Ce travail s’intéresse à la synthèse de films minces composites Zn-Si-O et Ti-Si-O à l’aide d’un procédé hybride combinant le dépôt de silice par PECVD (Plasma Enhanced Chemical Vapour Deposition) à partir du précurseur organométallique hexaméthyldisiloxane (HMDSO-Si2C6H180), et la pulvérisation réactive de zinc ou de titane. L’élaboration de revêtements dont la composition s’échelonne d’un oxyde métallique ZnOx ou TiOx à la silice est rendue possible en agissant sur le débit du précurseur. L’ajout de silicium dans le revêtement fait évoluer sa morphologie de colonnaire à dense. De plus un phénomène de compétition entre les composantes PECVD et pulvérisation du procédé est mis en évidence. Ainsi la mesure des vitesses de dépôt en fonction du débit d’HMDSO permet de déterminer les valeurs de débits critiques de précurseurs à partir desquelles le dépôt de silice par PECVD est initié, et pour lesquelles le recouvrement de la cible par le dépôt de silice se produit. Les caractérisations des revêtements montrent que ceux-ci sont constitués, dans une zone proche de l’interface avec l’acier d’un mélange d’oxydes non stoechiométriques qui diffère de manière importante d’un mélange ZnO+SiO2 ou TiO2+SiO2. Pour les revêtements de type Ti-Si-O le titane est en excès dans la zone proche de l’interface tandis que dans les revêtements de type Zn-Si-O le silicium est en excès. On observe alors une décroissance progressive de la concentration atomique respectivement de titane et de silicium lorsqu’on approche de la surface du revêtement. Ces évolutions peuvent être reliées à un effet de l’augmentation de la température dans la première phase de l’élaboration, qui agit sur la cinétique de dépôt par PECVD et conditionne l’état de contamination de la cible / The present work deals with the synthesis of Zn-Si-O and Ti-Si-O composite thin films by a hybrid process. The coatings are prepared by combining PECVD (Plasma Enhanced Chemical Vapour Deposition) of silicon oxide from hexamethyldisiloxane (HMDSO-Si2C6H180) and reactive sputtering of a zinc or a titanium target. Any composition of the deposited layer can be obtained from zinc oxide or titanium oxide to silicon oxide, by controlling the HMDSO flow rate in the reactor. The morphologies evolve from columnar to dense by adding silicon in the coating. Moreover, a competitive deposition process takes place between PECVD and sputtering. The critical flow rates above which the PECVD silicon oxide deposition takes place on the substrate and on the target can be described from measurements of the thin film deposition rates as a function of the HMDSO flow rate. The coating caracterisations show that they are, near the coating-substrate interface, made of a mixture of non-stoechiometric oxides whose composition is different from a ZnO+SiO2 or a TiO2+SiO2 mixing. Titanium and silicon are in excess near the coating-substrate interface, respectively in the Ti-Si-O and Zn-Si-O thin films. Then the atomic concentrations of titanium and silicon progressively decrease when reaching the surface of the thin film. These behaviours are correlated with an increase of the temperature during the first phase of deposition that increases the PECVD deposition kinetics and determines the contamination state of the target

The thesis deals with the design and subsequent construction of a special hermetic box for the treatment of biological substrates with the help of plasma discharge Gliding Arc. In the theoretical part of the thesis there is a summary of the basic information concerning the design of hermetic box, plasma, hexamethyldisiloxane as a precursor and wood as a lignocellulosic substrate. The experimental part of the thesis is focused on pilot measurements in which specimens were treated plasma and hexamethyldisiloxane. Furthermore, the effect of the treatment on the hydrophobic of the surface was investigated with the drop method. With the help of SEM microscopy was investigated the effect of modification on surface morphology

This work deals generally with surface diagnostic and optical properties of thin layers which are created by plasma polymerization of hexamethyldisiloxane monomer. The influence of oxygen adittion on thin layers properties was studied, too. This polymer layers are commercially made to protect reflective layers in the headlights. Thin layers were made in deposition chamber AluMet 1800V at Zlin Precision Company. Teoretical part of this work deals with methods which are used for deposition of thin layers, mainly physical (PVD) and chemical (PECVD, CVD) depositions. The conditions which influenced plasma polymerization itself are discussed as well as, monomers which are used for plasma polymerization and stability of thin polymer layers. Also there are mentioned the most frequent plasma processes diagnostic methods applicable during the deposition (optical emission spectroscopy) and methods for thin layers diagnostic (wettability, UV-VIS and infrared spectroscopy). Spectrometer Jobin Yvon Triax 320 was used for emission spectra acquisition during the plasma deposition. There were analyzed only two spectra created at same conditions as power at 3 kW and monomer flow rate at 100 sccm; the first one was in pure monomer, the second was obtained with oxygen addition of 150 sccm into the monomer flow. There was not found any essential differences between these spectra in the range 300 nm to 800 nm. Besides the thin layers analyzes after their formation, the samples were exposed to common aging conditions with respect to their use. One third of the prepared samples was exposed by ultraviolet radiation for 48 hours (exposure power of 0.68 W.m-2 at 340 nm) and the other part of samples was inserted for four days into NaCl solution of 50 g.l-1. The surface properties of layers were studied by their contact angle with three liquids (water, diiodmethane, and glycerol) that allowed their surface energy calculation. Results of this measuring are as following: Oxygen addition decreased contact angle of water after exposure of UV radiation. If the highest flow rate of monomer was used and oxygen was added, NaCl degradation did not have any significant influence on contact angle to water. Optical properties of prepared thin films were characterized by UV-VIS spectroscopy. Optical properties were measured only for samples after deposition and samples that were exposed by ultraviolet radiation. Results showed that oxygen addition into the reacting mixture increased the light absorption in UV-VIS (300-800 nm). The absorption was significantly increased after exposure of ultraviolet radiation. With respect to the application of these thin layers is necessary to say that this influence is undesirable. On the other hand, absorption of thin layers deposited at 2 kW, without oxygen addition and flow rate of monomer at 125 sccm a 150 sccm was decreased. Results of this work can be useful for investigation and study of deposited thin layers. The most useful can be with another work which deals with plasma diagnostics during the deposition even more closely. Then it will be possible to adjust and predict properties of deposited layers.

Les travaux présentés dans ce mémoire portent sur l’étude des plasmas d’hélium générés par micro-ondes en cavité résonnante à la pression atmosphérique et sur leurs applications en traitement de surfaces. Tout d’abord, un état de l’art sur les plasmas micro-ondes à la pression atmosphérique et leurs applications est présenté. Ensuite, un modèle collisionnel-radiatif de la décharge et de la post-décharge d’hélium pur est établi. Les résultats du modèle sont comparés aux mesures expérimentales obtenues à 2500 K et un jeu de sections efficaces et de constantes cinétiques valables pour ces conditions est proposé. Expérimentalement, des analyses par spectroscopie d’émission et d’absorption sont employées. La température du gaz est déterminée par la méthode du spectre rotationnel synthétique en fonction de la puissance, de la concentration et de la nature des impuretés introduites dans l’hélium. Il s’avère que le volume du plasma est un paramètre déterminant sur la température du gaz. La concentration du métastable He(23S), en décharge continue et pulsée, est déterminée par absorption laser. En décharge continue, la concentration du métastable est divisée par trois avec 360 ppm d’impureté, la nature de l’impureté n’ayant pas d’importance. En revanche, en post-décharge la nature de l’impureté est déterminante. Les mesures réalisées indiquent que He+ et non He2+ serait l’ion majoritaire. Concernant les applications de ce type de plasma, nous avons travaillé en post-décharge uniquement. Nous avons démontré la faisabilité du procédé de dépôt de SiOx à partir d’hexaméthyldisiloxane. Nous avons aussi montré que la nitruration du titane à haute température était possible / The present work deals with the study of helium microwave plasmas at atmospheric pressure generated in a resonant cavity and their applications in surface treatment. First of all, a state of art of microwave atmospheric pressure plasmas and their applications is presented. Next, a collisional-radiative model for pure helium discharge and post-discharge is described. The results of the model are compared to experimental data obtained at 2500 K and a coherent set of cross-sections and rate constants is obtained for these conditions. Emission and absorption spectroscopy diagnostics are employed to characterize the helium plasma. The gas temperature is determined by the rotational synthetic spectra method. The evolution of the gas temperature, as a function of the input power, the concentration and the nature of impurities in helium, is measured. It turns out that the plasma volume plays a significant role on the gas temperature. The He(23S) concentration is determined by laser absorption in pulsed and continuous mode. In continuous mode, the metastable concentration is divided by 3 with 360 ppm of impurity, regardless of the nature of the impurity. Nevertheless, during the post-discharge, in pulsed mode, the nature of the impurity plays an important role. These measurements support the idea that He+ and not He2+ is the main ion. Concerning the applications, only post-discharges are utilized. We demonstrate that deposition of SiOx using hexamethyldisiloxane as precursor can be efficient. We show that titanium nitriding at high temperature is possible

Thin films have been used to modify surface properties of various materials for many years. Plasma Enhanced Chemical Vapor Deposition (PECVD) is one of the possible methods for their preparation and this technique is applied in this work as well. An organosilicone – hexamethyldisiloxane – is used as precursor. Thin films are created on the surface of the substrate using mixture of precursor and oxygen in radiofrequently excited capacitively coupled plasma. The aim of the thesis is to find the optimal deposition conditions for production of transparent thin layers with good barrier capabilities, low oxygen transmission rate especially. Thin film depositions were realized for different compositions of the deposition mixture in continuous and pulsed mode of plasma with varying supplied power and duty cycle values. The deposition process itself was monitored in situ by optical emission spectroscopy. Thin film coatings were analyzed to determine their physical chemical properties (infrared spectroscopy, surface energy) and barrier properties. Using optical emission spectroscopy, important particles were identified in the deposition plasma. Vibrational, rotational and electron temperatures were determined from relative intensities of chosen fragments. Composition of thin films was studied by infrared spectroscopy. The best results of oxygen transmission rate were achieved with layers prepared from deposition mixture with high oxygen content. It was possible to improve barrier properties by performing deposition in pulsed plasma mode with 20–30% duty cycle. In this diploma thesis, optimal deposition conditions of thin films from hexamethyldisiloxane with low oxygen transmission rate were determined. It is possible to use these results in practical applications, such as corrosion inhibitors for archaeological objects. Optionally, they can be used in various industry branches where it is desirable and feasible to prevent oxygen access to the material by deposition of barrier coatings.

This diploma thesis deals with the ongoing research under the auspices of the Department of Applied Physics and Technics Faculty of Education, University of South Bohemia in České Budějovice, in which the author of the work was actively participated. The thesis is divided into theoretical and experimental part. The theoretical part contains information from natural polymers, especially cellulose, plasma technology and infrared spectrometry. The subject of the experimental part of the thesis is research that deals with the functionalization of cellulose using a microwave plasma discharge on the apparatus CX-22. In the present research was also conducted to process optimization of functionalization with the liquid precursor hexamethyldisiloxane (HMDSO).

Submitted by DIEGO GLAUCO AZARIAS DOS REIS null (diego.dgadr@gmail.com) on 2017-04-19T18:15:44Z No. of bitstreams: 1 Dissertação-Diego_Reis_2017.pdf: 2518961 bytes, checksum: a16c2b4a218332cdf0587afa47cadbff (MD5) / Rejected by Luiz Galeffi (luizgaleffi@gmail.com), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija esta informação e realize uma nova submissão com o arquivo correto. Agradecemos a compreensão. on 2017-04-19T19:55:04Z (GMT) / Submitted by DIEGO GLAUCO AZARIAS REIS (diego.dgadr@gmail.com) on 2017-04-20T13:12:56Z No. of bitstreams: 1 Dissertação-Diego_Reis_2017.pdf: 2653651 bytes, checksum: af70d0852f1dbed4cb80ba89720797f4 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-25T17:14:34Z (GMT) No. of bitstreams: 1 azarias_dga_me_guara.pdf: 2653651 bytes, checksum: af70d0852f1dbed4cb80ba89720797f4 (MD5) / Made available in DSpace on 2017-04-25T17:14:34Z (GMT). No. of bitstreams: 1 azarias_dga_me_guara.pdf: 2653651 bytes, checksum: af70d0852f1dbed4cb80ba89720797f4 (MD5) Previous issue date: 2017-02-20 / O tratamento de materiais utilizando plasma tem sido utilizado amplamente nos dias atuais com o desenvolvimento de novas tecnologias baseadas em descargas elétricas a pressão atmosférica. Dentre os diversos métodos para produzir plasmas nestas condições destaca-se a descarga por microplasmas. No presente trabalho, um novo dispositivo foi desenvolvido e utilizado para deposição de filmes finos. Em estudos de arrasto de vapores no dispositivo foi verificado a relação linear entre a vazão do gás e a massa arrastada. Deposições poliméricas foram obtidas pela mistura de gás argônio com o monômero hexametildissiloxano (HMDSO) em substratos de vidro. A deposição de filmes ocorreu com a vazão de gás entre 0,07 L/min e 0,4 L/min para potências entre 100 mW e 650 mW. Para outras vazões, ocorreu a formação de material sólido em forma de grânulos submilimétricos. A caracterização dos filmes por espectroscopia infravermelha com transformada de Fourier (FTIR) mostrou a presença de grupos moleculares como trimetilsilil Si(CH3)3, siloxano SiOSi e metino CHx. Os testes de adesão realizados no padrão D3359 ASTM com fita Scotch 3M mostraram boa adesão dos filmes aos substratos. Medições de ângulo de contato mostraram a diminuição da hidrofilicidade da superfície dos substratos com valores variando de 40° sem tratamento para quase 90° com o filme fino. Os resultados mostraram que dispositivo desenvolvido foi utilizado com sucesso na deposição em pressão atmosférica de filmes de HMDSO indicando que pode ser empregado também com outros monômeros. / The treatment of materials using plasma has been used widely nowadays with the development of new technologies based on electrical discharges at atmospheric pressure. Among the various methods of producing plasma in these conditions, we gave attention to microplasmas. In this study, a new device was developed and applied to the deposition of polymeric thin films. The dragging of the vapour in the device was investigated for various organic compounds and gas flow rate. It was observed a linear relation between these parameters. The polymeric depositions were obtained with the mixture of argon gas and hexamethyldisiloxane (HMDSO) on glass slides. The thin film deposition occurred with gas flow rate between 0.07 L/min and 0.4 L/min with potencies around 100 mW and 650 mW. The formation of solid submilimeter grains was observed at others gas glow rates. The regular thin films was analysed by Fourier transform infrared spectroscopy (FTIR) and showed the molecular groups of trimethylsilyl Si(CH3)3, siloxane SiOSi and methyne CHx. The films had a good adhesion when subjected to the D3359 ASTM standard test using adhesive tape Scotch 3M. Contact angle characterization has shown a decrease of the hydrophilicity surface property with values changing from 40o without treatment up to 90o with thin film. The results has shown that the developed device was successfully used for deposition of HMDSO films at atmospheric pressure indicating that can be used with other monomers as well.

Orientador: Edison Bittencourt / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-09T14:21:25Z (GMT). No. of bitstreams: 1 GarciaPerez_Tsai_M.pdf: 2963014 bytes, checksum: 30b5a0713b9e84c3712f9092b1cb4fcd (MD5) Previous issue date: 2007 / Resumo: o desenvolvimento de tecnologias limpas e eficientes que permitam substituir os métodos tradicionais de tratamento da superficie de materiais poliméricos e metálicos em busca de adesão entre eles é uma importante área de pesquisa na atualidade. As tecnologias de modificação superficial com uso de plasma e radiação ultravioleta apresentam-se como alternativas aos tratamentos convencionais em razão de sua pouca geração de resíduos, à fácil manipulação e à possibilidade de tratar superficies de diferentes geometrias. O presente trabalho estuda os processos de ativação de camadas de Hexametildisiloxano (HMDSO), com o uso de plasma de Argônio, Hidrogênio a baixa pressão e radiação ultravioleta (UV, UV/fotoiniciador e VUV), a fim de aumentar sua energia de superficie e melhorar, conseqüentemente, suas características adesivas. Para isso, realizou-se.~ a deposição de camadas de Hexametildisiloxano sobre placas de alumínio, por deposição química, em fase vapor assistida por plasma (PEVD), a que se seguiu o processo de ativação. Estudou-se ainda a influência dos parâmetros de deposição, processos a plasma de baixa pressão e radiação ultravioleta na funcionalização da superfície. Obteve-se, como resultado, um importante aumento na energia de superficie das camadas depositadas. Por exemplo: após usar plasma de Hidrogênio, o ângulo de contato obtido foi de 5,4°, que equivale a um aumento de energia superficial de 96,82 mN/m. O uso de radiação UVNUV e UV/fotoiniciador permitiu também mC?dificar a superficie do HMDSO; porém, quando comparado ao tratamento com plasma, o aumento obtido nos valores de energia de superficie foi significativamente menor. A natureZa química das modificações foi analisada por espectroscopia no infravermelho por transformada de Fourier (FTIR). Dentre os resultados mais importantes na análise por FTIR, observou-se que o plasma de Argônio contribui para a reticulação do filme e lidera a incorporação de funcionalidades de -OH, principalmente pelas reações que acontecem posteriormente com o ar. Quando analisadas as mudanças na morfologia da superficie por microscopia eletrônica de varredura (MEV), a análise evidenciou que, no plasma de Argônio, a radiação VUV possui um importante papel na modificação morfológica da camada de HMDSO depositada / Abstract: The development of clean and efficient technologies to replace traditional methods for solid metallic or polymeric surface treatment in processes related to adhesion is a very important area of research. Plasma treatment and ultraviolet radiation are an altemative to accomplish these objectives since they generate very little residues, can be easily manipulated and make possible the treatment of surfaces with different geometries. The activation of Hexamethyldisiloxane (HMDSO) layers with the use of low pressure Argon plasma, low pressure Hydrogen plasma and ultraviolet radiation (UV, UV/photo initiator and VUV) was carried out. The goal was to increase surface energy consequently, improving the adhesive characteristics of these surfaces. The deposition of Hexamethyldisiloxane layers on aluminium plates, in a first step, was achieved by chemical deposition in vapour phase assisted by plasma (PEVD). The activation process with plasma and ultraviolet radiation followed as a second treatment. The influence of operation parameters over the properties of functionalized surfaces treated with plasma and UV radiation were studied. An important increase on the surface energy of deposited layers was observed. For example, the contact angle measured with de-ionized water was reduced to 5,4° when using the Hydrogen plasma treatment. It was equivalent to an increase in surface energy of 96,82 mN/m. The use of UVNUV radiation and UV/photo-initiator also modify . the surface of HMDSO, however, the increase in the surface energy was smaller. than those observed with plasma treatment. The chemical nature of modified surfaces was analyzed by Fourier Transform Infra Red Spectroscopy (FTIR). The Argon plasma contributes to the film reticulation, and leads the incorporation of - OH functionalities, resulting from reactions with air. Scanning Electron Microscopy (SEM) suggest that, inside of Argon plasma, the VUV radiation possess an important role in the morphologic modification of the HMDSO deposited layer / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química