Hur kan livscykelanalyser bistå riskvärderingen vid val av åtgärdsmetod? I det här examensarbetet undersöktes hur resultaten från livscykelanalyser kan användas i beslutstödsverktyget SAMLA för förorenade områden för att bistå val av åtgärdsmetod vid Finspångs centraltvätt. Examensarbetet har genomförts i samarbete med Structor Miljö Öst AB. Livscykelanalyser har utförts för två olika typer av åtgärdsmetoder in situ, stimulerad anaerob reduktiv deklorering samt elektrisk konduktiv uppvärmning. Tidigare studier har visat att olika livscykelanalysmetoder ger olika resultat. Även den här studien bekräftar det. Därför bör inte resultat från olika metoder jämföras. Livscykelanalyser kompletterar SAMLA för förorenade områden väl. De procentuella förhållandena beräknades mellan åtgärdsmetodernas miljö- och klimatpåverkan. I värderingssteget i SAMLA bedöms åtgärdsalternativens påverkan i jämförelse med nollalternativet. En bedömning gjordes av respektive åtgärdsalternativ och korrigering av förhållandet mellan metoderna utfördes genom att samma procentuella förhållande som beräknats fram för miljöbelastningen respektive klimatpåverkan beräknades för värderingspoängen. Med stöd av livscykelanalyser samt riskvärdering bör efterbehandlingsmetoden stimulerad anaerob reduktiv deklorering väljas för Finspångs centraltvätt. / How can life cycle analyzes assist the risk assessment when choosing a remediation method? In this thesis, it was investigated how the results from life cycle analyzes can be used in the decision support tool SAMLA for contaminated sites to assist in the choice of remediation method at Finspång's Centraltvätt. The thesis has been carried out in collaboration with Structor Miljö Öst AB. Life cycle analyzes have been performed for two different types of in situ remediation methods, Enhanced Reductive Dechlorination and Electrical Conductive Heating. Previous studies have shown that different life cycle analysis methods lead to different results. This study also confirms this. Therefore, results from different methods should not be compared. Life cycle analyzes complement SAMLA for contaminated sites. The percentage ratios were calculated between the remediation methods' environmental and climate impact. In the valuation step in SAMLA, the impact of the remediation alternatives is assessed in comparison with the no action alternative. An assessment was made of the respectively remediation alternatives and a correction of the relationship between the methods was performed by calculating the same percentage ratio that was calculated for the valuation points of the environmental and climate impact. With the support of the life cycle analysis and the risk assessment the remediation method Enhanced Reductive Dechlorination should be chosen for Finspång's Centraltvätt.

Tesis por compendio / [ES] La funcionalización de tejidos permite dotar a estos de nuevas propiedades que no poseen de forma inherente. Por su parte, el grafeno presenta excelentes características en cuanto a conductividad térmica y eléctrica, resistencia y flexibilidad. En esta tesis se evalúa la aplicación de grafeno sobre diferentes sustratos textiles para obtener tejidos capaces de conducir la electricidad y responder a estímulos térmicos, bien disipando el calor o bien transformando una corriente eléctrica en un incremento de temperatura en su superficie. Para ello, se aplica grafeno empleando diferentes métodos recubrimiento con rasqueta e impregnación sobre tejidos de celulosa y de poliéster. En primer lugar, destaca la influencia que ejerce la estructura del tejido sobre la resistencia eléctrica del recubrimiento, dando como resultado que aquellos tejidos con mayor coeficiente de ligadura son los que mejores resultados presentan al tener una superficie más homogénea en la que se deposita el recubrimiento. Asimismo, se halla que la incorporación de materiales de cambio de fase en el recubrimiento con grafeno permite una mayor disipación de calor cuando se calienta el tejido. Además, se consigue calefactar las muestras empleadas utilizando diferentes voltajes eléctricos lo que, a su vez, sirve para evaluar los defectos del recubrimiento analizando las imágenes termográficas. Entre otros hallazgos relevantes también cabe destacar la influencia que ejerce la humedad del sustrato sobre la resistencia eléctrica del grafeno y la importancia del curado térmico de las resinas para asegurar una buena solidez a los lavados. / [CA] La funcionalización de teixits permet dotar a aquests de noves propietats que no posseeixen de manera inherent. Per part seua, el grafé presenta excel·lents propietats quant a conductivitat tèrmica i elèctrica, resistència i flexibilitat. En aquesta tesi s'avalua l'aplicació de grafé sobre diferents substrats tèxtils per a obtindre teixits capaços de conduir l'electricitat i respondre a estímuls tèrmics, bé dissipant la calor o bé transformant un corrent elèctric en un increment de temperatura en la seua superfície. Per a això, s'aplica grafé emprant recobriment amb rasqueta i estampat sobre teixits de cel·lulosa i de polièster. En primer lloc, destaca la influència que exerceix l'estructura del teixit sobre la resistència elèctrica del recobriment, obtenint que aquells teixits amb major coeficient de lligadura són els que millors resultats presenten en tindre una superfície més homogènia en la qual es deposita el recobriment. Així mateix, es troba que la incorporació de materials de canvi de fase en el recobriment amb grafé permet una major dissipació de calor quan es calfa el teixit. A més, s'aconsegueix calefactar les mostres emprades utilitzant diferents voltatges elèctrics el que, al seu torn, serveix per a avaluar els defectes del recobriment analitzant les imatges termogràfiques. Entre altres troballes rellevants també cal destacar la influència que exerceix la humitat del substrat sobre la resistència del grafé i la importància del curat tèrmic de les resines per a assegurar una bona solidesa a les rentades. / [EN] Fabrics functionalization provides them with new properties that they do not inherently possess. Furthermore, graphene has excellent characteristics in terms of thermal and electrical conductivity, resistance, and flexibility. In this thesis, the application of graphene on different textile substrates is evaluated to obtain fabrics capable of conducting electricity and responding to thermal stimuli, either by dissipating heat or by transforming an electrical current into an increase in surface temperature. For this purpose, graphene is applied using knife-coating and screen-printing on cellulose and polyester fabrics. First of all, it is worth highlighting the influence exerted by the structure of the fabric on the electrical resistance of the coating, obtaining that those fabrics with the highest interlacing coefficient are the ones that present the best results as they have a more homogeneous surface on which the coating is deposited. Also, it is found that the incorporation of phase change materials in the coating containing graphene allows for greater heat dissipation when the fabric is heated. In addition, it is possible to heat the samples using different electrical voltages, which also serves to evaluate the defects of the coating by analyzing the thermographic images. Among other relevant findings, it is also worth highlighting the influence that substrate humidity exerts on the resistance of graphene and the importance of thermal curing of the resins to ensure good washing fastness. / Ruiz Calleja, TR. (2021). Funcionalización de textiles mediante la aplicación de grafeno [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/179634 / Compendio

One interesting approach is the development of conductive polymer composite fibers for innovative textile applications such as in sensors, actuators and electrostatic discharge. In this study, conductive polymer composite fibers were prepared using several different blends containing conductive components: a conjugated polymer (polyaniline-complex) and/or carbon nanotubes. Different factors such as processing parameters, the morphology of the initial blends and the final fibers, fiber draw ratio and material selection were studied separately to characterize their effects on the fiber properties. In binary blends of PP/polyaniline-complex, the processing conditions, the matrix viscosity and the fiber draw ratio had substantial effects on the electrical conductivity of the fibers and linearity of resistance-voltage dependence. These factors were associated with each other to create conductive pathways through maintaining an appropriate balance of fibril formation and breakage along the fiber. The blend morphology was defined as the initial size of the dispersed conductive phase (polyaniline-phase), which depended on the melt blending conditions as well as the PP matrix viscosity. Depending on the initial droplet phase size, an optimum draw ratio was necessary to obtain maximum conductivity by promoting fibril formation (sufficient stress) and preventing fibril breakage (no excess stress) to create continuous pathways of conductive phase. Ternary blend fibers of PP/PA6/polyaniline-complex illustrated at least three-phase morphology with matrix/core-shell dispersed phase style. When ternary fibers were compared to binary fibers, the former could combine better mechanical and electrical properties only at a specific draw ratio; this showed that draw ratio was a more determinant factor for the ternary fibers, as both conductivity and tensile strength depended on the formation of fibrils from the core-shell droplets of the PA6/polyaniline-complex through the polypropylene matrix. The achieved maximum conductivity so far was in the range of 10 S/cm to 10 S/cm, which for different samples were observed at different fiber draw ratios depending on the mixing conditions, the matrix viscosity or whether the fiber was a binary or ternary blend. To improve the properties, PP/polyaniline-complex blends were filled with CNTs. The CNTs and the polyaniline-complex both had an increasing effect on the crystallization temperature and the thermal stability of PP. Furthermore, the maximum conductivity was observed in samples containing both CNTs and polyaniline-complex rather than the PP with either one of the fillers. Although increasing the content of CNTs improved the conductivity in PP/CNT fibers, the ease of melt spinning, diameter uniformity and mechanical properties of fibers were adversely affected. Diameter variation of PP/CNT as-spun fibers was shown to be an indication of hidden melt-drawings that had occurred during the fiber extrusion; this could lead to variations in morphology such as increases in the insulating microcracks and the distance between the conductive agglomerates in the drawn parts of the fiber. Variations in morphology result in variations in the electrical conductivity; consequently, the conductivity of such inhomogeneous fiber is no longer its physical property, as this varies with varying size. / Thesis to be defended in public on Friday, May 20, 2011 at 10.00 at KC-salen, Kemigården 4, Göteborg, for the degree of Doctor of Philosophy.

Des poly(styrène)s (PS) et poly(oxyde d'éthylène)s (PEO) d'architectures ramifiées et des particules semi-conductrices de poly(3,4-ethylènedioxythiophène)s (PEDOT) ont été synthétisés et utilisés comme supports pour le greffage de ferrocènes (Fc) en leur périphérie. Le greffage s’est effectué par cycloaddition de Huisgen dans le cas des PS et par estérification dans le cas des POE et des PEDOT. La mise en évidence d’une possible interaction entre la terminaison azoture des PS et le système catalytique employé pour la polymérisation radicalaire contrôlée a été faite dans ce travail. Les systèmes obtenus ont été caractérisés et testés par voltampérométrie cyclique pour évaluer leurs propriétés dans le stockage d’électrons pour une application de batterie moléculaire. Les groupements ferrocène peuvent être oxydés et réduits de façon réversible sur les PEO-Fc et les PS-Fc. Pour un taux élevé de Fc, un phénomène de transfert de charge entre le cœur PEDOT et les Fc périphériques a été mis en évidence par voltampéromérie cyclique. / Energy storage system have been developed by grafting ferrocene (Fc) moieties on branched or hyperbranched polystyrene (PS) and polyethyleneoxide (PEO), and on semi-conducting poly(3,4-ethylenedioxythiophene) (PEDOT) particles. Huisgen cycloaddition has been used to graft Fc at the periphery of PS stars, leading to PS-Fc. Synthesis of PEO-Fc and PEDOT-Fc has been done by esterification reaction. A possible interaction in between azido moieties and the catalytic system used for controlled radical polymerization of styrene has been evidenced in this study. Performances as molecular batteries of PS-Fc, PEO-Fc and PEDOT-Fc have been assessed by cyclic voltammetry. Fc moieties can be reversibly oxidized and reduced on PS-Fc and POE-Fc. For high ferrocene content, cyclic voltammetry showed the occurence of charge transfer between ferrocenyl groups and oxidized PEDOT core.

In this thesis, the structural, optical, and electrical properties of wurtzite MgxZn1-xO:Al and MgxZn1-xO:Ga thin films have been investigated in dependence on Mg and dopant concentration. Among the transparent conductive oxides (TCOs), ZnO based compounds have gained renewed interest as a transparent electrode for large scale applications such as defroster windows, at panel displays, touch screens, and thin film solar cells due to low material and processing cost, non-toxicity, and suitable physical properties. In general, these applications require transparent electrodes with lowest possible resistivity of rho < 10^-3 Ohmcm and lower [1]. Recently, it has been reported that Ga and Al doped ZnO thin films can be deposited with respective resistivity of 5x10^-5 Ohmcm [2] and 3 x10^-5 Ohmcm [3] which are similar to the data obtained for other practical TCOs, i.e. the resistivity of about 4x 10^-5 Ohmcm for Sn doped In2O3 (ITO) thin films [4]. Moreover, the bandgap of ZnO can be increased by alloying with Mg offering band alignment between transparent electrode and active (or buffer) layer of the device, e.g. Cu(In,Ga)Se2 solar cells [5]. The tunable bandgap of these transparent electrodes can further increase the efficiency of the devices by avoiding energy losses in the interface region of the layers. From this point of view, this work has been aimed to investigate the doping efficiency and limits in transparent conductive (Mg,Zn)O alloys. For this purpose, the samples investigated in this work have been grown by pulsed-laser deposition (PLD) using a novel, continuous composition spread method (CCS). In general, this method allows to grow thin films with lateral composition gradient(s) [6, 7]. All MgxZn1-xO:Al and MgxZn1-xO:Ga thin films have been deposited on 2-inch in diameter glass, c- or r-plane sapphire substrates using threefold segmented PLD targets in order to grow thin films with two perpendicular, lateral composition gradients, i.e. the Mg composition is varied in one direction whereas the Al/Ga concentration is varied in a perpendicular direction [7, 8]. In order to investigate the influence of the temperature, samples grown at different substrate temperatures in the range of 25 to 600 C were investigated. The optical and electrical measurements have been carried out on (5x 5)mm^2 samples that were cut from the CCS wafers along the respective composition gradients, i.e. Mg and Al/Ga contents. Subsequently, physical properties of thin films have been analyzed for a large range of Al/Ga content between 0.5 and 7 at.%, which corresponds to doping concentrations between 2x 10^20 and 3x 10^21 cm^-3, for different Mg contents x(Mg) ranging from 0.01 to 0.1. It has been found that practically the limiting the dopant concentrations is about 2 x10^21 cm^-3. Further, the electrical data suggests, that the compensating intrinsic defect is doubly chargeable hinting to the zinc vacancy (V_Zn) as microscopic origin. Increasing the dopant concentration above 2 x10^21 cm^-3 leads to a degradation of electrical and structural properties [8]. Further, the influence of growth and annealing temperatures on structural, electrical and optical properties of the films has been studied. For that purpose, Al and Ga doped (2.5 at.% = 1x10^21 cm^-3) Mg0.05Zn0.95O thin films have been chosen from CCS samples grown at T_g = (25 - 600) C . For both doping series, the samples grown at higher temperatures exhibit better crystalline quality compared to the samples grown at lower growth temperatures. As a result, samples grown at higher temperatures reveal higher Hall mobility. For the Al-doping series, the highest free charge carrier density of n = 8.2x 10^20 cm^-3 was obtained for an Mg0.05Zn0.95O:Al thin film grown at 200 C, with corresponding Hall mobility of mu = 13.3 cm^2/Vs, a resistivity of rho = 5.7x10^-4 Ohmcm, and optical bandgap of E_g = 3.8 eV. Interestingly, the free charge carrier density of n = (5 - 8) x 10^20 cm^-3 for samples grown with T_g > 300 C is clearly higher than the value of n = 1.25 x 10^20 cm^-3 that was obtained for the high temperature grown sample, i.e. at T_g = 600 C. Furthermore, for all T_g, Al-doped films have a higher doping efficiency than the Ga-doped counterparts. In order to look deeper into the microscopic origin of this behavior, the samples were post-annealed in vacuum at 400 C. Experimental results showed that the free charge carrier density of Al-doped samples first decreased and saturated afterward with increasing annealing time. On the other hand, the free charge carrier density of the Ga-doped samples first slightly increased and saturated with increasing annealing time. For both doping series, the saturation value of n ~ 1 x 10^20 cm^-3 was very close to the data that has been observed for (i) high temperature grown samples and (ii) the solubility limit of Al in ZnO of 0.3 at.% = 1.2x 10^20 cm^-3, that has been determined by Shirouzu et al. for high temperature grown (T_g > 600 C) Al-doped ZnO [9]. Correspondingly, the optical bandgap also changed, i.e. increased (decreased) for Al- (Ga-) doping series, and approached a constant value of 3.5 0 +- 0.1 eV which is explained by generation of acceptor-like compensating defects, and the solubility limit of the dopants. From XRD data, no secondary phases were found for as-grown and post-annealed films. However, the slight improvement of crystalline quality has been observed on post-annealed samples. Further, it has been shown that the growth and annealing temperatures are important as they strongly affect the metastable state of the solid solution that samples grown at low temperature represent. The low solubility limit of the dopants, i.e. 0.3 at.% for Al in ZnO under equilibrium condition, can be increased by preparing samples by non-equilibrium growth techniques [10]. This is also consistent with experimental results of this work that Al- as well as Ga-doped metastable ZnO and (Mg,Zn)O thin films can be prepared with highest possible doping efficiency for the dopant concentration up to 2.5 at.% when growth or annealing temperatures below 400 C are used.

O óxido de índio dopado com estanho é um semicondutor degenerado de alta transparência no espectro visível e alta condutância elétrica. Por suas propriedades, ele é utilizado como eletrodo transparente em diversas aplicações. Algumas destas aplicações exigem que os filmes sejam depositados sobre substratos poliméricos, que degradam em temperaturas acima de 100 °C. Por este motivo, métodos de deposição que utilizam baixas temperaturas são necessários. O objetivo deste trabalho é o desenvolvimento de técnicas de deposição de filmes de óxido de índio dopado com estanho, em baixas temperaturas (< 100 °C), pelo método de magnetron sputtering de rádio fequência. Filmes foram obtidos sobre substratos de silício, vidro e policarbonato, e suas propriedades físicas, elétricas, ópticas, químicas e estruturais foram analisadas por perfilometria, elipsometria, curvas corrente-tensão, prova de quatro pontas, medidas de efeito Hall, difratometria de raios-X e espectrofotometria. Filmes depositados sobre silício e vidro tiveram resistividade elétrica mínima da ordem de 10^-4 Ohm.cm, enquanto a resistividade do filme obtido sobre policarbonato foi da ordem de 10^-3 Ohm.cm. A transmitância óptica média no espectro visível das amostras variou de 66 a 87 %. Do ponto de vista estrutural, as amostras tenderam a apresentar fase amorfa e cristalina, com orientação preferencial ao longo da direção [100]. De modo geral, as amostras obtidas de 75 a 125 W tiveram as melhores propriedades para serem utilizadas em aplicações que exijam eletrodos transparentes, considerando aspectos elétricos e ópticos. / Indium-tin oxide is a degenerate semiconductor that shows high transmittance in the visible region of the spectrum and high electrical conductance. Because of its properties, this material is used as transparent electrode in a wide variety of applications. Some of these applications demand the indium-tin oxide layer to be deposited over polymer substrates, which degrade at temperatures above 100 °C. Because of this degradation problem, deposition methods at low temperatures are needed. The purpose of this work is the development of low temperature (< 100 °C) indium-tin oxide deposition processes by radio frequency magnetron sputtering method. Thin films were deposited over silicon, glass and polycarbonate substrates, and their physical, electrical, optical, chemical and structural properties were analyzed by surface high step meter, ellipsometry, current-voltage curves, four-point probe analysis, Hall effect measurements, X-ray diffractometry and spectrophotometry. Films deposited over silicon and glass substrates showed minimal electrical resistivity in the order of 10^-4 Ohm.cm, while the resistivity of the film obtained over polycarbonate was in the order of 10^-3 Ohm.cm. The average transmittance in the visible spectrum varied over the range 66 to 87 %. According to the structural study, the films present both amorphous and crystalline phases, with crystallites showing preferential orientation along the [100] direction. In general, films deposited with power varying over the range 75 to 125 W showed the best results to be applied as transparent electrodes, considering electrical and optical aspects.

Os principais objetivos deste trabalho são estudar e caracterizar as perdas em acoplamentos magnéticos a ímãs permanentes, quando da existência de uma barreira de material condutor entre seus rotores. Tais perdas são originadas da circulação de correntes parasitas de Foucault na barreira e implicam um torque resistivo ao torque transmitido pelo acoplamento, diminuindo, dessa maneira, a eficácia de sua transmissão. Com este estudo pretendeu-se investigar também a influência desse efeito resistivo na curva característica do acoplamento, ou seja, na curva torque em função do deslocamento angular entre os rotores. A determinação dessa influência da placa condutora no comportamento do acoplamento magnético é de suma importância, uma vez que permite seu correto dimensionamento em aplicações como bombas seladas e agitadores. Para a determinação da influência da barreira, recorreu-se a uma abordagem analítica para o cálculo das perdas geradas pelas correntes parasitas, que são induzidas na placa condutora. Desta forma, foi possível obter o torque resistivo em função dos parâmetros construtivos do acoplamento e da velocidade de rotação. A validação da metodologia empregada será feita pela comparação dos resultados teóricos com os experimentais, através de ensaios num protótipo já construído. / The main objectives of this work are to study and to determine losses in permanent magnet couplings in the presence of a conductive barrier between its rotors. These losses are originated from eddy currents that circulate in the barrier and entail a resistive torque to the torque that is transmitted by the coupling and therefore, reduces the efficiency of its transmission. With this study, it was also intended to investigate such resistive effect influence in the coupling characteristic curve, i.e. in the torque versus angular shift between rotors curve. The determination of the conductive barrier influence on the magnetic coupling behavior is of major importance, since it allows the correct designing in applications as sealed pumps and magnetic stirrers. In order to determine the barrier influence, an analytical approach was used in order to calculate the losses generated by the eddy current circulation, which are induced in the conductive wall. As a result, it was possible to obtain the resistive torque as a function of the magnet coupling geometrical parameters and angular speed. The validation of the employed methodology will be made comparing the theoretical results with the experimental ones, obtained from tests in the existing prototype.

Nesse trabalho é apresentado o estudo de redes neurais artificiais (RNAs) como sistemas de aprendizado, simulação e otimização de processos de deposição de filmes finos poliméricos. Duas técnicas de deposição comumente utilizadas para a fabricação de dispositivos eletrônicos e sensores poliméricos foram escolhidas: i) spin coating ou centrifugação e ii) automontagem. Na primeira técnica, a espessura final dos filmes finos obtidos foi a característica avaliada em função da velocidade de rotação, do tempo de rotação e da concentração da solução polimérica. Como material de deposição, utilizou-se a poli(o-metoxianilina) (POMA). Com a segunda técnica analisou-se a influência sobre a espessura, sobre a condutância elétrica e sobre o espectro de absorção, do número de bicamadas, do tempo de exposição dos filmes a uma solução dopante de ácido clorídrico (HCl) e do pH das mesmas. Os poliíons utilizados nessa técnica foram a polianilina (PAni) e o poli(vinil sulfato de sódio) (PVS). Os filmes obtidos pela segunda técnica de deposição constituem uma classe de sensores capazes de detectar e quantificar concentrações baixas de HCl diluído em água. Os treinamentos e simulações com redes neurais artificiais foram realizados apenas para a espessura dos filmes de POMA e a absorção dos filmes de PAni/PVS. Foram construídas redes neurais artificiais do tipo multilayer perceptron (MLP) utilizando o software MATLAB e o componente Neural Networks Toolbox. A reprodutibilidade e o número de neurônios contidos na camada intermediária foram avaliados. Os resultados mostram que as redes neurais artificiais treinadas fornecem boas respostas simuladas interpolando e extrapolando os valores experimentais utilizados. Como conclusão mostra-se que é possível a utilização dessa ferramenta para auxiliar a engenharia de processos, as técnicas e análises de deposições de filmes finos poliméricos. / In this work it is shown a study of artificial neural networks used as learning and simulating systems to optimize polymeric thin films deposition processes. Two common layer deposition techniques to fabricate polymeric electronic devices and polymeric sensors were chosen: i) spin coating and ii) self-assembly. In the first technique the final thickness of obtained thin films was the analyzed characteristic as a function of spin speed, spin time and solution concentration. For the deposited layers we used poly(o-methoxyaniline) (POMA). In the second technique we analyzed the influence of the number of bilayers, the pH of deposition solutions and the dipping time in the final thickness, electrical resistance and UV-Vis absorption spectra. As polyions, we used polyaniline (PAni) and poly(vinyl sodium sulfate) (PVS). These films could be used as a sensor to detect low concentrations of HCl diluted in water. After obtaining the experimental data we constructed artificial neural networks using multilayer perceptrons (MLP) architecture with MATLAB and its component called Neural Networks Toolbox. The number of neurons in the hidden layer and the reproducibility were analyzed. The results show that the trained artificial neural networks used in this work provide good simulation responses interpolating and extrapolating the experimental data. As a conclusion we show that it is possible to utilize this tool to aid the process engineering and the polymeric thin film deposition techniques and analysis

Identificação de Dispositivos por Radiofrequência, do inglês, Radio Frequency Identification Device (RFID), é uma tecnologia para identificação, rastreamento e gerenciamento de produtos, animais e até mesmo pessoas sem a necessidade de um campo visual. Com o objetivo de alcançar custos menores e a utilização de processos de fabricação menos agressivo ao meio ambiente, tornou-se importante o desenvolvimento de novos tipos de etiquetas (tags). Em vista disso, a fabricação de antenas impressas compactas usando tinta condutiva, representa uma boa opção. O objetivo dessa pesquisa é o projeto e fabricação de antenas impressas sobre substratos flexíveis utilizando tinta condutiva composta de nanopartículas de prata. O desenvolvimento deste tipo de etiquetas é justificado principalmente pelos seguintes motivos. Primeiro, o processo reduz o uso de agentes químicos comumente empregados na fabricação convencional, levando a uma significativa redução no impacto ambiental. Segundo, a fabricação utilizando substratos como, por exemplo, papel ou polímero, reduz substancialmente o custo final da etiqueta. Estudos teóricos e práticos, juntamente com simulações eletromagnéticas foram realizados. Dois processos de prototipagem da etiqueta foram executados: um utilizando uma impressora jato de tinta que funciona propelindo gotas de tinta sobre o substrato e o outro utilizando serigrafia ou silkscreen printing que é muito prático para imprimir formas geométricas através de uma tela de fios trançados. Esses métodos de impressão permitiram a produção rápida da antena sem a necessidade de máscaras de fotolitografia, como é amplamente utilizado na indústria eletrônica. Quatro protótipos foram produzidos e medidas foram realizadas para verificar a viabilidade da utilização dessas etiquetas impressas em relação à sua operação, a confiabilidade das informações armazenadas e a troca de dados com o leitor RFID via interface aérea. Os resultados práticos foram comparados com os obtidos de etiquetas comerciais, onde foi possível verificar que a antena fabricada com tinta condutiva é capaz de capturar e radiar ondas eletromagnéticas de forma eficiente, resultando em uma troca de dados confiáveis através da interface aérea. / Radio Frequency Identification Device (RFID), it is a technology using electromagnetic waves for identifying, tracking and management of products, animals and even people without requiring a visual field. Aiming at achieving low costs and using less aggressive manufacturing processes to the environment, it has become important to develop new types of RFID tags. In view of that, manufacturing compact printed antennas using conductive ink represents a good option. The goal of this research is the design of printed antennas on flexible substrates using silver nanoparticles ink. The developing of this type of tags is justified mainly by the following reasons. First, the process reduces the use of chemical agents commonly employed in conventional manufacturing leading to a significant reduction of the environmental impact. Second, the fabrication using substrates such as paper and polymer foils, substantially reduces the final cost of the tags. Theoretical and practical studies along with electromagnetic simulations were conducted. Two process of RFID prototyping were performed: one using an inkjet printer that operates by propelling particles of conductive ink onto the substrate and another using silkscreen printing that is a very practical method to print geometric forms through a twisted wires screen. These technologies allowed fast production of the antenna without requiring photolithographic masks, as it is widely used in the electronics industry. Four prototypes were produced and measurements were taken to verify the feasibility of using RFID tags printed with conductive ink regarding to its operation, reliability of the stored information and the exchange of data with the RFID reader via air interface. Practical results were compared with those obtained of the commercial tags. It was possible to verify that the antenna manufactured with conductive ink was able to capture and radiate efficiently electromagnetic waves, resulting in reliable exchange of data with the reader through the air interface

O óxido de índio dopado com estanho é um semicondutor degenerado de alta transparência no espectro visível e alta condutância elétrica. Por suas propriedades, ele é utilizado como eletrodo transparente em diversas aplicações. Algumas destas aplicações exigem que os filmes sejam depositados sobre substratos poliméricos, que degradam em temperaturas acima de 100 °C. Por este motivo, métodos de deposição que utilizam baixas temperaturas são necessários. O objetivo deste trabalho é o desenvolvimento de técnicas de deposição de filmes de óxido de índio dopado com estanho, em baixas temperaturas (< 100 °C), pelo método de magnetron sputtering de rádio fequência. Filmes foram obtidos sobre substratos de silício, vidro e policarbonato, e suas propriedades físicas, elétricas, ópticas, químicas e estruturais foram analisadas por perfilometria, elipsometria, curvas corrente-tensão, prova de quatro pontas, medidas de efeito Hall, difratometria de raios-X e espectrofotometria. Filmes depositados sobre silício e vidro tiveram resistividade elétrica mínima da ordem de 10^-4 Ohm.cm, enquanto a resistividade do filme obtido sobre policarbonato foi da ordem de 10^-3 Ohm.cm. A transmitância óptica média no espectro visível das amostras variou de 66 a 87 %. Do ponto de vista estrutural, as amostras tenderam a apresentar fase amorfa e cristalina, com orientação preferencial ao longo da direção [100]. De modo geral, as amostras obtidas de 75 a 125 W tiveram as melhores propriedades para serem utilizadas em aplicações que exijam eletrodos transparentes, considerando aspectos elétricos e ópticos. / Indium-tin oxide is a degenerate semiconductor that shows high transmittance in the visible region of the spectrum and high electrical conductance. Because of its properties, this material is used as transparent electrode in a wide variety of applications. Some of these applications demand the indium-tin oxide layer to be deposited over polymer substrates, which degrade at temperatures above 100 °C. Because of this degradation problem, deposition methods at low temperatures are needed. The purpose of this work is the development of low temperature (< 100 °C) indium-tin oxide deposition processes by radio frequency magnetron sputtering method. Thin films were deposited over silicon, glass and polycarbonate substrates, and their physical, electrical, optical, chemical and structural properties were analyzed by surface high step meter, ellipsometry, current-voltage curves, four-point probe analysis, Hall effect measurements, X-ray diffractometry and spectrophotometry. Films deposited over silicon and glass substrates showed minimal electrical resistivity in the order of 10^-4 Ohm.cm, while the resistivity of the film obtained over polycarbonate was in the order of 10^-3 Ohm.cm. The average transmittance in the visible spectrum varied over the range 66 to 87 %. According to the structural study, the films present both amorphous and crystalline phases, with crystallites showing preferential orientation along the [100] direction. In general, films deposited with power varying over the range 75 to 125 W showed the best results to be applied as transparent electrodes, considering electrical and optical aspects.