretching CH2 bonds of bacterial cellulose structures in 1640 cm−1 and another absorption peak was obtained in the range of 1490 cm−1 , which shows the presence of a carbonyl group in the bacterial cellulose together with bonds corresponding to those of glycoside, including C O C at 1162 cm−1 (as in case of natural cellulose).19 These results clearly shows one possible interaction between bacterial cellulose and carbon nanotubes-PVOH 80 70 Transmittance (a.u) RESEARCH ARTICLE 2.2. Methods 2.2.1. Synthesis and Fermentation of Bacterial Cellulose The acetic fermentation process is achieved by using the sugar as carbohydrate source. Results of this process would be vinegar and a nanobiocellulose biomass. The modified process is based on the addition of carbon nanotubes-PVOH (1% w/w) to the culture medium before bacteria are inoculated. After being added to the culture medium, the medium is autoclaved at 100 celsius degree. Then, bacterial Cellulose (BC) produced by Gram-negative bacteria Gluconacetobacter xylinus can be obtained from the culture medium in the pure 3-D structure consisting of an ultra fine network of cellulose nanofibers. 2.3. Characterization Scanning Electron Microscopy (SEM)—Scanning electronic microscopy images were performed on a PHILIPS XL30 FEG. The samples were covered with gold and silver paint for electrical contact and to perform the necessary images. Transmission infrared spectroscopy (FTIR, Perkin Elmer Spectrum 1000)—Influences of carbon nanotube on bacterial cellulose was analyzed in the range between 250 and 4000 cm−1 and with resolution of 2 cm−1 with samples. Thermo gravimetric analysis (TGA) was carried out for bionanocomposite using a NETZSCH TG 209F1. The samples were heated from 25 C to 800 C, at 10 degree/ min in inert (nitrogen) atmosphere. The weight of all specimens was maintained around 10 mg. Olyveira et al. 60 50 40 30 20 10 BC BC/carbon nanotubes 0 –10 4000 3500 3000 2500 2000 1500 1000 500 wavelength (nm) Fig. 2. FTIR spectra of bacterial cellulose/carbon nanotubes. J. Biomater. Tissue Eng. 3, 1–4, 2013
  • Olyveira et al. High Dispersivity Bacterial Cellulose/Carbon Nanotube Nanocomposite for Sensor Applications mainly by hydrogen interactions between hydroxyl and carbonyl groups. 100 bc Weight (%) 80 60 40 20 0 100 200 300 400 500 Temperature (Celsius) 1.6 1.4 DTG bc 3.3. TGA In order to analyze thermal behavior for bionanocomposites are characterized typical weight loss verses temperature plots. The TG spectrum (Fig. 3) shows a weak loss of weight due to the evaporation of water (at temp. 85 C) and also quick drop in weight at a temperature of approx. 300 C is mainly attributed to thermal depolymerization of hemicellulose and the cleavage of glycosidic linkages of cellulose,20 21 complete degradation of cellulose take place between 275 and 400 C.22 23 It can be observed that in comparison, bacterial cellulose and bacterial cellulose/carbon nanotubes, PVOH has its degradation at 225 C and carbon nanotube at 425 C.24 25 1.2 DTG 4. CONCLUSIONS 0.8 Bacterial cellulose with its characteristics like nanofibers size and distribution, mechanical properties, compatibility and ability to mold is a biomaterial indispensable in health area. It was the intention of this work to broaden knowledge in this subject area and stimulate the practical application of bacterial cellulose with new materials and biocomposites obtained with modified fermentation for potential applications for sensor applications and diseases diagnostic. In this scope a well dispersed conductive scaffolds with bacterial cellulose/carbon nanotube were produced by changing bacterial cellulose with polymer modified-carbon nanotube (PVOH-carbon nanotube). 0.6 0.4 0.2 0.0 0 100 200 300 400 500 Temperature (Celsius) 100 Bc/carbon nanotube Weight (%) 80 60 References and Notes 40 20 0 0 100 200 300 400 500 600 700 800 900 Temperature (Celsius) 1.2 DTGbc/carbon nanotube 1.0 DTG 0.8 0.6 0.4 0.2 0.0 0 100 200 300 400 500 600 700 800 900 Temperature (Celsius) Fig. 3. TGA thermogram of bacterial cellulose and bacterial cellulose/carbon nanotube. J. Biomater. Tissue Eng. 3, 1–4, 2013 1. S. H. Yoon, H. J. M. Jin, M. C. Kook, and Y. R. M. Pyun, Conductive bacterial cellulose by incorporation of carbon nanotubes. Biomacromolecules 7, 1280 (2006). 2. Z. Yan, S. Chen, H. Wang, B. Wang, C. Wang, and J. Jiang, Cellulose synthesized by Acetobacter xylinum in the presence of multiwalled carbon nanotubes. Carbohydr. Res. 343, 73 (2008). 3. G. M. Olyveira, G. A. X. Filho, L. M. M. Costa, C. R. Scher, L. X. Filho, P. Pranke, and P. Basmaji, Human dental pulp stem cell behavior using natural nanotolith/bacterial cellulose scaffolds for regenerative medicine. J. Biomedical Nanotechnology 9, 1 (2013). 4. L. X. Filho, G. M. Olyveira, L. M. M. Costa, and P. Basmaji, Novel electrospun nanotholits/PHB scaffolds for bone tissue regeneration. J. Nanosci. Nanotechnol. 13, 1 (2013). 5. G. M. Olyveira, L. M. M. Costa, and P. Basmaji, Physically modified bacterial cellulose as alternative routes for transdermal drug delivery. J. Biomater. Tissue Eng. 3, 1 (2013). 6. P. B. P. Gois, G. M. Olyveira, L. M. M. Costa, C. F. Chianca, I. I. S. Fraga, P. Basmaji, C. V. Cordoba, and L. X. Filho, Influence of symbioses culture between microorganisms/ yeast strain on cellulose synthesis. International Review of Biophysical Chemistry 3, 48 (2012). 7. L. M. M. Costa, G. M. Olyveira, P. Basmaji, and L. X. Filho, Nanopores structure in Electrospun Bacterial celulose. J. Biomaterials and Nanobiotechnology. 2, 92 (2012). 8. B. M. Cherian, G. M. Olyveira, L. M. M. Costa, A. L. Leão, and S. F. Souza, Protein Based Polymer Nanocomposites for Regenerative Medicine, Royal Society of Chemistry (RSC Green 3 RESEARCH ARTICLE 1.0
  • High Dispersivity Bacterial Cellulose/Carbon Nanotube Nanocomposite for Sensor Applications 9. 10. 11. 12. 13. 14. 15. 16. 17. Chemistry), No. 17, edited by John J. Maya and S. Thomas, Natural Polymers, Nanocomposites (2012), Vol. 2, pp. 255–293. D. P. Valido, L. M. M. Costa, G. M. Olyveira, P. B. P.Góis, R. L. A. C. Júnior, L. X. Filho, and P. Basmaji, Novel otholits/bacterial celulose nanocomposites as a potential natural product for direct dental pulp capping. J. Biomater. Tissue Eng. 2, 48 (2012). P. Basmaji, G. M. Olyveira, L. M. M. Costa, and L. X. Filho, Bacterial nanocellulose for medicine regenerative. J. Nanotech. Eng. Med. 2, 034001 (2011). Y. Kim, H. S. Kim, H. Bak, Y. S. Yun, S. Y. Cho, and H. J. Jin, Transparent conducting films based on nanofibrous polymeric membranes and single-walled carbon nanotubes. J. Appl. Polym. Sci. 114, 2864 (2009). R. Jung, H. S. Kim, Y. Kim, S. M. Kwon, H. S. Lee, and H. J. Jin, Electrically conductive transparent papers using multiwalled carbon nanotubes. J. Polym. Sci., Part B: Polym. Phys. 46, 1235 (2008). T. Tanaka, E. Sano, M. Imai, and K. Akiyama, Electrical conductivity of carbon-nanotube/cellulose composite paper. J. Applied Physics 107, 054307 (2010). S. Yun, S. D. J. Ang, G. Y. Yun, J. H. Kim, and J. Kim, Paper transistor made with covalently bonded multiwalled carbono nanotube and celulose. Appl. Phys. Lett. 95, 104102 (2009). P. Chen, S. Y. Cho, and H. J. Jin, Modification and applications of bacterial celluloses in polymer science. Macromolecular Research 18, 309 (2010). L. M. M. Costa, G. M. Olyveira, P. Basmaji, and L. X. Filho, Bacterial cellulose towards functional medical materials. J. Biomater. Tissue Eng. 2, 185 (2012). G. M. Olyveira, L. M. M. Costa, P. B. P. Góis, P. Basmaji, and L. X. Filho, Novel natural transdermal patch for osteoporosis treatment. J. Nanotech. Eng. Med. 2, 031011 (2011). Olyveira et al. 18. R. G. Zhbanko, Infrared Spectra of Cellulose and Its Derivates, Translated from the Russian by A. B. Densham, edited by B. I. Stepanov, Consultants Bureau, New York (1966), pp. 325–333. 19. L. M. M. Costa, G. M. Olyveira, P. Basmaji, and L. X. Filho, Bacterial cellulose towards functional green composites materials. J. Bionanoscience 5, 167 (2011). 20. B. L. Manfredi, E. S. Rodriguez, M. Wladyka-Przybylak, and A. Vazquez, Thermal degradation and fire resistance of unsaturated polyester modified acrylic resins and their composites with natural fibers. Polym. Degrad. Stab. 91, 255 (2006). 21. S. Ouajai and R. A. Shanks, Composition, structure and thermal degradation of hemp cellulose after chemical treatments. Polym. Degrad. Stab. 89, 327 (2005). 22. V. A. Alvarez and A. Vazquez, Thermal degradation of cellulose derivatives/starch blends and sisal fiber biocomposites. Polym. Degrad. Stab. 84, 13 (2004). 23. B. M. Cherian, A. L. Leão, S. F. Souza, G. M. Olyveira, L. M. M. Costa, C. V. S. Brandão, and S. S. Narine, Bacterial nanocellulose for medical implants, Advances in Natural Polymers, Advanced Structured Materials, edited by S. Thomas, P. M. Visakh, and A. P. Mathew, Springer Berlin Heidelberg (2013), Vol. 18, pp. 337–359. 24. G. M. Olyveira, D. P. Valido, L. M. M. Costa, P. B. P. Gois, L. X. Filho, and P. Basmaji, First otoliths/collagen/bacterial cellulose nanocomposites as a potential scaffold for bone tissue regeneration. J. Biomaterials Nanobiotechnology 2, 239 (2011). 25. P. Basmaji, G. M. Olyveira, and L. M. M. Costa, Nanoskin for medical application. Proceeding of Nanotechnology 2011, Bio Sensors, Instruments, Medical, Environment and Energy, Boston, USA, June (2011). RESEARCH ARTICLE Received: XX Xxxxx XXXX. Accepted: XX Xxxxx XXXX. 4 J. Biomater. Tissue Eng. 3, 1–4, 2013