La unión de las propiedades de los CNT con los principios de reconocimiento molecular se presenta como una base adecuada para el desarrollo de sensores altamente específicos. El objetivo de la presente tesis ha sido desarrollar sensores químicos, del tipo transistores de efecto campo (CNTFET), basados en interacciones receptor-analito, mediante el empleo de los nanotubos de pared sencilla (SWCNT), que actúan como transductores de la señal analítica.Las principales etapas de la parte experimental han sido: Crecimiento de SWCNT con la técnica de deposición química en fase vapor. Integración de los SWCNTs en sistemas CNTFET. Empleo del CNTFET como base del sensor en distintos campos utilizando modelos de reconocimiento molecular. Dependiendo del tipo de funcionalización de los SWCNTs se pueden obtener sensores para proteínas, iones, etc. Como resultado, se han desarrollado y estudiado sensores basados en CNTFETs para la detección distintos analitos de interés, como son la Inmunoglobulina G Humana, los iones potasio y el dióxido de azufre. / The general objective of this thesis is to develop chemical sensors whose sensing capacities are based on the principle of molecular recognition and where the transduction is carried out by single-walled carbon nanotubes (SWCNT).The sensing device used is the carbon nanotube field-effect transistor (CNTFET). The new structure of the CNTFET allows nanotubes to be integrated at the surface of the devices, thus exploiting SWCNTs' sensitivity to changes in their environment. The functionalization of SWCNTs with several types of molecular receptors such as antibodies, ion selective membranes, and synthetic receptors, achieve a high selectivity towards the analyte of interest. This thesis shows that CNTFETs can be used for the successful selective detection of different types of target analytes. These can be biomolecules such as antigens, small compounds such as cations or gas-phase compounds such as SO2.

No description available.

No description available.

Field emission cathodes have proven themselves to be excellent candidates for some special medical X-ray applications. Spindt cathode and CNT (carbon nanotube) based field emission cathode have been widely studied for many years. Spindt cathode has the near perfect structure, but the material property limits its applications. On the other hand, low density vertically aligned CNT array has been proved the best candidate of field emission material. Several attempts have been made to combine the advantages of the Spindt cathode and CNT array, but some most important advantages of Spindt cathode have not been successfully utilized in CNT emitter design, for example: ballast resistor, self-aligned fabrication process, sub-micron scale gate electrode, and low control voltage. In this thesis, the design, fabrication and test of CNT based field emission cathode with a novel ballast resistor and coaxial cylinder shape gate electrode is reported. A connection pad has been reported for the first time. This structure makes the ballast resistor can be utilized in a CNT field emitter array. Therefore, the uniformity and stability of field emission current is improved significantly. In addition, the stabilized emission current heated up the sample to a high temperature and changes the emission from field emission to Schottky emission regime. This is the first report of the self-heating Schottky emission from a CNT emitter array. Coaxial cylinder shape gate electrode is another important improvement in the CNT emitter design. The gate electrode adopts the self-alignment property of the Spindt cathode, and adjusted to fit the structure and synthesis process of CNT array. This new design and fabrication process has all the advantages of both the Spindt cathode and CNT emitter. In addition to the field emission cathode design, a novel PMMA (poly methyl methacrylate) based FEM (field emission microscope) is designed to evaluate the emission uniformity and capture high resolution images of the distribution of field emitted electrons. Compare to the conventional phosphor screen based FEM, the PMMA based FEM has a much higher resolution and sensitivity. Images of this new FEM have a resolution of as high as 0.34 nm and clearly show the boundary of crystal facets.

Three dimensional (3D) hybrid architectures are new types of materials that have a number of technological applications. However, the synthesis of such materials has been problematic to date. The objective of this study is to fabricate 3D hybrid architectures composed of sp2-carbon nanomaterials and inorganic nanostructures using a convenient microwave assisted technique. Sp2-Carbon nanomaterials such as carbon nanotubes (CNTs), graphene and its derivative graphene oxide (GO), have been explored by researchers as major components of hybrid materials due to their exceptional electrical, thermal, mechanical and biological properties. However, most of the research has been devoted to the hybrids with randomly dispersed phases. The present study explores the feasibility of using aligned 3D sp2-carbon structures in a bottom-up microwave-assisted chemical synthesis approach to fabricate various 3D sp2-carbon/inorganic hybrid architectures. The carbon nanostructures, either tubular or planar, not only contribute to the functionalities of the hybrids, but also template the ordered assembly of phases on nanometer scale. Mimicking nature is a key to develop novel types of materials with enhanced physical and mechanical properties suitable for advanced applications (e.g. lightweight and yet tough materials that are extensively needed in automotive and aerospace industries). One approach to obtain such materials or devices is to mimic nature processes and synthesize hybrid materials with ordered structures on the nanometer scale. Those functional structures are fabricated in this thesis through an in-situ microwave synthesis of inorganic materials on 3D sp2-carbon architectures. Generally, in chapter 1, it was shown and discussed the procedures to fabricate 3D architectures of carbon nanotubes and graphene oxide as basic components for template synthesis of the hybrids. Then in chapter 2 the microwave chemical synthesis approach was introduced as a convenient route for fabricating inorganic materials such as zinc oxide (ZnO) which was shown to be used as UV sensors. Through photolithography patterning of the iron catalyst thin films on Si/SiO2 substrates, 3D aligned CNT structures were fabricated and were coated in-situ with inorganic materials such as cobalt oxide, zinc oxide and manganese oxide using a microwave synthesis approach (chapter 3). The obtained aligned strips of CNT/Co3O4 were chosen as an example to illustrate the application of such 3D hybrids in energy storage applications. The capacitance of the aligned CNT/Co3O4 strips was measured to be 123.94 F/g. Using graphene oxide as template for manufacturing the 3D sp2-carbon/inorganic hybrid structures, interesting novel layered configurations are obtained that are similar to the layered structures of exoskeleton of the mollusks nacre. The layered hybrid structure shown to be mechanically improved compared to its constituents (chapter 4). Finally in chapter 5, some of the future routes have been proposed for further research on this novel field of 3D hybrid materials composed of sp2-carbons and inorganic nanomaterials.

Carbon nanotubes (CNT) and graphene have been one of the noticeable research areas in science and technology. In recent years, the assembly of these carbon nanostructures is one of the most interesting topic to the scientific world due to its variety of applications from nano to macroscale. These bulk nanostructures to be applicable in shock absorbers, batteries, sensors, photodetectors, actuators, solar cells, fuel cells etc. The present work is motivated to study the detailed compressive behavior of three dimensional cellular assemblies of CNT and graphene. The CNT foams are synthesized by chemical vapor deposition method. It is interesting to study the compressive behavior of CNT foam in the presence external magnetic field applied perpendicular to CNT axis. The peak stress and energy absorption capability of CNT foam enhances by four and nearly two times in the presence of magnetic field as compared to the absence of the magnetic field. In the absence of magnetic field the deformation of CNT foam is obtained elastic, plateau and densification regions. Further CNT foam is loaded with iron oxide nanoparticles of diameter is ~ 40nm on the surface and detailed study of the compressive behavior of the foam by varying iron nanoparticles concentration. The peak stress and energy absorption capability of CNT foam initially decreases with increasing the intensity of the magnetic field, further increases the intensity of the magnetic field the maximum stress and energy absorption capability increases which is due to magnetic CNT and particles align in the direction of the magnetic field. CNT surfaces were further modified by fluid of different viscosities. The mechanical behavior of CNT foam filled with fluids of varying viscosities like 100%, 95% and 90% glycerol and silicone oil are 612, 237, 109 and 279 mPa-s respectively. The mechanical behavior of CNT foam depends on both the intensity of magnetic field and fluid viscosity. The non linear relation between peak stress of CNT and magnetic field intensity is σp(B, η) = σ0 ± α(B-B0) where σ0 is the peak stress at B = B0 , η is the fluid viscosity, parameter α depends on properties of the MR fluid and B0 is an optimum magnetic field for which peak stress is maximum or minimum depending on the fluid viscosity. Graphene is assembled into a three dimensional structure called graphene foam. The graphene foam is infiltrated with polymer and study the detailed compressive behavior of graphene foam and graphene foam/PDMS at different strains of 20, 40, 60 and 70%. The maximum stress and energy absorption capability of graphene foam/PDMS is six times higher than the graphene foam. Also the graphene foam/PDMS is highly stable and reversible for 100 cycles at strains of 30 and 50%. The mechanical behavior of CNT, graphene foam, CNT/PDMS and graphene foam/PDMS is compared. Among all the foams, graphene foam/PDMS has shown the highest elastic modulus as compared to other foams. This behavior can be attributed to the wrinkles formation during the growth of graphene and a coupling between PDMS and interfacial interactions of graphene foam. Therefore it suggests potential applications for dampers, cushions and electronic packaging. Furthermore, the interaction between nanoparticles and polymer in a novel architecture composed of PDMS and iron oxide nanoparticles is studied. The load bearing capacity of uniform composites enhanced by addition of nanoparticles, reaching to a maximum to 1.5 times of the PDMS upon addition of 5wt.% of nanoparticles, and then gradually decreased to 1/6th of PDMS upon addition of 20wt.% of nanoparticles. On the other hand, the load bearing capacity of architectured composites at high strains (≥40%) monotonically increased with addition of nanoparticles in the pillars.

VERÇOSA, Daniel Gomes. Torção natural em nanotubos de carbono de parede simples. 2012. 80 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2012. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-10-16T21:41:19Z No. of bitstreams: 1 2012_dis_dgvercosa.pdf: 3436247 bytes, checksum: 0a1188195cc191e1fbc8767d711104c7 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-10-21T20:37:48Z (GMT) No. of bitstreams: 1 2012_dis_dgvercosa.pdf: 3436247 bytes, checksum: 0a1188195cc191e1fbc8767d711104c7 (MD5) / Made available in DSpace on 2015-10-21T20:37:48Z (GMT). No. of bitstreams: 1 2012_dis_dgvercosa.pdf: 3436247 bytes, checksum: 0a1188195cc191e1fbc8767d711104c7 (MD5) Previous issue date: 2012 / A mais recente revolução tecnológica vem surgindo através de avanços na área da nanotecnologia, onde se destacam materiais nanométricos como os nanotubos de carbono de parede simples (SWNTs). Esse novo material, descoberto em 1993, têm gerado grande interesse acadêmico e industrial devido às suas propriedades físicas únicas. Trabalhos recentes indicam que essas propriedades são extremamente sensíveis a diversos tipos de deformação estruturais, como aquelas de natureza axial, radial e torcional. Neste trabalho estudamos teoricamente como a estrutura eletrônica dos SWNTs, e consequentemente suas propriedades, reagem à presença de torção. Utilizamos o modelo Tight-Biding estendido (ETB) para calcular a estrutura de bandas dos tubos. A simulação de torção é feita a partir de vínculos específicos que altera a componente angular dos vetores primitivos da rede do grafeno. Para obtermos a configuração mais estável dos SWNTs, utilizamos um método denominado gradiente simples modificado de modo a minimizarmos sua energia total. Foi observado que nanotubos quirais apresentam um valor de torção diferente de zero, denominada torção natural, no seu estado fundamental. Essa torção decresce, de forma universal, com o inverso do cubo do diâmetro. Por sua vez, a dependência da torção natural com o ângulo quiral varia de acordo com a metalicidade do SWNT. As energias de transição ótica para o tubo naturalmente torcionado e não torcionado são comparadas, sendo observado variações de até 50% no minigap de tubos metálicos. Por fim, discutimos quais as possíveis implicações da presença da torção natural na ciência por trás dessa nanoestrutura de carbono.

Du fait de leurs propriétés intrinsèques exceptionnelles, les nanotubes de carbone (CNTs) sont des matériaux bien adaptés pour renforcer les polymères thermodurcissables. Le nanocomposite multifonctionnel ainsi obtenu possède des propriétés électriques, thermiques et mécaniques sensiblement meilleures que le polymère seul, ce qui lui procure de nombreuses applications potentielles, et tout particulièrement dans le domaine de l’électronique ou de l’aéronautique. Le but de cette thèse de doctorat est orienté suivant deux axes. Il s’agit dans un premier temps de mettre au point un matériau nanocomposite avec des propriétés multifonctionnelles à partir de techniques d’élaborations efficaces. Puis dans un second temps, l’objectif consiste à proposer des alternatives permettant d’améliorer ces propriétés. Le premier chapitre de cette thèse établit une revue de l’état de l’art au sujet des matériaux qui ont été étudiés au cours de ce travail de recherche. Parmi ces matériaux, nous pouvons citer tout particulièrement les CNTs, les renforts hybrides nano/micrométriques constitués de CNTs et d’alumine, les polymères conducteurs électroniques et les polymères thermodurcissables. Il s’agit plus précisément de présenter pour chaque matériau les techniques d’élaboration, leurs structures et finalement leurs propriétés. Dans la seconde partie du manuscrit, nous décrivons en premier lieu les procédés d’élaboration permettant d’obtenir des nanocomposites conformes aux normes internationales. Ensuite, nous présentons les différentes techniques de caractérisation de ces nanomatériaux. Il s’agit notamment de déterminer les phénomènes de transports électriques et thermiques. Des techniques d’analyses supplémentaires permettent de mieux comprendre la structure des matériaux obtenus dans une gamme d’échelle allant de l’état macroscopique à l’atomique. Ainsi, nous avons eu recours à l’utilisation de la microscopie électronique à balayage et en transmission, et aussi la microscopie à force atomique (AFM). Différentes études spectroscopiques de types : Raman, perte d’énergie des électrons (EELS), photoélectrons X (XPS) fournissent des informations additionnelles sur ces matériaux. Les résultats obtenus sur ces nanocomposites en matière de transports électronique et thermique montrent que certaines améliorations sont nécessaires pour optimiser les propriétés multifonctionnelles de ces nanomatériaux. Nous avons concentré nos efforts sur les phénomènes physicochimiques à l’interface matrice/renfort. Par conséquent, nous avons décidé de modifier la surface des CNTs afin de favoriser la cohésion matrice/renfort, mais aussi et surtout, pour diminuer les résistances de contacts entre les CNTs lorsqu’ils sont distribués aléatoirement dans une matrice polymère. Le dernier chapitre de la thèse s’articule autour de la fonctionnalisation des CNTs par un polymère conducteur électronique (ECP). Dans un premier temps, nous avons mis au point des techniques électrochimiques permettant de déposer une couche homogène d’épaisseur nanométrique d’ECP à la surface des CNTs. Ce polymère conducteur et en même temps biocompatible est le polypyrrole (Ppy). La précision et l’efficacité de notre démarche sont démontrées par les différents outils de caractérisation, et tout particulièrement grâce à la microscopie électronique en transmission à haute résolution. Des études supplémentaires par AFM couplé à un résiscope ont montré l’évolution de la résistance électrique d’hybrides CNT-Ppy plus ou moins isolés. Dans une seconde partie, nous avons mis au point une méthode permettant de contrôler finement l’épaisseur de Ppy déposé à la surface des CNTs. / Carbon nanotubes (CNTs) are ideal candidates to reinforce thermoset polymers due to their exceptional intrinsic properties. The resulting multifunctional nanocomposite has electrical, thermal and mechanical properties sensitively higher than pristine polymer. Therefore, this new material possesses various potential applications, and particularly in the domain of electronics and aerospace. The aim of this PhD thesis is oriented towards two directions. In the first one, we establish efficient techniques to produce composite materials with multifunctional properties. Then, the objective consists in the enhancement of these properties by proposing valuable alternatives to previous results cited in the litterature. In the first chapter, we present the state of the art research concerning the materials studied during this work. Among these, there are in particular: CNTs, hybrids constituted of CNTs and alumina microparticles, electronically conducting and thermoset polymers. Moreover, this chapter deals with the characteristics of each material, i.e. elaboration techniques, structures and properties. The second chapter of the manuscript contains first, the elaboration techniques allowing the synthesis of high quality nanocomposites according to international standards. Then, we analyze the properties of these nanomaterials, and particularly in terms of electrical and thermal transports. Further characterization procedures allow better understanding of the obtained structures in a domain ranging from macroscopic to atomic scales. This is realized using scanning/transmission electron microscopy, Raman spectroscopy, EELS, XPS, and AFM. Electrical and thermal conductivity measurements obtained on these new materials give prominence to the necessity of some improvements. Thereby, we have focused our research on the physico-chemical phenomena at the matrix/filler interface. We have proposed to modify the surface of CNTs, in order to favour the matrix/filler cohesion, but also and mainly to decrease contact resistances between the randomly distributed CNTs within the polymer matrix. Finally, the last chapter deals with the surface functionalization of CNTs using electrochemistry. First, we have implemented an accurate technique to deposit a nanometric layer of electronically conducting polymer on the surface of CNTs. This conducting polymer, namely polypyrrole (Ppy) is in the meantime biocompatible. The accuracy and efficiency of our approach are demonstrated through various characterization techniques, and particularly using transmission electron microscopy. Further studies using AFM coupled with a resiscope indicate the electrical resistance distribution performed on CNT-Ppy hybrids. In the second part of this chapter, we present our method to control precisely the thickness of the Ppy layer around the CNTs.

Made available in DSpace on 2018-06-27T18:56:06Z (GMT). No. of bitstreams: 3 Alexandra Nava.pdf: 7405065 bytes, checksum: 98440f22cb0a32ce958d08b696afa588 (MD5) Alexandra Nava.pdf.txt: 147318 bytes, checksum: 2efcb934aeddafd9aa0074818849ced7 (MD5) Alexandra Nava.pdf.jpg: 3394 bytes, checksum: 0468f8b34b379928f05335b2f501d0b1 (MD5) Previous issue date: 2010-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Carbon nanotubes (CNT) appear as a new class of materials that have special properties and are the focus of many studies in the biological area. Toxicity studies are important to evaluate the biocompatibility and the possible risks of exposure to the CNT. In this context, we evaluated the reproductive toxicity of exposure to multi-walled carbon nanotubes (MWCNT) in pregnant mice. To this end, pregnant females were exposed orally 100 μl MWCNT/day, suspended in PBS / Tween 80® at a concentration of 5 mg/ml and 15 mg/ml during the implantation period (1st to 6th day of pregnancy), organogenesis (7th to 12th day of pregnancy) or during the fetal period (13th to the 18th day of pregnancy). The females were evaluated for changes in weight and consumption of food and water throughout the experiment. In the 18th day of pregnancy, females were undergoing cesarean section and recorded the number of live fetuses, resorptions and dead. The fetuses were weighed, measured and fixed in 70% alcohol (v/v) for analysis of skeletal changes. Maternal organs, liver, kidney, spleen, heart and lung were collected, weighed and fixed in formaldehyde 10% (v/v) for histological analysis. There were mild signs of maternal toxicity, viewed mainly by histological organs and all embryofetal observed changes occurred in animals exposed during the period of organogenesis. Exposure to MWCNT at a dose of 0.5 mg/day showed an increase in the number of resorptions and reduced number of live fetuses in the control group. The exposure to MWCNT 1.5 mg/day showed an increase in the proportion of resorptions, the average of dead fetuses and a reduction in the proportion of live fetuses, resulting in increased rates of prenatal losses. Changes in body weight of fetuses measures were observed in a dosedependent. Analysis of the skeleton showed a marked delay of ossification, also in a dosedependent. These data support the conclusion that exposure to MWCNT at doses of 0.5 mg/day and 1.5 mg/day, cause an increase in losses and prenatal growth retardation, intrauterine, when administered during organogenesis, and these changes may be related to the direct action of the body MWCNT or fetal abnormalities observed in the morphology of the mother's organs. / Os nanotubos de carbono (NTC) surgem como uma nova classe de materiais que apresentam propriedades especiais e estão sendo foco de muitos estudos na área biológica. Estudos de toxicidade tornam-se importantes para avaliação da biocompatibilidade e dos possíveis riscos da exposição à NTC. Neste contexto, avaliou-se a toxicidade reprodutiva da exposição à nanotubos de carbono de paredes múltiplas (NCPM) em camundongos prenhes. Para tanto, fêmeas grávidas foram expostas oralmente a 100 μL NCPM/dia, suspensos em solução de PBS/Tween 80® na concentração de 5mg/mL e 15 mg/mL, durante o período de implantação (1º ao 6º dia de gestação - ddg), organogênese (7º ao 12º ddg) ou durante o período fetal (13º ao 18º ddg). As fêmeas foram avaliadas quanto a alterações de peso e no consumo de água e ração durante todo o experimento. No 18º ddg, as fêmeas foram submetidas à cesariana sendo registrado o número de fetos vivos, mortos e reabsorções. Os fetos foram pesados, medidos e fixados em álcool 70% (v/v) para análise de alterações esqueléticas. Os órgãos maternos, fígado, rim, baço, coração e pulmão foram coletados, pesados e fixados em formol 10% (v/v) para análise histológica. Observaram-se leves sinais de toxicidade materna, visualizados principalmente por alterações histológicas nos órgãos e todas as alterações embriofetais observadas ocorreram nos animais expostos durante o período da organogênese. A exposição à NCPM, na dose de 0,5 mg/dia mostrou aumento no número de reabsorções e redução no número de fetos vivos em relação ao grupo controle. A exposição a 1,5 mg NCPM/dia mostrou o aumento na proporção de reabsorções, na média de fetos mortos e uma redução na proporção de fetos vivos, culminando no aumento do índice de perdas pré natais. Alterações no peso corporal dos fetos foram observadas de forma dose-dependente. A análise do esqueleto demonstrou um intenso retardo de ossificação, também de forma dose dependente. Esses dados permitem concluir que a exposição à NCPM, nas doses de 0,5 mg/dia e 1,5 mg/dia, causam aumento nas perdas pré-natais e retardo de crescimento intra-uterino, quando administrados durante o período da organogênese e essas alterações podem estar relacionadas com a ação direta dos NCPM no organismo embriofetal ou com as alterações observadas na morfologia dos órgãos maternos.

Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-14T19:29:34Z No. of bitstreams: 2 Dissertacao_AlexandreNava.pdf: 7409778 bytes, checksum: e53af9a26d93c0c8d78123589cb1a973 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-08-14T19:29:34Z (GMT). No. of bitstreams: 2 Dissertacao_AlexandreNava.pdf: 7409778 bytes, checksum: e53af9a26d93c0c8d78123589cb1a973 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2010-03-30 / Carbon nanotubes (CNT) appear as a new class of materials that have special properties and are the focus of many studies in the biological area. Toxicity studies are important to evaluate the biocompatibility and the possible risks of exposure to the CNT. In this context, we evaluated the reproductive toxicity of exposure to multi-walled carbon nanotubes (MWCNT) in pregnant mice. To this end, pregnant females were exposed orally 100 μl MWCNT/day, suspended in PBS / Tween 80® at a concentration of 5 mg/ml and 15 mg/ml during the implantation period (1st to 6th day of pregnancy), organogenesis (7th to 12th day of pregnancy) or during the fetal period (13th to the 18th day of pregnancy). The females were evaluated for changes in weight and consumption of food and water throughout the experiment. In the 18th day of pregnancy, females were undergoing cesarean section and recorded the number of live fetuses, resorptions and dead. The fetuses were weighed, measured and fixed in 70% alcohol (v/v) for analysis of skeletal changes. Maternal organs, liver, kidney, spleen, heart and lung were collected, weighed and fixed in formaldehyde 10% (v/v) for histological analysis. There were mild signs of maternal toxicity, viewed mainly by histological organs and all embryofetal observed changes occurred in animals exposed during the period of organogenesis. Exposure to MWCNT at a dose of 0.5 mg/day showed an increase in the number of resorptions and reduced number of live fetuses in the control group. The exposure to MWCNT 1.5 mg/day showed an increase in the proportion of resorptions, the average of dead fetuses and a reduction in the proportion of live fetuses, resulting in increased rates of prenatal losses. Changes in body weight of fetuses measures were observed in a dosedependent. Analysis of the skeleton showed a marked delay of ossification, also in a dosedependent. These data support the conclusion that exposure to MWCNT at doses of 0.5 mg/day and 1.5 mg/day, cause an increase in losses and prenatal growth retardation, intrauterine, when administered during organogenesis, and these changes may be related to the direct action of the body MWCNT or fetal abnormalities observed in the morphology of the mother's organs. / Os nanotubos de carbono (NTC) surgem como uma nova classe de materiais que apresentam propriedades especiais e estão sendo foco de muitos estudos na área biológica. Estudos de toxicidade tornam-se importantes para avaliação da biocompatibilidade e dos possíveis riscos da exposição à NTC. Neste contexto, avaliou-se a toxicidade reprodutiva da exposição à nanotubos de carbono de paredes múltiplas (NCPM) em camundongos prenhes. Para tanto, fêmeas grávidas foram expostas oralmente a 100 μL NCPM/dia, suspensos em solução de PBS/Tween 80® na concentração de 5mg/mL e 15 mg/mL, durante o período de implantação (1º ao 6º dia de gestação - ddg), organogênese (7º ao 12º ddg) ou durante o período fetal (13º ao 18º ddg). As fêmeas foram avaliadas quanto a alterações de peso e no consumo de água e ração durante todo o experimento. No 18º ddg, as fêmeas foram submetidas à cesariana sendo registrado o número de fetos vivos, mortos e reabsorções. Os fetos foram pesados, medidos e fixados em álcool 70% (v/v) para análise de alterações esqueléticas. Os órgãos maternos, fígado, rim, baço, coração e pulmão foram coletados, pesados e fixados em formol 10% (v/v) para análise histológica. Observaram-se leves sinais de toxicidade materna, visualizados principalmente por alterações histológicas nos órgãos e todas as alterações embriofetais observadas ocorreram nos animais expostos durante o período da organogênese. A exposição à NCPM, na dose de 0,5 mg/dia mostrou aumento no número de reabsorções e redução no número de fetos vivos em relação ao grupo controle. A exposição a 1,5 mg NCPM/dia mostrou o aumento na proporção de reabsorções, na média de fetos mortos e uma redução na proporção de fetos vivos, culminando no aumento do índice de perdas pré natais. Alterações no peso corporal dos fetos foram observadas de forma dose-dependente. A análise do esqueleto demonstrou um intenso retardo de ossificação, também de forma dose dependente. Esses dados permitem concluir que a exposição à NCPM, nas doses de 0,5 mg/dia e 1,5 mg/dia, causam aumento nas perdas pré-natais e retardo de crescimento intra-uterino, quando administrados durante o período da organogênese e essas alterações podem estar relacionadas com a ação direta dos NCPM no organismo embriofetal ou com as alterações observadas na morfologia dos órgãos maternos.