Thesis (M.Ch.E.)--University of Delaware, 2008. / Principal faculty advisor: Richard P. Wool, Dept. of Chemical Engineering. Includes bibliographical references.

Ο σκοπός της παρούσας διπλωματικής εργασίας ήταν η δημιουργία ενός νανοσύνθετου υλικού με αυξημένες μηχανικές ιδιότητες και βιοσυμβατότητα. Η χιτοζάνη είναι ένας γραμμικός πολυσακχαρίτης και είναι παράγωγο της χιτίνης. Είναι ιδιαίτερα βιοσυμβατή και βιοδιασπώμενη, μπορεί να πραγματοποιήσει αδιάλυτες ενώσεις και μπορεί εύκολα να χρησιμοποιηθεί σε ογκώδη, πορώδη ικριώματα και φιλμς, Έχει ευρεία χρήση σε βιοφαρμακευτικές εφαρμογές σε τομείς όπως η μηχανική ιστών, τα φάρμακα, η θεραπεία πληγών και τα υποκατάστατα οστών. Μελέτες που προηγήθηκαν έδειξαν πως η χιτοζάνη αυξάνει τον αριθμό των κυττάρων που έχουν προσκολληθεί σε σύγκριση με τις επιφάνειες ελέγχου. Οι νανοσωλήνες άνθρακα αποτελούνται από άτομα άνθρακα με κατάλληλους δεσμούς μεταξύ τους ώστε να σχηματίζουν έναν κυλινδρικό σωλήνα του οποίου το μήκος είναι πολλές τάξεις μεγέθους μεγαλύτερο από τη διάμετρο του, περίπου 103 με 104. Οι νανοσωλήνες άνθρακα διακρίνονται σε μονού και πολλαπλού τοιχώματος. Οι πολλαπλού τοιχώματος αποτελούνται από πολλές στρώσεις ομόκεντρων νανοσωλήνων άνθρακα ενώ οι μονού, από μία. Οι νανοσωλήνες άνθρακα έχουν εξαιρετικές μηχανικές ιδιότητες, όπως εφελκυστική αντοχή μερικά GPa και μέτρο ελαστικότητας μερικά TPa, και, σαν έγκλεισμα, βελτιώνουν τις μηχανικές ιδιότητες της μήτρας, δίνοντας ένα νανοσύνθετο υλικό με πολύ καλύτερες μηχανικές ιδιότητες από αυτές που έχει το υλικό της μήτρας. Λαμβάνοντας υπ’ όψη τα δύο παραπάνω, παρασκευάστηκαν φιλμς από χιτοζάνη (CS) και δύο ειδών φιλμς από χιτοζάνη με διαφορετικές περιεκτικότητες σε νανοσωλήνες άνθρακα 0,001% w/v και 0,002% w/v (CS-CNTs). Κατόπιν κόπηκαν κατάλληλα δοκίμια CS και CS-CNTs καταπονήθηκαν σε εφελκυσμό. Η εφελκυστική μηχανή που χρησιμοποιήθηκε ήταν ο μικρογραφικός ελεγκτής υλικών MiniMat 2000. Τα προς εξέταση δείγματα που εφελκύστηκαν ήταν: CS, CS-CNTs 0,001% w/v, CS-CNTs 0,002% w/v. Τα πειράματα επαναλήφθηκαν περίπου 15 φορές για κάθε περίπτωση και με χρήση του MiniMat2000 προέκυψαν οι γραφικές παραστάσεις τάσης – παραμόρφωσης και με τους κατάλληλους υπολογισμούς βρέθηκε το μέτρο ελαστικότητας κάθε υλικού. Μετά τα πειράματα της μηχανικής καταπόνησης παρατηρήθηκε ότι το μέτρο ελαστικότητας του CS-CNTs 0,001% w/v εμφάνισε αύξηση της τάξεως 44% σε σύγκριση με το μέτρο ελαστικότητας της CS ενώ του CS-CNTs 0,002% w/v εμφάνισε αύξηση της τάξεως 36%. Από αυτό συμπεραίνουμε πως θα υπάρχει μια μέση τιμή πρόσμιξης CNTs για την οποία μεγιστοποιείται το μέτρο ελαστικότητας. Περαιτέρω πειράματα κρίνονται αναγκαία για την μελέτη του υλικού. Ο έλεγχος της βιοσυμβατότητας των υλικών CS-CNTs και MWCNTs έγινε με καλλιέργεια πρόβειων μυοϊνοβλαστικών κυττάρων. Τα πειράματα που πραγματοποιήθηκαν ήταν ο έλεγχος της κυτταροτοξικότητας, του πολλαπλασιασμού και της απόπτωσης για μυοϊνοβλαστικά κύτταρα, τα οποία εξετάστηκαν για 1, 3 και 8 ημέρες. Τα αποτελέσματα του ελέγχου της κυτταροτοξικότητας έδειξαν ότι και τα δυο MWCNTs και CS-CNTs παρήγαγαν πολύ χαμηλό επίπεδο τοξικότητας. Τα αποτελέσματα του πειράματος του πολλαπλασιασμού έδειξαν ότι στην περίπτωση των μυοϊνοβλαστικών κυττάρων υπήρξε αύξηση του πολλαπλασιασμού μετά από 8 ημέρες κυτταροκαλλιέργειας και για τα MWCNTs και τη CS-CNTs. Η μεγαλύτερη αύξηση παρατηρήθηκε στη CS-CNTs. Επιπλέον, δεν υπήρξε απόπτωση σε καμία επιφάνεια, όσο και για τα MWCNTs και για τη CS-CNTs. Συνοψίζοντας, καταλήγουμε ότι οι νανοσωλήνες άνθρακα αυξάνουν τις μηχανικές ιδιότητες του νανοσύνθετου υλικού CS-CNTs, δεν επηρεάζουν αξιοσημείωτα την κυτταροτοξικότητα, δεν δημιουργούν απόπτωση και αυξάνουν τον πολλαπλασιασμό των πρόβειων μυοϊνοβλαστικών κυττάτων. / The aim of this thesis was to create a nanocomposite material with increased mechanical properties and biocompatibility. Chitosan is a linear polysaccharide and is a derivative of chitin. It is highly biocompatible and biodegradable, can form ​​insoluble compounds and can easily be used in massive, porous scaffolds and films. It has been widely used in biomedical applications in areas such as tissue engineering, pharmaceuticals, wound healing and bone substitutes. Prior studies have shown that chitosan increases the number of adherent cells compared with control surfaces. Carbon nanotubes (CNTs) consist of carbon atoms with appropriate links between them to form a cylindrical tube whose length is several orders of magnitude larger than the diameter of around 103 to 104. CNTs can be either into single or multi walled. The multi-walled CNTs are composed of several concentric layers of carbon nanotubes while the single, one layer. CNTs have excellent mechanical properties such as tensile strength of the order of several GPa and young modulus of the order of TPa, and, as a filler improves the mechanical properties of the matrix, resulting in a nanocomposite material with much better mechanical properties than those of the material matrix. Taking into account the two above films prepared from chitosan (CS) and two types of chitosan films with different contents of carbon nanotubes 0,001% w / v and 0,002% w / v (CS-CNTs) were and the results were compared. A mold was designed and built in AutoCAD for the preparation of the into a suitable shape.The mechanical tests were performed with a tensile machine the miniature materials tester MiniMat 2000. The samples that were tested were: CS, CS-CNTs 0,001% w / v, CS-CNTs 0,002% w / v. The experiments were repeated about 15 times for each case and using the resulting MiniMat2000 graphs stress - strain and the young's modulus of each material was calculated. The results showed that the young's modulus of CS-CNTs 0,001% w / v was increased at 44% compared to the tensile modulus of the CS and that of CS-CNTs 0,002% w / v was increased at 36% . This suggests that there will be an optimum content of CNTs for which the young's modulus is maximized. Further experiments are necessary to study the material. Myofibroblasts were used, in order to evaluate the biocompatibility of the materials CS-CNTs and MWCNTs. In particular cytotoxicity, proliferation and apoptosis of cells, were evaluated after for 1, 3 and 8 days of culture. Test results showed that both MWCNTs and CS-CNTs produced very low toxicity myofibroblasts. The proliferation of Myofibroblasts in the case of cell proliferation was increased after 8 days of cell culture both on MWCNTs and on CS-CNTs. The largest increase was observed on CS-CNTs. Moreover, there was no apoptosis on any of the surfaces, MWCNTs or CS-CNTs. In summary, we conclude that carbon nanotubes enhance the mechanical properties of the nanocomposite material CS-CNTs, are not cytoxic, do not generate apoptosis and increase the proliferation of sheep Myofibroblasts cells.

Made available in DSpace on 2014-06-11T19:27:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-07-06Bitstream added on 2014-06-13T18:31:00Z : No. of bitstreams: 1 pereira_ac_me_guara.pdf: 1301531 bytes, checksum: bc9fd4753c17ea915b6f6ca3419e26a1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As resinas polibenzoxazinas constituem uma nova classe de resinas fenólicas termorrígidas que surgiram nas últimas décadas, superando as propriedades das tradicionais resinas epóxi e fenólicas aplicadas na indústria aeroespacial. A incorporação de baixa concentração em massa de nanotubo de carbono (NTC) em matrizes poliméricas pode produzir materiais estruturais com propriedades superiores. Nesse sentido, o presente trabalho tem como objetivo a preparação de compósitos nanoestruturados de resina benzoxazina/NTC, bem como o estudo da cinética de cura da resina benzoxazina e de seus compósitos nanoestruturados. Além disso, objetiva-se, ainda, a caracterização térmica da resina benzoxazina curada e de seus compósitos nanoestruturados também curados pelo mesmo ciclo de cura. O estudo da cinética de cura foi realizado por meio da técnica de calorimetria exploratória diferencial (DSC) sob condições não-isotérmicas (dinâmicas). A caracterização térmica foi realizada por meio do uso de termogravimetria, da análise dinâmico-mecânica, da análise termomecânica, do DSC e por análises de espectroscopia de infravermelho com transformada de Fourier e microscopia eletrônica de varredura. A partir destas análises, concluiu-se, de maneira geral, que os nanotubos de carbono agem como catalisadores da cura da matriz de benzoxazina sem afetar suas temperaturas iniciais e finais de polimerização. A adição de NTC não modifica a estabilidade térmica da resina benzoxazina e nem a temperatura de transição vítrea (Tg) dos compósitos nanoestruturados, com exceção da adição de 0,1% em massa de NTC na matriz polimérica que gera um aumento na Tg / Polibenzoxazine resins are a new class of thermosetting phenolic resins that have emerged in recent decades, overcoming the traditional properties of epoxy and phenolic resins applied in the aerospace industry. The addition of small amount of carbon nanotube in polymeric matrices can produce superior structural materials. Thus, this work aims to prepare nanostructured composite benzoxazine resin/NTC as well the study of the cure kinetic of neat benzoxazine resin and their nanostructured composites produced. Moreover, the objective is also the thermal characterization of cured neat benzoxazine resin and their composites nanostructured also cured by the same cure cycle. The study of cure kinetics was performed using the technique of differential scanning calorimetry (DSC) under non-isothermal (dynamic). The thermal characterization was performed by using thermogravimetry, dynamic mechanical analysis, thermomechanical analysis, DSC analysis and infrared spectroscopy with Fourier transformed and scanning electron microscopy. From these tests, it can be concluded, in general, that the carbon nanotubes act as catalysts for curing the benzoxazine matrix without affecting the initial and final temperatures of polymerization. The addition of CNT does not change neither the thermal stability of the benzoxazine resin nor the glass transition temperature (Tg) of nanostructured composites, except for the addition of 0.1 wt% of CNT in polymer matrix that generates a slight increase in Tg

Fiber and matrix-dominant properties of fiber-reinforced polymer composites are important in many advanced technological fields, such as aviation, aerospace, transportation, energy industry, etc. Still, pre-mixing the polymer matrix with nanoparticles may enhance the through-thickness or matrix-dominant properties, and surface treatment of fiber reinforcements with nanoparticles, on the other hand, may improve the in-plane or fiber-dominated properties of laminated composites, as well as interfacial adhesion. A novel manufacturing method that combines a spraying process with nanoparticle/epoxy mixture technique was introduced to incorporate carbon nanoparticles for enhancement of thermal properties of multiscale laminates. Several graphene-based nanomaterials including graphene oxide (GO), reduced graphene oxide (rGO), graphene nanoplatelets (GNPs) and multi-walled carbon nanotubes (MWCNTs) were employed to modify the epoxy matrix and the surface of glass fibers. Multiscale glass fiber-reinforced composites were fabricated from unmodified and modified epoxy, as well as fibers, using the vacuum-assisted resin transfer molding (VARTM) process. The composites obtained combined improvements in both the fiber and matrix- dominant properties, resulting in superior composites. The morphological, rheological, thermal and mechanical properties of the glass fiber-reinforced multiscale composites were investigated. The thermal properties of the epoxy/nanoparticle composites were studied through differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and thermal conductivity measurements. The tensile, bending, vibration, interlaminar shear strength (ILSS) and thermal characterization results indicated that the introduction of GNPs, GO, rGO, and MWCNTs enhanced the themo-mechanical properties. The fracture surfaces of the fiber-reinforced composites were examined by scanning electron microscopy (SEM) and the micrographs were analyzed to comment on the mechanical results.

The focus of this research was to investigate the role of carbon nanotubes as active catalysts in the Fischer-Tropsch reaction to derive liquid fuels from synthesis gas. Carbon nanotubes (CNTs) have unique structural and mechanical properties that make them ideal catalyst supports, but they also exhibit catalytic potential as well. This study implored the use of multi-walled CNTs on different substrates and single-walled CNTs grown from various precursors to analyze the effectiveness of the CNTs in FT synthesis. Multi-walled nanotubes (MWNTs) were tested on two different substrates: alumina pellets and inconel. The MWNTs on the alumina substrate yielded nearly all alkane and alkene products, with very little aromatic products. The amount of converted syngas reached 97% but had a high liquid product selectivity to methane, at roughly 57%. The MWNTs on inconel substrate produced nearly 80% aromatic products in one stage of the experiment, while the other three stages produces almost all alkane products with little oxygenates. Much of the liquid product yield (upwards of 73%) was between C10 and C21, which is ideal for diesel fuel. Single-walled nanotubes (SWNTs) were also tested in the FTS. All of the SWNTs were tested under a series of 6 temperatures, 300psig, and a syngas ratio of 1:1. Iron, nickel, and cobalt, which have all been proven as effective FT catalysts, were tested in trace amounts with CNTs. Fe-SWNTs (ferrocene assisted SWNTs) yielded a product of 100% C7 and C8 carbon species at two of the temperatures while 3 of the temperatures held a combination of longer chained alkanes, of C18 and longer. However, the last temperature converted 100% of the feedgas into methane and CO2. The product selectivity to CH4 and CO2 posed a problem with the Fe-SWNTs catalyst, where in all temperatures the selectivity exceeded 80%. Ni-SWNTs (nickellocene assisted SWNTs) yielded slightly better results with a higher selectivity to C2-C7, but no selectivity to longer chained hydrocarbons. Co-SWNTs (cobaltocene assisted SWNTs) tested under the same parameters yielded similar results as the Fe-SWNTs, with a very high selectivity to CH4 and CO2. Only at temperatures of 300 and 250°C were there any selectivity to compounds other than CH4 and CO2, but less than 10% selectivity to those alkanes (C2+). The final experiment consisted of a catalyst prepared from a feed solution containing a mixture of ferrocene and nickellocene. The Fe+Ni-SWNT catalyst underwent the same conditions as the other SWNT catalysts, this combination yielded favorable results with over 98% conversion of syngas over all temperatures and a high selectivity to shorter chain length hydrocarbons, namely alkanes of chain lengths between C2 and C7. Although the higher temperatures did show a selectivity to methane (roughly 45%), the CO2 selectivity was rather low, below 10% (except at 450°C, which pushed 20%).

Carbon nanotube bundles hold great promise for adsorption applications. However, most of the work done thus far has focused on the equilibrium properties of adsorption; the kinetics of adsorption is still not well understood. There also exist large discrepancies in the reported uptake of particles in the internal adsorption sites of carbon nanotube bundles. The purpose of this project was to elucidate the kinetics of adsorption in carbon nanotube bundles and to determine what kinetic factors, if any, may have caused the variations in experimental results. We studied the adsorption of particles in carbon nanotube bundles using analytical and computational techniques. By employing these separate but parallel methods, we were able to constantly compare and verify our results. We calculated and simulated the behavior of the system throughout its evolution and then analyzed our results to determine which system parameters had the greatest effect on the kinetics of adsorption. Our analytical and computational results showed good agreement with each other and with the experimental isotherm data provided by our collaborators. As a result of this project, we now know that the equilibration time of a system depends primarily on the binding energy of the adsorbates and the temperature. Specifically, the highest adsorption rates and shortest equilibration times are observed in systems with low binding energies and high temperatures. We also discovered that equilibration time for internal adsorption phases can be several orders of magnitude larger than those for external phases, which may have led to the disagreements in reported experimental results. Because of this work, we now better understand the process of equilibration.

The thesis describes a study of the modifications of orthopaedic Ti-based substrates using nanomaterials, and the evaluation of their biocompatibility for further use as implant material, with the aim to develop new, biocompatible β-Ti/CNT composite materials. Traditionally, CNTs require the presence of a transition metal catalyst such as Fe, Ni, Co, for successful growth. Different aspects of a catalyst-assisted CVD MWCNTs growth on various Ti-based substrates including bulk, thin films and 3D porous scaffolds, have been investigated. Low concentrations of catalyst were deposited using spin coating on titanium substrates of various forms and shapes. A strong influence of the surface topography was observed. In contrast, no effect of the elemental composition of the substrate could be detected. To evaluate the biocompatibility of the newly created materials, cell culture studies using fetal human osteoblasts (fHobs) were performed. It was shown that β-Ti/MWCNTs samples possess good initial osteoblast attachment, but no long-term osteoblast activity. Hence the biocompatibility of isolated (i.e. without a Ti substrate) MWCNTs was studied, using MWCNT carpets and various types of MWCNTs buckypapers. All the samples revealed very low cell activity. While β-Ti/MWCNTs samples did not exhibit good biocompatibility, alternative β-Ti/TiC samples were synthesized with a simple CVD method and revealed good osteoblast response with increased mineralization. Moreover, good corrosion resistance and mechanical properties of β-Ti/TiC samples have been reported. Finally, successful method for non-catalytic CVD MWCNTs growth on Ti substrates was developed for the first time, thereby excluding potentially toxic catalysts from the implant material. CVD was performed with acetylene precursor on bulk titanium substrates etched with Piranha solution, which generated an appropriate surface to foster MWCNTs growth. A combination of the change in the surface roughness, improved hydrophilicity, and elemental composition of the surface as a result of the Piranha etching is likely to be responsible for the successful formation of MWCNTs.

Structured electrodes with tailored nanoscale morphology and chemistry are highly desirable for a range of applications. In particular, emerging energy storage applications such as thick Lithium-ion battery (LIB) electrodes and photoanodes for watersplitting require new electrode structures that simultaneously optimise electron, ion, and thermal transport. In this PhD thesis, advanced structured electrodes are fabricated by creating 3D carbon-inorganic hybrid architectures. In this process, patterned vertically aligned carbon nanotubes (CNT) were used as the structural scaffolds to shape the electrodes while inheriting the excellent thermal and electrical properties of CNTs. First, UV and colloidal lithographic patterning processes were developed to create micro- and nanopores respectively within the CNT structures. Those structures provide high surface area and conductive backbone for the synthesis of hybrid CNT-inorganic structures. Specifically, the parameter space to create honeycomb shaped CNT structures with pores ranging from 300~nm to 30~$\mu$m has been established. Next, the micro-pore CNT structures have been chemically modified with iron oxide using microwave-assisted, hydrothermal synthesis for fabricating high areal loading LIB anodes. The areal loading was increased by 120\% compared to a standard battery film while at the same time retaining a high capacity (900 mAhg$^{-1}$ at 0.2 C). Then thick electrodes with optimised diffusion pathways were created by coating the nanopatterned CNTs with silicon using physical vapour deposition. These electrode structures are up to 50\% thicker than previously reported structures and still retain a stable capacity (650 mAhg$^{-1}$) and a good high-rate performance. Finally, the honeycomb shaped CNT structures have been coated with bismuth vanadate using a hotcasting process and the electrode architecture has been optimized for good conductivity by the addition of a Pd/Au layer between the CNTs and the BiVO$_{4}$. The photoelectrode performance was measured and shows a clear increase in current density when exposed to light. Each of these novel electrodes illustrate how patterning vertically aligned carbon nanotube structures combined with inorganic surface modification enables the creation of advanced electrodes with new formfactors and improved performance in comparison to literature and to classic drop-casted battery films of the same materials.

Graphene is essentially a monolayer of sp2 bonded carbon atoms, arranged in a honeycomb lattice. Graphene has in recent years attracted phenomenal interest from researchers in materials science, condensed matter physics, and electronics since its first demonstration in 2004. The importance of graphene research was epitomised by the Nobel prize for physics being awarded to pioneers of the field in 2010. The main topic of this research was the development of epitaxial graphene on silicon carbide (SiC) substrates. The substrate inferred processability of epitaxial graphene enables graphene devices to be fabricated on full wafers using standard semiconductor processing techniques. Biosensor research is a rapidly expanding field. The major driver comes from the healthcare industry but there are also applications for biosensors in the food quality appraisal and environmental monitoring industries. The key advantages of electrochemical biosensors over competing sensor technologies are the low cost of mass production, and ability to make sensors into small compact systems. Smaller, portable sensors allow for the development of point-ofcare medical devices, which can be crucial in fast diagnosis and long-term monitoring of diseases. Graphene channel resistor devices have been fabricated using electron beam lithography and a successfully developed contact metallisation scheme - using Titanium / Gold contacts. The metal-graphene contacts have been characterised using XPS and electrical current-voltage measurements. The graphene channel device has been used as the basis of an electrochemical sensor for human chorionic gonadotropin (hCG), an indicator of pregnancy - which has also been linked to increased risk of several cancers. The immunosensor developed is a promising tool for point-of-care detection of hCG, due to its excellent detection capability, simplicity of fabrication, low-cost, high sensitivity and selectivity.

Resumo: As resinas polibenzoxazinas constituem uma nova classe de resinas fenólicas termorrígidas que surgiram nas últimas décadas, superando as propriedades das tradicionais resinas epóxi e fenólicas aplicadas na indústria aeroespacial. A incorporação de baixa concentração em massa de nanotubo de carbono (NTC) em matrizes poliméricas pode produzir materiais estruturais com propriedades superiores. Nesse sentido, o presente trabalho tem como objetivo a preparação de compósitos nanoestruturados de resina benzoxazina/NTC, bem como o estudo da cinética de cura da resina benzoxazina e de seus compósitos nanoestruturados. Além disso, objetiva-se, ainda, a caracterização térmica da resina benzoxazina curada e de seus compósitos nanoestruturados também curados pelo mesmo ciclo de cura. O estudo da cinética de cura foi realizado por meio da técnica de calorimetria exploratória diferencial (DSC) sob condições não-isotérmicas (dinâmicas). A caracterização térmica foi realizada por meio do uso de termogravimetria, da análise dinâmico-mecânica, da análise termomecânica, do DSC e por análises de espectroscopia de infravermelho com transformada de Fourier e microscopia eletrônica de varredura. A partir destas análises, concluiu-se, de maneira geral, que os nanotubos de carbono agem como catalisadores da cura da matriz de benzoxazina sem afetar suas temperaturas iniciais e finais de polimerização. A adição de NTC não modifica a estabilidade térmica da resina benzoxazina e nem a temperatura de transição vítrea (Tg) dos compósitos nanoestruturados, com exceção da adição de 0,1% em massa de NTC na matriz polimérica que gera um aumento na Tg / Abstract: Polibenzoxazine resins are a new class of thermosetting phenolic resins that have emerged in recent decades, overcoming the traditional properties of epoxy and phenolic resins applied in the aerospace industry. The addition of small amount of carbon nanotube in polymeric matrices can produce superior structural materials. Thus, this work aims to prepare nanostructured composite benzoxazine resin/NTC as well the study of the cure kinetic of neat benzoxazine resin and their nanostructured composites produced. Moreover, the objective is also the thermal characterization of cured neat benzoxazine resin and their composites nanostructured also cured by the same cure cycle. The study of cure kinetics was performed using the technique of differential scanning calorimetry (DSC) under non-isothermal (dynamic). The thermal characterization was performed by using thermogravimetry, dynamic mechanical analysis, thermomechanical analysis, DSC analysis and infrared spectroscopy with Fourier transformed and scanning electron microscopy. From these tests, it can be concluded, in general, that the carbon nanotubes act as catalysts for curing the benzoxazine matrix without affecting the initial and final temperatures of polymerization. The addition of CNT does not change neither the thermal stability of the benzoxazine resin nor the glass transition temperature (Tg) of nanostructured composites, except for the addition of 0.1 wt% of CNT in polymer matrix that generates a slight increase in Tg / Orientador: Michelle Leali Costa / Coorientador: Edson Cocchieri Botelho / Banca: Mirabel Cerqueira Rezende / Banca: José Maria Fernandes Marlet / Mestre