Neste trabalho a celulose extraída do bagaço de cana-de-açúcar foi convertida para triacetato de celulose que foi utilizado na produção de nanomembranas obtidas através da técnica de eletrofiação. O acetato de celulose foi preparado adicionando-se 100 mL de ácido acético, 1 mL de ácido sulfúrico e 67 mL de anidrido acético para 1g de celulose do bagaço de cana deaçúcar. Foi obtido um rendimento de cerca de 1,3g do produto para cada 1g de bagaço utilizado no processo. O triacetato de celulose produzido foi caracterizado por meio de Análise de Infravermelho por Transformada de Fourier (FTIR). Os resultados mostraram um conjunto de bandas de baixa intensidade na região 3700 a 3100, uma banda intensa em 1750 cm-1 e uma banda intensa em 1230 cm-1. O grau de substituição foi de 2,8. Os resultados da Calorimetria Exploratória Diferencial (DSC) para a celulose comercial (Sigma®) apresentou dois picos endotérmico a 200ºC e 320ºC e um pico exotérmico a 340ºC, e a celulose do bagaço de cana-de-açúcar mostrou um pico endotérmico a 190ºC. O acetato de celulose comercial (Sigma®) apresentou dois picos endotérmicos a 185ºC e a 240ºC e o triacetato de celulose do bagaço de cana-de-açúcar mostrou quatro picos endotérmicos a 170ºC, 240ºC, 300ºC e 370ºC, respectivamente. As nanomembranas de triacetato de celulose foram produzidas utilizando-se várias soluções poliméricas, a solução polimérica mais adequada ao processo foi Acetona/Dimetilformamida (DMF 85:15 m/m) a 15% de triacetato de celulose 70/30 m/m Sigma®/Bagaço. Durante o processo de eletrofiação foram testadas as seguintes condições: voltagem (25 KV), fluxo (2-4 mL/h) e distância de (7-12 cm). As nanomembranas foram caracterizadas por Microscopia Eletrônica de Varredura (MEV); citotoxicidade onde os resultados obtidos indicando a biocompatibilidade das nanomembranas eletrofiadas; absorção de água, na faixa de 150% a 350% e perda de massa na faixa de 9% a 28%. Neste trabalho também foi realizado o estudo da incorporação da enzima bromelina, visando agregar propriedades cicatrizantes e anti-inflamatórias às nanomembrana e assim possibilitando sua futura utilização no tratamento de feridas, traumas, queimaduras, entre outros. Os melhores resultados na condição em recuperação de atividade enzimática foram de 67,5 / In this work, the cellulose extracted from sugarcane bagasse was converted to cellulose triacetate which was used in the production of nanomembranes obtained by electrospinning technique. The cellulose acetate was prepared by adding 100 mL of acetic acid, 1 mL of sulfuric acid and 67 mL of acetic anhydride to 1 g of cellulose pulp from sugar cane. A yield of about 1.3 g of product per gram of bagasse used in the process was obtained. The cellulose triacetate produced was characterized by analysis of Fourier Transform Infrared Spectroscopy (FTIR). The results show a set of low intensity bands in the region 3700 - 3100, an intense band at 1750 cm-1 and an intense band at 1230 cm-1. The degree of substitution calculated was 2.8. The results of Differential Scanning Calorimetry (DSC) of the commercial cellulose (Sigma®), presented two endothermic peaks at 200ºC, 320ºC and an exothermic peak at 340ºC, and the cellulose from sugarcane bagasse showed the endothermic peak at 190ºC. The commercial cellulose acetate (Sigma®) showed two endothermic peak 185ºC to 240°C and cellulose triacetate from sugarcane bagasse showed four endothermic peaks at 170°C, 240°C, 300°C and 370ºC respectively. The nanomembranes of cellulose triacetate were produced using some polymeric solutions, the polymeric solutions most appropriated was acetone/ dimethylformamide (DMF 85:15 w / w) to 15% cellulose triacetate, cellulose 70/30 w / w Sigma® / Bagasse. During the electrospinning process the following conditions were tested: voltage (25 kV), flow rate (2 - 4 mL/h) and distance (7 - 12 cm). The nanomembranes were characterized by Scanning Electron Microscopy (SEM); cytotoxicity the results indicate the biocompatibility of the electrospinning nanomembranes; and water absorption, yielding values between 150 and 350% mass loss and to values between 9 and 28%. In this study it was the incorporation of the enzyme bromelain, in order to add healing and anti-inflammatory properties to nanomembrane was also performed and thus allowing their future use in the treatment of wounds, traumas, burns, among others. Provided the best results in recovery of enzyme activity was about 67.5

The current study characterizes the mechanical and biodegradation properties of a polycarbonate polyurethane (PU) electrospun nanofiber scaffold intended for use in the growth of a tissue engineered annulus fibrosus (AF) intervertebral disc component. Both the tensile strength and initial modulus of aligned scaffolds were higher than those of random scaffolds and remained unaffected during a 4 week biodegradation study, suggesting a surface-mediated degradation mechanism. The resulting degradation products were non-toxic. Confined compressive mechanical force of 1kPa, was applied at 1Hz to in vitro bovine AF tissue grown on the scaffolds to investigate the influence of mechanical force on AF tissue production, which was found to decrease significantly at 72 hours relative to 24 hours, independent of any effects from mechanical forces. Overall, the consistent rate of PU degradation, along with mechanical properties comparable to those of native AF tissue, and the absence of cytotoxic effects, make this polymer suitable for further investigation for use in tissue-engineering the AF.

The current study characterizes the mechanical and biodegradation properties of a polycarbonate polyurethane (PU) electrospun nanofiber scaffold intended for use in the growth of a tissue engineered annulus fibrosus (AF) intervertebral disc component. Both the tensile strength and initial modulus of aligned scaffolds were higher than those of random scaffolds and remained unaffected during a 4 week biodegradation study, suggesting a surface-mediated degradation mechanism. The resulting degradation products were non-toxic. Confined compressive mechanical force of 1kPa, was applied at 1Hz to in vitro bovine AF tissue grown on the scaffolds to investigate the influence of mechanical force on AF tissue production, which was found to decrease significantly at 72 hours relative to 24 hours, independent of any effects from mechanical forces. Overall, the consistent rate of PU degradation, along with mechanical properties comparable to those of native AF tissue, and the absence of cytotoxic effects, make this polymer suitable for further investigation for use in tissue-engineering the AF.

Le couplage de guides d'ondes nanoscopiques et d'atomes froids a récemment ouvert de nouvelles voies de recherche. Le guide d'onde dans notre cas est une nanofibre qui confine la lumière transversalement à une échelle inférieure à la longueur d'onde. La lumière guidée présente un fort champ évanescent permettant une interaction atome-photon exaltée au voisinage de la nanofibre. Dans notre expérience, un nuage atomique froid est d'abord superposé à une nanofibre optique. Puis, en utilisant un piège dipolaire via le champ évanescent de la nanofibre, les atomes froids sont piégés à proximité de sa surface. Avec cette plateforme, nous avons obtenu des épaisseurs optiques élevées OD ~ 100 et de longues durées de vie ~ 25 ms en utilisant un schéma de piégeage qui préserve les propriétés internes des atomes. Une direction intéressante est alors d'explorer les effets collectifs résultant de l'ordre spatial des atomes. Lorsque la période du réseau est proche de la longueur d'onde de résonance, une réflexion de Bragg aussi élevée que 75% est observée. Cette réflexion dépend de la polarisation de la sonde par rapport aux réseaux atomiques - une signature de la chiralité dans les systèmes à guide d'ondes nanoscopiques. La possibilité de contrôler le transport de photons dans les guides d'ondes couplés à des systèmes de spin permettrait de nouvelles fonctionnalités pour les réseaux quantiques et l'étude d'effets collectifs résultant d'interactions à longue distance. / The coupling of cold atoms to 1D nanoscale waveguides have opened new avenues of research. The waveguide in our case is a nanofiber, which confines light transversally to a subwavelength scale. The guided light exhibits a strong evanescent field allowing enhanced atom-photon interaction in the vicinity of nanofiber. In our experiment, a cold atomic cloud is first interfaced with an optical nanofiber. By using an optical lattice in the evanescent field, the atoms are then trapped in 1D atomic arrays close to the nanofiber. In this platform, we reach high optical depth OD ~ 100 and long lifetimes ~ 25 ms by using a dual-color compensated trapping scheme that preserves the internal properties of atoms. In this thesis, we explore collective effects emerging from the spatial ordering of atoms. When the period of the lattice is made close to commensurate with the resonant wavelength, Bragg reflection, as high as 75%, is observed. The reflection shows dependency on orientation of the probe polarization relative to the atomic arrays - a chiral signature in nanoscale waveguide-QED systems. The ability to control photon transport in 1D waveguides coupled to spin systems would enable novel quantum networking capabilities and the study of many-body effects arising from long-range interactions.

Neste trabalho a celulose extraída do bagaço de cana-de-açúcar foi convertida para triacetato de celulose que foi utilizado na produção de nanomembranas obtidas através da técnica de eletrofiação. O acetato de celulose foi preparado adicionando-se 100 mL de ácido acético, 1 mL de ácido sulfúrico e 67 mL de anidrido acético para 1g de celulose do bagaço de cana deaçúcar. Foi obtido um rendimento de cerca de 1,3g do produto para cada 1g de bagaço utilizado no processo. O triacetato de celulose produzido foi caracterizado por meio de Análise de Infravermelho por Transformada de Fourier (FTIR). Os resultados mostraram um conjunto de bandas de baixa intensidade na região 3700 a 3100, uma banda intensa em 1750 cm-1 e uma banda intensa em 1230 cm-1. O grau de substituição foi de 2,8. Os resultados da Calorimetria Exploratória Diferencial (DSC) para a celulose comercial (Sigma®) apresentou dois picos endotérmico a 200ºC e 320ºC e um pico exotérmico a 340ºC, e a celulose do bagaço de cana-de-açúcar mostrou um pico endotérmico a 190ºC. O acetato de celulose comercial (Sigma®) apresentou dois picos endotérmicos a 185ºC e a 240ºC e o triacetato de celulose do bagaço de cana-de-açúcar mostrou quatro picos endotérmicos a 170ºC, 240ºC, 300ºC e 370ºC, respectivamente. As nanomembranas de triacetato de celulose foram produzidas utilizando-se várias soluções poliméricas, a solução polimérica mais adequada ao processo foi Acetona/Dimetilformamida (DMF 85:15 m/m) a 15% de triacetato de celulose 70/30 m/m Sigma®/Bagaço. Durante o processo de eletrofiação foram testadas as seguintes condições: voltagem (25 KV), fluxo (2-4 mL/h) e distância de (7-12 cm). As nanomembranas foram caracterizadas por Microscopia Eletrônica de Varredura (MEV); citotoxicidade onde os resultados obtidos indicando a biocompatibilidade das nanomembranas eletrofiadas; absorção de água, na faixa de 150% a 350% e perda de massa na faixa de 9% a 28%. Neste trabalho também foi realizado o estudo da incorporação da enzima bromelina, visando agregar propriedades cicatrizantes e anti-inflamatórias às nanomembrana e assim possibilitando sua futura utilização no tratamento de feridas, traumas, queimaduras, entre outros. Os melhores resultados na condição em recuperação de atividade enzimática foram de 67,5 / In this work, the cellulose extracted from sugarcane bagasse was converted to cellulose triacetate which was used in the production of nanomembranes obtained by electrospinning technique. The cellulose acetate was prepared by adding 100 mL of acetic acid, 1 mL of sulfuric acid and 67 mL of acetic anhydride to 1 g of cellulose pulp from sugar cane. A yield of about 1.3 g of product per gram of bagasse used in the process was obtained. The cellulose triacetate produced was characterized by analysis of Fourier Transform Infrared Spectroscopy (FTIR). The results show a set of low intensity bands in the region 3700 - 3100, an intense band at 1750 cm-1 and an intense band at 1230 cm-1. The degree of substitution calculated was 2.8. The results of Differential Scanning Calorimetry (DSC) of the commercial cellulose (Sigma®), presented two endothermic peaks at 200ºC, 320ºC and an exothermic peak at 340ºC, and the cellulose from sugarcane bagasse showed the endothermic peak at 190ºC. The commercial cellulose acetate (Sigma®) showed two endothermic peak 185ºC to 240°C and cellulose triacetate from sugarcane bagasse showed four endothermic peaks at 170°C, 240°C, 300°C and 370ºC respectively. The nanomembranes of cellulose triacetate were produced using some polymeric solutions, the polymeric solutions most appropriated was acetone/ dimethylformamide (DMF 85:15 w / w) to 15% cellulose triacetate, cellulose 70/30 w / w Sigma® / Bagasse. During the electrospinning process the following conditions were tested: voltage (25 kV), flow rate (2 - 4 mL/h) and distance (7 - 12 cm). The nanomembranes were characterized by Scanning Electron Microscopy (SEM); cytotoxicity the results indicate the biocompatibility of the electrospinning nanomembranes; and water absorption, yielding values between 150 and 350% mass loss and to values between 9 and 28%. In this study it was the incorporation of the enzyme bromelain, in order to add healing and anti-inflammatory properties to nanomembrane was also performed and thus allowing their future use in the treatment of wounds, traumas, burns, among others. Provided the best results in recovery of enzyme activity was about 67.5

Différents matériaux carbonés nanostructurés ont été synthétisés et mis en oeuvre comme matériaux supercapacitifs à double couche électrochimique (EDLC) ou comme substrats de matériaux pseudocapacitifs avec pour objectif d'augmenter leur densité de puissance. Nous avons ainsi développé une méthode de synthèse simple et originale de carbures de silicium (SiC) qui procède par une réduction topotactique d'un composite silice/carbon par le magnésium. Du fait de la température de synthèse inférieure à 800°C, SiC résultant conserve la morphologie et/ou la structure poreuse du précurseur composite. Par cette approche, nous pouvons moduler la structure poreuse ordonnée de SiC à façon, développer des porosités hiérarchiques méso/macro, préparer des feuillets ou des fibres de SiC. Les différentes formes de SiC ont été converties par chloration en autant de carbones, opération introduisant une microporosité supplémentaire. En électrolyte organique, ces carbones à porosité hierarchique combinent à la fois des capacités importantes issues de la microporosité mais également des performances inégalées en terme de puissance du fait de la méso ou macro-porosité associée. Dans une approche différente, des feuillet de graphène ont été décorés par voie sol-gel non-hydrolytique (micro-onde en milieu alcool benzilique) par des nanoparticules de FeOx. Le composite FeOx/graphene résultant combine simultanément les comportements EDLC et pseudocapacitif du graphène et de FeOx. Du fait de sa structure particulière, le composite FeOx/graphene conserve les performances en puissance du graphène auxquelles s'ajoutent celles d'énergie de FeOx. Nous avons également décoré des nanofibres de carbone avec des carbones mésoporeux. Après dépôt de MnO2 birnessite, les composites gagnent à la fois en capacité et en puissance en particulier avec des carbones présentant des pores supérieurs à 10nm. / Various nanostructured carbon materials were synthesized and further served as active materials of electrical double layer capacitor or substrates of pseudocapacitive materials in order to improve power capability of corresponding supercapacitor. On the one hand, a simple synthesis of porous silicon carbides (SiCs) was achieved by performing a topotactic thermal reduction by magnesium (Mg) of a silica/ carbon composite. Thanks to the low synthetic temperature (below 800 ºC), the SiCs well preserved the pristine skeletons of their silica/carbon precursors. Successively, the SiCs with diverse porous structures from their silica/carbon precursor emerged, e.g. ordered tunable mesoporous SiCs, 3D-hierarchical meso and macroporous SiC, SiC nanosheet and SiC nanofiber. Furthermore, the porous SiCs derived from magnesio-thermal reduction were reduced to hierarchical carbons with newborn narrow distributed microporosity by chlorination. In an organic electrolyte, the hierarchical carbon combines the high specific capacitance from narrow distributed microporosity and the outstanding rate capability from ordered-arranged meso or macroporosity that make it promising for high power and energy density capacitor. On the other hand, a “benzyl alcohol route” has been used to decorate RGO nanosheets with FeOx nanoparticles. The resulting FeOx/ RGO composite, due to their hybrid nanostructure, combine both EDLC capacitive and pseudocapacitive bahaviors of RGO and FeOx, respectively. Thanks to the laminated RGO and nano FeOx particles film, the resulting composite gains the same power capability as RGO and a higher energy density than raw FeOx. Furthermore, mesoporous carbon was introduced to adorn the CNF surface through self-assemble of resol, carbon nanofiber(CNF) and Pluronic@127. After further coating with birnessite-MnO2, the composite electrode gains extra capacitance and power improvement in presence of superficially coating mesoporous carbon with pore size larger than 10nm.

Cette thèse a consisté à mettre en place une nouvelle expérience utilisant des atomes froids en interaction avec la lumière guidée par une nanofibre optique. Nous avons tout d'abord développé un banc de fabrication de nanofibres. En chauffant et étirant une fibre optique commerciale, on obtient un cylindre de silice de 400 nm de diamètre. La lumière guidée dans ces nanofibres est fortement focalisée sur toute la longueur de la fibre et exhibe de forts champs évanescents, ce qui permet d'obtenir une grande profondeur optique avec un faible nombre d'atomes. Après avoir inséré une nanofibre au milieu d'un nuage d'atomes, nous avons observé le phénomène de lumière lente dans les conditions de transparence électromagnétiquement induite. Nous avons aussi stoppé la lumière guidée et mémorisé l'information qu'elle contenait. Nous avons montré que ce protocole de mémoire optique fonctionne pour des impulsions lumineuses contenant moins d'un photon en moyenne. Ce système pourra donc être utilisé comme une mémoire quantique, un outil essentiel pour les futurs réseaux de communication quantique. Enfin, nous avons piégé les atomes dans un réseau optique au voisinage de la nanofibre grâce à de la lumière guidée par celle-ci. Par rapport à notre première série d'expériences, le nuage ainsi obtenu a un temps de vie plus long (25 ms) et interagit plus fortement avec la lumière guidée (OD ~ 100). Ce nouveau système devrait permettre d'implémenter efficacement d'autres protocoles d'optique quantique, comme la génération de photons uniques et l'intrication de deux ensembles atomiques distants. / We built a new experiment using cold atoms interacting with the light guided by an optical nanofiber. We first developed a nanofiber manufacturing bench. By heating and stretching a commercial optical fiber, a silica cylinder of 400 nm diameter is obtained. The light guided in these nanofibers is strongly focused over the whole length and exhibits strong evanescent fields. We then prepared a vacuum chamber and the laser system necessary for the manipulation of cold atoms. After inserting a nanofiber amid a cloud of cold atoms, we observed the phenomenon of slow light under the conditions of electromagnetically induced transparency: the light guided by the fiber is slowed down to a speed 3000 times smaller than its usual speed. We also stored the light guided by an optical fiber. After several microseconds, the information stored as a collective atomic excitation could be retrieved in the fiber. We have shown that this optical memory works for light pulses containing less than one photon on average. This system may therefore be used as a quantum memory, an essential tool for future quantum communication networks. Finally, we trapped atoms in an array in the vicinity of the nanofiber thanks to the light guided by the latter. Compared to our first set of experiments, the resulting cloud has a longer lifetime (25 ms) and interacts more strongly with the guided light (OD ~ 100). This new system should allow to efficiently implement other quantum optics protocols, such as the generation of single photons, or the entanglement of two remote atomic ensembles.

The diploma thesis is focused on the study of fibrous wound dressings prepared by electrospinning method from natural biopolymers. Three active ingredients were added to the dressings: ampicillin, ibuprofen and collagenase, which are responsible for relieving pain, reducing the risk of infection and selectively removing necrotic tissue in the wound. The theoretical part describes the therapeutic dressings currently available on the market and the most common methods of nanofiber production. The experimental part evaluates the optimization of the preparation of gelatin, alginate and chitosan fibrous wound dressings, which were subsequently enriched with active substances and their gradual release into the model environment was determined spectrophotometrically. Antimicrobial effects against E.coli and S. epidermidis strains andantifungal activity against C. glabrata yeast were monitored. Finally, two cytotoxicity tests on the human keratinocyte cell line HaCaT confirmed the safety of the prepared products, which can serve as bioactive skin dressings in the future.

Blood vessel mimics (BVMs) are simple tissue engineered blood vessel constructs intended for preclinical testing of vascular devices. This thesis developed and implemented methods to characterize two of these components. The first aim of this thesis investigated the effect of cell culture duration and flow conditions on endothelial cell gene expression, especially regarding endothelial-to-mesenchymal transition (EndMT). A trend of decreased endothelial marker gene expression and increased mesenchymal marker gene expression would indicate EndMT. qPCR analysis revealed that increased cell culture duration did not result in EndMT, and in fact increased endothelial marker expression as cell culture duration increased. Disturbed flow conditions decreased endothelial marker and increased mesenchymal marker expression relative to static culture. The second aim of this thesis developed methods to determine cytotoxicity of, and endothelial cell adhesion to, novel BTEAC salt scaffolds. Immunostaining was used to visualize these scaffold effects. The cytotoxicity elution assay showed that BTEAC salt scaffolds were not more cytotoxic than the standard PLGA scaffold. Direct contact assays spanning several timepoints also found that BTEAC salt scaffolds were not more cytotoxic than standard scaffolds but had higher endothelial cell adhesion and coverage than standard scaffolds. Overall, this thesis developed and implemented methods to characterize the endothelial cells used in the BVM model.

The doctoral thesis „Using of nanofiber filter for air filtration“ is focused on application of nanofiber filter for air filtration under demanding conditions of water supply facilities. The main aim of the filter application is to decrease the secondary contamination of the indoor environment of the water accumulation tanks. The nanofiber filters are distinguished by high filtration efficiency of pollutants, dust particles and organic impurities. The contaminants don´t have to be unhealthy but they can be used for spore and microorganisms delivery to the system. They are served frequently as a reproduction substrate of microorganisms. All these factors negatively affect the water quality. The research includes formation of suitable testing methodology, pilot unit construction and operation, short-term testing and evaluation of nanofiber filters and commonly used filters and long term testing and verification of nanofiber filter attributes and quality. Furthermore the filter´s characteristics and filtration efficiency for characteristic pollutants were evaluated. Short-term and long-term experimental testing proved suitability of nanofiber filters use in water supply facilities. Interception of reported pollution indicators was reported on similar or higher level for application of nanofiber filter than for application of commonly used filter. Measured values of higher pressure difference of nanofiber filter were indicated as still adequate for use in water supply facilities. No operation difficulties, failures neither filter´s damage were reported during testing of nanofiber filters.