Disponibiliza??o em conte?do parcial do trabalho, conforme Termo de Autoriza??o. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-02-14T19:00:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) lays_fernanda_nunes_dourado_parcial.pdf: 389665 bytes, checksum: 2289d8ac4ca389d5cdaf516878ddae78 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-03-06T12:24:50Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) lays_fernanda_nunes_dourado_parcial.pdf: 389665 bytes, checksum: 2289d8ac4ca389d5cdaf516878ddae78 (MD5) / Made available in DSpace on 2017-03-06T12:24:50Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) lays_fernanda_nunes_dourado_parcial.pdf: 389665 bytes, checksum: 2289d8ac4ca389d5cdaf516878ddae78 (MD5) Previous issue date: 2016 / Na ind?stria farmac?utica, os pol?meros s?o capazes de desempenhar a fun??o de matriz para libera??o controlada de f?rmacos. Isto tem como vantagem a minimiza??o dos efeitos adversos dos medicamentos e a otimiza??o do tratamento. Entre os pol?meros utilizados para tal finalidade, tem-se o poli(3-hidroxibutirato) (PHB) conhecido por sua origem natural, um material que se degrada a produtos n?o t?xicos para o organismo, o que garante o seu emprego como biomaterial. Quando utilizado em associa??o a outros pol?meros, s?o denominados Blendas, essas misturas modificam as caracter?sticas f?sico-qu?micas dos pol?meros para serem empregados em finalidades diversas. Desta forma este trabalho teve como objetivo o desenvolvimento de uma matriz polim?rica capaz de ser utilizada para libera??o controlada de f?rmacos. Para tal, foram produzidas duas membranas diferentes uma de PHB e outra de Blenda Poli (3-hidroxibutirato)/Polipropilenoglicol, PHB/PPG (90:10), com concentra??es diferentes de f?rmaco, contendo 5% e 25% em massa. O f?rmaco modelo foi a Sinvastatina. Estes dispositivos foram produzidos por dissolu??o seguida de evapora??o do solvente, formando filmes de 0,5 mm de di?metro que foram analisados quanto a sua degrada??o in vitro e in vivo, em implantes subcut?neos. Os materiais foram analisados utilizando espectroscopia na regi?o do infravermelho, termogravimetria, microscopia eletr?nica de varredura e por testes histol?gicos. Os filmes ? base de PHB, apresentaram degrada??o in vitro e in vivo mais lenta quando comparados ?s blendas, no entanto em ambos os casos, os materiais que continham maior percentual de Sinvastatina apresentaram maior degrada??o e libera??o do f?rmaco. As l?minas histol?gicas revelam a presen?a do tecido em torno dos dispositivos e aus?ncia de inflama??o o que comprova a biocompatibilidade dos materiais estudados. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncias Farmac?uticas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / In the pharmaceutical industry, the polymers are able to drive the controlled release of drugs. Its brings the advantage of minimizing adverse effects of medicines and optimization of treatment. Among the polymers used for this purpose the poly (3-hydroxybutyrate) has known for their natural origin, its degradation to non-toxic effects to the life tissue which ensures their use as subcutaneous implants. A blend is a mixture of different polymers, these mixtures are able to modify the physicochemical characteristics of the polymers for several uses. This study aimed to develop a polymer matrix can be used as a way for controlled release of drugs. For this purpose, two different membranes were produced, the PHB and a Poly(3-hydroxybutyrate)/Polypropylene glycol blends, PHB/PPG (90:10), with different concentrations of drug with 5% and another 25%. The simvastatin was chosen as a model. These devices were manufactured by casting to form films of 0.5 mm diameter that were analyzed for in vitro and in vivo degradation tests using subcutaneous implants. The materials were analyzed using infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and histological tests. The films based on PHB presented a slower degradation in vitro and in vivo degradation tests when compared to the blends, however in both cases those materials containing a higher percentage of simvastatin has shown the higher degradation and release of the drug. The histological sections showed a tissue colonization and absence of inflammation which demonstrates the biocompatibility of the implants.

Philosophiae Doctor - PhD / In this thesis, regioregularpoly( 3-hexylthiophene) (rr-P3HT) polymer was used as a light absorption and electron donating material, while the C60 fullerene and its derivative [6,6]-phenyl C61-butyric acid methyl ester (PCBM) were used as electron acceptor materials. The effect of solvent to control the degree of mixing of the polymer and fullerene components, as well as the domain size and charge transport properties of the blends were investigated in detail using P3HT:C60 films. The photo-physical, structural and electrical transport properties of the polymer blends were carried out according to their ratios. A distinctive photoluminescence (PL) quenching effect was observed indicating a photo-induced electron transfer. In this thesis, the effect of solvents on the crystallization and interchain interaction of P3HT and C60 fullerene films were studied using XRD, UV-vis, PL, Raman and FTIR spectroscopy. The polymer blends formed with non-aromatic solvents exhibited an improved crystallinity and polymer morphology than that formed with aromatic solvents. An improved ordering was demonstrated in the polymer films spin coated from non-aromatic solvents. This indicates that the limited solubility of rr P3HT in a marginal solvent such as non-aromatic solvents can offer a strategy to obtain highly ordered crystal structures and lead directly to optimal morphologies on the films. / South Africa

Orientador: Marcos Akira D' Ávila / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-24T19:12:36Z (GMT). No. of bitstreams: 1 Almeida_RosemeiredosSantos_D.pdf: 3414008 bytes, checksum: 9f5516445d3c90d0f22d3a953197d6b7 (MD5) Previous issue date: 2014 / Resumo: O polímero Poli(caprolactona) (PCL) tem sido amplamente usado como biomaterial nas últimas décadas. Sua biocompatibilidade e boas propriedades termo-mecânicas são as principais características que levam à seleção desse material para aplicação nas áreas biotecnológica, farmacêutica e têxtil. Neste trabalho, montou-se um equipamento para realizar o processamento de eletrofiação e caracterização de mantas formadas por fibras de PCL puro e nanocompósitos de PCL/nanotubos de carbono (NTC). Recorreu-se à eletrofiação com a aplicação de um campo elétrico gerado por uma corrente alternada (CA) e por uma corrente contínua (CC) simultaneamente (CA/CC) visando o controle da estabilidade do escoamento do jato polimérico durante o processamento a fim de determinar os parâmetros de processo e comparar os efeitos das diferentes frequências durante o processamento. Foram obtidos também nanocompósitos de PCL/óxido de grafeno (GO) com aplicação de um potencial elétrico em corrente contínua (CC), a fim de determinar os parâmetros de processos em diferentes concentrações de óxido de grafeno. As soluções/suspensões utilizadas no processo foram caracterizadas através de medições de condutividade elétrica, tensão superficial e propriedades reológicas. As fibras obtidas na forma de mantas porosas não-tecidas (non woven) foram caracterizadas por Microscopia Eletrônica de Varredura (MEV), Espectroscopia de Infravermelho com Transformada de Fourier (FT-IR), Calorimetria Exploratória Diferencial (DSC), Análise Termogravimétrica (TGA), Resistividade, Ângulo de contato ensaios mecânicos de tração e ensaios biológicos in vitro com células tronco mesenquimais humanas (hMSCs). Observou-se que o diâmetro médio das fibras depende da frequência CA aplicada durante a eletrofiação. A análise por FT-IR mostrou que houve a interação entre o PCL e o NTC, e as análises biológicas indicaram que as mantas PCL/GO são promissoras para uso como biomaterial / Abstract: Poly (??caprolactone) (PCL) has been widely used as biomaterial in the last decades. Its biocompatibility and good thermomechanical properties are the main features that lead to the selection of this material for applications in biotechnological, pharmaceutical and textile areas. In this work, an equipment was set up to perform electrospinning; characterization of fibrous mats formed by pure PCL fibers and nanocomposites of PCL/carbon nanotubes (CNT). Electrospinning based on the application of an electric field generated by an alternating current (AC) and a direct current (DC) simultaneously (AC/DC) was performed aiming to control the stability of the jet flow of the polymer during processing in order to determine the process parameters and compare the effects of different frequencies during processing. Nanocomposites of PCL/graphene oxide (GO) with application of a DC electrical potential were also obtained in order to determine the process parameters at different concentrations of graphene oxide. Solutions/suspensions employed in the process were characterized by measurements of electrical conductivity, surface tension and rheological properties. The fibers obtained in the form of non- woven porous mats were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential canning Calorimetry (DSC), Thermogravimetric Analysis (TGA), resistivity, contact angle and mechanical properties was measured, and in vitro biological assays with human mesenchymal stem cells (hMSCs) was evaluated. It was observed that the average diameter of the fibers depends on the AC frequency applied during electrospinning. The FT-IR analysis showed that there was interaction between the PCL and the CNTs, and biological analysis indicated that the blankets of PCL/CNT and PCL/GO are promising for use as a biomaterial / Doutorado / Materiais e Processos de Fabricação / Doutora em Engenharia Mecânica

In smart textiles, electrical conductivity is often required for several functions, especially contacting (electroding) and interconnecting. This thesis explores electrically conductive textile surfaces made by combining conventional textile coating methods with the intrinsically conductive polymer complex poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS). PEDOT:PSS was used in textile coating formulations including polymer binder, ethylene glycol (EG) and rheology modifier. Shear viscometry was used to identify suitable viscosities of the formulations for each coating method. The coating methods were knife coating, pad coating and screen printing. The first part of the work studied the influence of composition of the coating formulation, the amount of coating and the film formation process on the surface resistivity and the surface appearance of knife-coated textiles. The electrical resistivity was largely affected by the amount of PEDOT:PSS in the coating and indicated percolation behaviour within the system. Addition of a high-boiling solvent, i.e. EG, decreased the surface resistivity with more than four orders of magnitude. Studies of tear strength and bending rigidity showed that textiles coated with formulations containing larger amounts of PEDOT:PSS and EG were softer, more ductile and stronger than those coated with formulations containing more binder. The coated textiles were found to be durable to abrasion and cyclic strain, as well as quite resilient to the harsh treatment of shear flexing. Washing increased the surface resistivity, but the samples remained conductive after five wash cycles. The second part of the work focused on using the coatings to transfer the voltage signal from piezoelectric textile fibres; the coatings were first applied using pad coating as the outer electrode on a woven sensor and then as screen-printed interconnections in a sensing glove based on stretchy, warp-knitted fabric. Sensor data from the glove was successfully used as input to a microcontroller running a robot gripper. These applications showed the viability of the concept and that the coatings could be made very flexible and integrated into the textile garment without substantial loss of the textile characteristics. The industrial feasibility of the approach was also verified through the variations of coating methods.

Organic electronics based on π-conjugated semi-conductor raises new technology, such as organic film transistors, e-paper, and organic photovoltaic cells that can be implemented cost-effectively on large-area applications. Currently, the device performance is limited by low charge carrier mobility. Poly(3-hexylthiophene) (P3HT) and organic field effect transistors (OFET) is used as a model to investigate morphology of the organic film and corresponding electronic properties. In this thesis, processing parameters such as boiling points and solubility are controlled to impact the micro- and macro-morphology of the film to enhance the charge transport of the device. Alternative approach to improve ordering of polymer chains and increase in charge transport without post-treatment of P3HT solution is studied. The addition of high boiling good solvent to the relatively low boiling main solvent forms ordered packing of π-conjugated polymers during the deposition process. We show that addition of 1% of dichlorobenzene (DCB) to the chloroform based P3HT solution was sufficient to improve wetting and molecular structures of the film to increase carrier mobility. Systematic study of solvent-assisted re-annealing technique, which has potential application in OFET encapsulation and fabrication of top-contact OFET, is conducted to improve mobility of OFET, and, to suggest a cost-effective processing condition suitable for industrial application. Three process parameters: boiling point, polarity, and solubility are investigated to further understand the trend of film response to the solvent-assisted technique. We report the high boiling non-polar solvents with relatively high RED values promote highest improvement in molecular packing and formulate crystalline structure of the thin film, which increases the device performance.

Electrically conductive or electro-active fibers are the key components of smart and interactive textiles, which could be used in medical, sports, energy, and military applications in the near future. The functionalization of high-performance textile yarns/fibers with conjugated polymers can produce conductive fibers with better electro-mechanical properties, which is difficult with commonly used spinning techniques. In this thesis work, textile-based conductive yarns/fibers were prepared by coating viscose and polyester (PET) yarns with the conjugated polymer PEDOT. For coating purposes, an efficient technique called chemical vapor deposition (CVD) was used, which is a solventless technique and can produce PEDOT polymer layers with high conductivity values. The polymerization of EDOT monomer vapors and coating of oxidant (FeCl3 or FepTS) enriched viscose and PET yarns took place simultaneously. The PEDOT-coated viscose and polyester yarns showed relatively high conductivity values, which could be sufficient for many electronic applications. The polymerization process and the quality of PEDOT polymer strongly depends on different reaction conditions. In this research work, the impact of most of these reaction parameters on the electrical, mechanical, and thermal properties of PEDOT-coated conductive yarns was considered separately. Under specific reaction conditions, it was found that viscose fibers were successfully coated with PEDOT polymer and showed rather high electrical conductivity (≥ 15 S/cm). However, due to the acid hydrolysis of viscose fibers in FeCl3 solutions, the mechanical properties were drastically reduced. In order to improve the mechanical properties of conductive yarns, a relatively stable and chemical-resistant substrate (PET) was coated with PEDOT polymer. Comparative studies between PEDOT-coated viscose and PET conductive yarns showed that the electrical and mechanical properties were enhanced by changing the substrate material. Later on, PEDOT-coated conductive fibers were treated with silicone elastomer solution and due to the thin silicone layers, the hydrophobic properties, flexibility, and durability of coated yarns was improved. Furthermore, a novel electrical resistance-measuring setup was developed, which can be used not only for fibers but also for fabric structures. The electrical characterization of PEDOT-coated conductive yarns showed that it can be used effectively for sensitive fibers without damaging their surface morphology. Finally, the use of conductive yarns as stretch sensors was evaluated. For this purpose, small rectangular knitted patches of conductive yarns were prepared and then the change in electrical resistance values at different extension percentages (5–50%) was investigated. The constant variations in electrical resistance values at different extension and relaxation cycles for longer periods of time revealed that the conductive yarns produced have the potential to be used as stretch sensors for monitoring of vital signs in medical and sports applications. / <p>Thesis for the Degree of Doctor of Philosophy to be presented on March 08, 2013, 10.00 in KA-salen, Kemigården 4, Chalmers University of Technology, Gothenburg</p>

O objetivo deste trabalho foi o estudo das propriedades mecânicas e térmicas do PHB e de compósitos de PHB/pó de madeira processados, reprocessados e irradiados. Foram preparados compósitos com PHB e pó de madeira com concentrações de PHB/pó de madeira de 90/10, 80/20 e 70/30 (m/m). Foram realizados ensaios de propriedades mecânicas, HDT, ponto de amolecimento Vicat, TGA e DSC. A incorporação do pó de madeira aumentou o grau de cristalinidade e a temperatura de cristalização do polímero, e nos compósitos PHB/pó de madeira 80/20 e 70/30 a rigidez do material aumentou em relação ao polímero puro. O compósito PHB/pó de madeira 70/30 apresentou os melhores resultados em termos econômicos, de processamento e de estabilidade em relação ao reprocessamento. A irradiação após o processamento, em dose de 30 kGy, provocou aumento da rigidez do PHB puro e dos compósitos PHB/pó de madeira 90/10 e 80/20, embora as outras propriedades tenham decrescido. O compósito PHB/pó de madeira 70/30 apresentou queda de todas as propriedades com a irradiação. / The purpose of this work was the study of the mechanical and thermal properties of processed, reprocessed and irradiated PHB, as well as PHB/wood flour composites. PHB/wood flour composites were prepared with PHB/wood relation of 90/10, 80/20 e 70/30 (w/w). Mechanical properties, HDT, Vicat melting point and thermo analyses (TGA and DSC) tests were carried out. The introduction of the wood flour increased both polymer crystallinity and crystallization temperature. The material stiffness increased in PHB/wood flour composites (80/20 and 70/30) resulting in higher values in some properties when compared with pure PHB. The PHB/wood flour composite 70/30 showed the best results in terms of economy, processing and stability during reprocessing. The irradiation after processing in 30kGy doses led to a stiffness increasing of pure PHB and PHB/wood flour composites (90/10 and 80/20) while other properties have decreased. The PHB/wood flour 70/30 showed decreasing in all properties after irradiation.

O sistema de mobilização intracelular de poli-3-hidroxibutirato (P3HB) em Burkholderia sacchari foi analisado. A busca em genomas de Burkholderia spp. identificou duas oligômero hidrolases (PhaY1 e PhaY2) e pelo menos três P3HB despolimerases intracelulares (PhaZa1, PhaZa2 e PhaZd1). Mutantes de B. sacchari afetados na mobilização de P3HB e complementados com genes de Ralstonia eutropha apresentaram um aumento expressivo nas taxas de mobilização de P3HB, especialmente quando o gene phaZa1 foi superexpresso. A superexpressão dos genes phaZa2 ou phaZa3 também conduziu a aumentos nas taxas de mobilização embora em um grau menor que os valores obtidos com phaZa1. Dois mutantes afetados na mobilização de P3HB foram obtidos utilizando o transposon mini-Tn5 (NAM03 e NAM04). NAM03 apresentou interrupção em gene que codifica uma P3HB despolimerase intracelular (PhaZa1). NAM04 apresentou interrupção em gene anotado como serino peptidase LonA. Este pode representar um ativador da mobilização ou uma nova P3HB despolimerase intracelular. / The intracellular poly-3-hydroxybutyrate (P3HB) mobilization system in Burkholderia sacchari was analyzed. A search in Burkholderia spp. genomes identified two oligomer hydrolases (PhaY1 and PhaY2) and at least three intracellular P3HB depolymerase (PhaZa1, PhaZa2 e PhaZd1). B. sacchari mutants affected on P3HB mobilization and complemented by Ralstonia eutropha genes showed an expressive increase on P3HB mobilization rates, especially when phaZa1 was overexpressed. The overexpression of phaZa2 or phaZa3 also increased the mobilization rates though to a lesser extent than phaZa1. Two mutants affected on P3HB mobilization were obtained using the transposon mini-Tn5 (NAM03 and NAM04) .NAM03 was disrupted in a gene encoding an intracellular P3HB depolymerase (PhaZa1). NAM04 was disrupted in a gene annotated as a serine peptidase LonA. This could be a mobilization activator or a new intracellular P3HB depolymerase.

Externally initiated o-tolyl initiated poly(3-hexylthiophene) (P3HT) was synthesized according to Grignard metathesis polymerization at varying chain length to compare number average molecular weights (Mn) obtained by gel permeation chromatography (GPC) and 1H NMR end group analysis. The extent of overestimation by GPC (1.3) was determined to be lower than previously reported for low Mn polymers. However, an apparent GPC quantification limit was observed as NMR Mn correlated well to predicted results. Static light scattering studies on high Mn polymers provided evidence that the true molecular weight was more similar to GPC-derived Mn. Despite nearly 100% external initiation efficiency, at a certain Mn limit new uninitiated chains may be synthesized. It is suggested that the synthesis of externally initiated P3HT should be limited to Mn below 40 kDa to ensure fully externally initiated chains. A proposal for the synthesis of externally initiated macrocyclic P3HT will also be discussed.

Les structures poreuses tridimensionnelles fonctionnelles possèdent un fort potentiel dans de nombreuses applications biomédicales. Nous avons ainsi orienté nos travaux vers l'élaboration de nouveaux matériaux capables de répondre à plusieurs critères pour l'ingénierie tissulaire osseuse. Du fait de leur biodisponibilité, leur biocompatibilité et leur biodégradabilité, les poly(3-hydroxyalcanoate)s (PHAs) présentent des propriétés particulièrement adaptées pour ce type d'application. Dans un premier temps, nous avons développé de nouvelles stratégies contrôlées, rapides et aisées, de synthèse de copolymères à blocs à base de PHAs ainsi que de production d'oligoesters par activation sous micro-ondes. Par ailleurs, l'absence d'effet " non-thermique " des micro-ondes sur la polymérisation par ouverture de cycles du D,L-lactide a également été démontrée grâce à une investigation systématique. Dans un second temps, l'élaboration de divers matériaux tridimensionnels nanofibreux par électrofilage (" electrospinning ") a été réalisée afin de fabriquer des structures à base de PHAs de différentes morphologies avec la formation de fibres dans une large gamme de diamètres ou encore avec des topographies de surface contrôlées (nanopores ou rainures). Plusieurs stratégies de fonctionnalisation superficielle ont été également mises au point telles que le dépôt de nanoparticules d'hydroxyapatite selon un procédé original couplant les techniques de l' " electrospinning " et de l' " electrospraying ", ou encore le " co-electrospinning " de la gélatine. De nouvelles approches de couplage covalent de molécules en surface des fibres de PHAs par chimie " click " ou par ouverture de fonctions époxyde préalablement introduites ont également été développées. Enfin, des investigations biologiques in vitro ont permis de mettre en lumière les potentialités de ces nouveaux matériaux nanofibreux comme supports de culture cellulaire à travers l'évaluation de l'adhérence, la prolifération et la différentiation de cellules souches mésenchymateuses humaines (hMSCs) pluripotentes vers un phénotype ostéoblastique