No description available.

The Hartmann screen test (HST) is a well-known technique that has been used for many years in optical metrology. This thesis describes how the technique has been adapted to create a system for continuous in situ monitoring of the internal stress in thin films during plasma deposition. Stress is almost always present in thin films. Stress can affect the physical properties of film, and also influence phenomena which are important in the technology of thin film manufacture such as adhesion and crystallographic defects. For these reasons, it is very important to control and manage the film stress during manufacture of devices based on thin films. The commonest way to infer stress is to measure the change in substrate curvature that it produces. This is often done by comparison of substrate curvatures before and after deposition with surface profilometry, or interferometry. However, these methods are unsuitable for implementing during film deposition in the vacuum chamber. A novel method for measuring changes in curvature of the thin film substrate in situ has been developed, making use of the HST. An expanded laser beam is passed through a screen containing a number of small apertures, which breaks it up into several rays. After reflecting from the surface of the thin film wafer, the rays are received on an array detector as a spot pattern. Image processing is performed on the recorded spot images to determine the positions of spots accurately. Spot centre positions are recorded at start of deposition as a reference, then their displacement is tracked with time during deposition. The spot deflections are fitted to a theoretical model, in which the change in sample profile is described by a second-order surface. The principal axes of curvature of this surface and their orientation are obtained by a least-squares fitting procedure. From this, the thin film stress can be inferred and monitored in real time. Equipment using this technique has been designed and developed in prototype form for eventual use in the RMIT cathodic arc deposition facility. First experiments with a classic Hartmann screen configuration proved that the technique gave good results, but precision was limited by diffraction and interference effects in the recorded image which made determination of spot centres more difficult. A modified configuration was developed, in which a camera is focused on the Hartmann screen, giving much sharper spot patterns and improved resolution. Tests on the prototype system and comparison with other techniques have shown that it is possible to determine changes in sample curvature with a precision of approximately 0.01 m-1. This corresponds to stress changes of around 0.5 GPa for typical wafer and film thicknesses used in practice. The Hartmann screen test is straightforward to use and to interpret. Image processing and analysis of the recorded spot patterns can be automated and performed continuously in real time during thin film deposition. The system promises to be very useful for monitoring stress and thus controlling the deposition process for improved quality of thin film manufacture.

No description available.

Office waste paper is one of the fastest growing segments of the recycled fiber industry. Toner particles are rigid, insoluble and difficult to disperse and detach from fibers. Therefore papers made from recycled office waste having high toner content will contain noticeable ink particles. This work will consider an alternative way of efficient de-inking using plasma polymers which will not affect the fibers chemically or mechanically. The focus is development and characterization of plasma-deposited films to serve as a barrier film for the adhesion of ink toner to the paper fibers and thereby enhance ink lift off from the fibers. The plasma treated paper is coated with fluorocarbon (PFE) and polyethylene glycol (PFE) films, with constant thickness of PFE and varying the thickness of PEG by 1500, from 1500 to 4500, for the three cases studied (PFE greater than PEG, PFE=PEG, PFE less than PEG). Handsheets were made using virgin fibers to eliminate effects of fillers. Once the sheets were coated and printing performed, they were re-pulped and both the slurry and the de-inking surfactant were placed in a flotation cell. Handsheets were made from the collected foam and stock and were scanned for particle count. The results indicated higher ink loss for the cases with increased thickness of polymer films. A handsheet with a 7500 film (PFE = 3000 and PEG = 4500) showed 61% ink removal compared to 38% for handsheets with no film deposited. There was also less material loss for the cases with higher polymer film thickness.

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.

O objetivo deste estudo foi investigar o efeito de filmes finos depositados por plasma nas propriedades de superfície, ópticas, microbiológicas e mecânicas de materiais restauradores indiretos. Utilizou-se discos de porcelana (PC) (VM9, VITA, Zahnfabrik) e compósitos indiretos (Enamic (EN) e Lava Ultimate (LU) ) (12 x 1,1 mm). Diferentes metodologias de deposição dos filmes foram estabelecidas: polimerização a plasma (PECVD) com 70%HMDSO/30%argônio (PAr); PECVD com 70%HMDSO/30%oxigênio (PO2); implantação iônica e deposição por imersão em plasma usando 70%HMDSO/30%argônio (PIDP). Um grupo sem filme foi usado como grupo controle (CTL) O reator de plasma foi bombeado até 2,0 Pa e HMDSO, oxigênio ou argônio foram admitidos no reator estabelecendo a pressão de 20 e 24 Pa. O plasma foi estabelecido pela aplicação de radiofrequência (13,56 MHz, 50-150 W, 30 ou 10 min) à um porta amostra em um sistema capacitivamente acoplado. A rugosidade e a espessura do filme foram determinadas por perfilometria; a molhabilidade foi medida pelo ângulo de contato. A morfologia foi avaliada utilizando microscopia eletrônica de varredura e de força atômica e a composição química foi investigada por espectroscopia de energia dispersiva (EDS), de fotoelétrons excitados por raios-x (XPS) e espectroscopia de infravermelho com transformada de Fourier. A razão de contraste e diferenças de cor foram estudadas pela espectrofotometria no visível. As propriedades mecânicas e tribológicas dos filmes foram determinadas por nanoindentação e nanoriscos. O crescimento do biofilme foi avaliado por microscopia confocal de varredura a laser. As propriedades mecânicas foram determinadas pela resistência à flexão biaxial e fadiga. Todos os dados foram analisados estatisticamente (?=0,05). A rugosidade não foi alterada para a maioria dos grupos com filme, exceto para PC-PAr (p=0,023) e EN-PIDP (p=0,001), que tiveram uma diminuição e aumento, respectivamente. As espessuras dos filmes foram de 620 nm (PAr), 540 nm (PO2) e 70 nm (PIDP). A molhabilidade para todos os grupos com filmes diminuiu, exceto o grupo LU-PIDP (p<0,001). A análise morfológica demonstrou que os filmes revestiram os substratos uniformemente sem descontinuidades. Os filmes PO2 apresentaram estruturas granulares que se apresentaram em menor tamanho e quantidade para PAr e PIDP. A composição química dos filmes revelou três elementos principais: silício, oxigênio e carbono. PAr apresentou uma composição mais orgânica, enquanto PO2 e PIDP mostraram uma natureza mais inorgânica. A razão de contraste diminuiu apenas em LU-PIDP (p<0.001) e os valores de ?E ficaram abaixo de 3,3 para todos os grupos com filme. As propriedades mecânicas e tribológicas foram alteradas com a presença dos filmes, de acordo com cada substrato. Os filmes PAr demonstraram a menor dureza e o maior coeficiente de atrito. Os filmes PO2 e PIDP apresentaram maior dureza e menor coeficiente de atrito. Os filmes alteraram o biofilme formado e a viabilidade das colônias em parâmetros específicos. Não houve mudança na resistência e probabilidade de falha dos materiais com filmes. Conclui-se que os filmes finos depositados alteraram as propriedades de superfície e a formação do biofilme, mantendo a cor e rugosidade abaixo de valores críticos e não influenciaram na resistência mecânica ou probabilidade de falha dos materiais restauradores. / The aim of this study was to investigate the effect of plasma deposited thin films on surface, optical, microbiological and mechanical properties of indirect restorative materials. A porcelain (VM9, VITA, Zahnfabrik) and indirect composite disks (Enamic, VITA; Lava Ultimate, 3M ESPE), were used (12 x 1.1 mm). Different methodologies of film deposition were established: plasma-enhanced chemical vapor deposition (PECVD) with 70%HMDSO/30%argon (PAr); PECVD with 70%HMDSO/30%oxygen (PO2); plasma immersion ion implantation and deposition using 70%HMDSO/30%argon (PIDP). Samples with no films were used as control group (CTL). The plasma reactor was pumped down to 2.0 Pa and HMDSO, oxygen or argon were admitted to the reactor establishing the pressure of 20 and 24 Pa. The plasma was ignited by the application of radiofrequency power (13.56 MHz, 50-150 W, 30 or 10 min) to the lowermost sample holder of a capacitivelly-coupled system. Surface roughness and film thickness were determined by perfilometry. Wettability was measured with a goniometer. Morphological analysis was evaluated using scanning electron microscopy and atomic force microscopy. Surface chemical composition was investigated by energy-dispersive and x-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Optical properties were studied by contrast ratio and color differences. Mechanical and tribological properties of the coatings were determined by nanoindentation and scratching test. Biofilm growth was evaluated by confocal laser scanning microscopy. Mechanical properties were determined by biaxial flexural strength and fatigue test. Data were analyzed by statistically (alpha=0.05). Surface roughness was not changed for most of groups after film deposition, PC-PAr and EN-PIDP groups, showed a decrease (p=0.023) and an increase (p=0.001), respectively. The films\' thicknesses were 620 nm (PAr), 540 nm (PO2) and 70 nm (PIDP). A decrease in wettability for all film groups was detected, except LU-PIDP (p<0.001). Morphological analysis demonstrated that films coated the substrates uniformly without any discontinuities. For all materials in PO2, granular structures covered the surface. For PAr and PIDP, these structures decreased. The films\' chemical composition revealed three main elements: silicon, oxygen and carbon. PAr presented a more organic behavior. PO2 and PIDP showed an inorganic nature. For contrast ratio there was only a decrease for LU-PIDP (p<0.001) and color differences continued below 3.3. Mechanical and tribological properties were changed with the presence of the coatings, according to each substrate. PAr films demonstrated the lowest hardness and highest friction coefficient. PO2 and PIDP films had higher hardness and lower friction coefficient values. The films, in different parameters, altered biofilm structure and colony viability. There was no change in strength and failure probability for all coated groups. It can be concluded that plasma-deposited thin films altered specific surface characteristics and biofilm growth, maintaining color properties and surface roughness below established thresholds and strength and failure probability didn\'t differ with the presence of the thin films.

The role of a protein-repelling coating is to limit the interaction between a device and its physiological environment. Plasma-polymerized-PEG (pp-PEG) surfaces are of great interest since they are known to avoid protein adsorption. and cell attachment. However, in all the studies previously published in the literature, the PEG coatings have been prepared using low pressure processes. In this thesis, we synthesize biocompatible pp-PEG coatings using atmospheric pressure plasma. Two original methods are developed to obtain these pp-PEG films. 1. Atmospheric pressure plasma liquid deposition (APPLD) consists in the injection of the precursor, tetra(ethylene glycol)dimethylether (tetraglyme), by means of a liquid spray, directly in the post-discharge of an atmospheric argon plasma torch. 2. In atmospheric pressure plasma-enhanced chemical vapor deposition (APPECVD), tetraglyme vapors are brought in the post-discharge trough a heating sprinkler. The chemical composition, as well as the non-fouling properties of the APPLD and APPECVD films, are compared to those of PEG coatings synthesized by conventional low pressure plasma processes. In the first part of the study, the effect of the power on the chemical composition of the films has been investigated by infrared reflection absorption spectroscopy (IRRAS), X-ray photoelectron spectroscopy (XPS) and secondary ions mass spectroscopy (SIMS). The surface analysis reveals that for the APPECVD samples, the fragmentation of the precursor increases as the power of the treatment is increased. In other terms, the lower the plasma power is, the higher the “PEG character” of the resulting films is. Indeed, the C-O component (286.5 eV) of the XPS C 1s peak is decreasing while the hydrocarbon component (285 eV) is increasing as the power of the plasma is increased. The same conclusion can be drawn from the signature ToF-SIMS peaks (m/z = 45 (CH3OCH2+ and +CH2CH2OH), 59 (CH3OCH2CH2+), 103 (CH3(OCH2CH2)2+)) that are decreasing in the case of high power treatments. Accordingly, IRRAS measurements show that the C-O stretching band is decreasing for high power plasma deposition. This is in agreement with the observations made from the analysis of the LP PECVD coatings and from the literature. The films deposited by the APPLD process do not show the same behavior. Indeed, whatever the power injected into the discharge is, we are able to achieve films with a relatively high PEG character (83 %). The second part of this study is dedicated to the evaluation of the non-fouling properties of the coatings by exposing them to proteins (bovine serum albumin and human fibrinogen) and cells (mouse fibroblasts (L929 and MEF)) and controlling the adsorption with XPS (proteins) and SEM (cells). For the APPECVD samples, a low plasma power (30 W) leads to an important reduction of protein adsorption and cell adhesion (over 85%). However, higher-powered treatments tend to reduce the non-fouling ability of the surfaces (around 50% of reduction for a 80 W deposition). The same order of magnitude (over 90% reduction of the adsorption) is obtained for the APPLD surfaces, whatever is the power of the treatment. Those results show an important difference between the two processes in terms of power of the plasma treatment, and a strong relationship between the surface chemistry and the adsorption behavior: the more the PEG character is preserved, the more protein-repellent and cell-repellent is the surface. / Le rôle d’une couche empêchant l’adsorption de protéines est de limiter les interactions entre un implant et le milieu physiologique auquel il est exposé. Les films de poly(éthylène glycol) polymérisés par plasma (pp-PEG) sont d’intérêt majeur car ils sont connus pour empêcher l’adsorption de protéines ainsi que l’attachement cellulaire. Cependant, dans toutes les études publiées précédemment, les couches de type PEG ont été réalisées sous vide. Dans cette thèse de doctorat, nous synthétisons des couches de type pp-PEG biocompatibles par plasmas à pression atmosphérique. A cette fin, deux méthodes originales ont été développées. 1. La première méthode consiste en l’injection du précurseur, le tetra(éthylène glycol) diméthyl éther (tetraglyme), en phase liquide, en nébulisant ce dernier au moyen d’un spray, directement dans la post-décharge d’une torche à plasma atmosphérique fonctionnant à l’argon. En anglais, nous appelons ce procédé « Atmospheric pressure plasma liquid deposition (APPLD) ». 2. Dans la deuxième méthode, appelée en anglais « Atmospheric pressure plasma-enhanced chemical vapor deposition (APPECVD)», le tetraglyme est amené en phase vapeur dans la post-décharge, au moyen d’un diffuseur chauffant. La composition chimique des dépôts de type APPLD et APPECVD, ainsi que leurs propriétés d’anti-adsorption sont évaluées, et comparées aux dépôts pp-PEG obtenus par les méthodes à basse pression conventionnelles. Dans la première partie de cette étude, nous nous focalisons sur la composition chimique des films déposés, et plus particulièrement sur l’influence de la puissance injectée dans le plasma sur cette composition chimique. A cette fin, nous avons fait appel à des techniques d’analyse telles que la spectroscopie de réflexion-absorption infrarouge (IRRAS), la spectroscopie des photoélectrons X (XPS) et la spectrométrie de masse des ions secondaires (SIMS). Il en ressort que les films de type APPECVD perdent progressivement leur « caractère PEG » à mesure que la puissance de la décharge plasma est élevée. Cela serait dû à une plus grande fragmentation du précurseur dans la post-décharge d’un plasma plus énergétique. Cette tendance est cohérente avec ce que nous avons observé pour les dépôts à basse pression ainsi que dans la littérature. Dans le cas des films de type APPLD, un tel comportement n’a pas été mis en évidence : quelle que soit la puissance dissipée dans le plasma, les films présentent un « caractère PEG » relativement élevé. La deuxième partie de cette thèse est dédiée à l’évaluation des propriétés d’anti-adsorption des films synthétisés, en les exposant à des protéines (albumine de sérum bovin et fibrinogène humain) et des cellules (fibroblastes de souris, L929 et MEF). L’adsorption de protéines est contrôlée par XPS tandis que l’attachement cellulaire est contrôlé par imagerie SEM. Pour les échantillons de type APPECVD, un dépôt à faible puissance (30 W) mène à une importante réduction de l’adsorption de protéines et de cellules (> 85%) tandis qu’à de plus hautes puissances (80 W), l’anti-adsorption est sensiblement diminuée (50% de réduction). Dans le cas des dépôts de type APPLD, quelle que soit la puissance du plasma, une forte diminution de l’adsorption de protéines et de cellules est observée (> 90 %). Ces résultats montrent une différence majeure entre les deux procédés quant à l’influence de la puissance du plasma ainsi qu’une forte relation entre la composition chimique de la surface synthétisée et son pouvoir d’anti-adsorption : plus le « caractère PEG » du dépôt est conservé, plus la surface empêchera l’interaction avec les protéines et les cellules.

O objetivo deste estudo foi investigar o efeito de filmes finos depositados por plasma nas propriedades de superfície, ópticas, microbiológicas e mecânicas de materiais restauradores indiretos. Utilizou-se discos de porcelana (PC) (VM9, VITA, Zahnfabrik) e compósitos indiretos (Enamic (EN) e Lava Ultimate (LU) ) (12 x 1,1 mm). Diferentes metodologias de deposição dos filmes foram estabelecidas: polimerização a plasma (PECVD) com 70%HMDSO/30%argônio (PAr); PECVD com 70%HMDSO/30%oxigênio (PO2); implantação iônica e deposição por imersão em plasma usando 70%HMDSO/30%argônio (PIDP). Um grupo sem filme foi usado como grupo controle (CTL) O reator de plasma foi bombeado até 2,0 Pa e HMDSO, oxigênio ou argônio foram admitidos no reator estabelecendo a pressão de 20 e 24 Pa. O plasma foi estabelecido pela aplicação de radiofrequência (13,56 MHz, 50-150 W, 30 ou 10 min) à um porta amostra em um sistema capacitivamente acoplado. A rugosidade e a espessura do filme foram determinadas por perfilometria; a molhabilidade foi medida pelo ângulo de contato. A morfologia foi avaliada utilizando microscopia eletrônica de varredura e de força atômica e a composição química foi investigada por espectroscopia de energia dispersiva (EDS), de fotoelétrons excitados por raios-x (XPS) e espectroscopia de infravermelho com transformada de Fourier. A razão de contraste e diferenças de cor foram estudadas pela espectrofotometria no visível. As propriedades mecânicas e tribológicas dos filmes foram determinadas por nanoindentação e nanoriscos. O crescimento do biofilme foi avaliado por microscopia confocal de varredura a laser. As propriedades mecânicas foram determinadas pela resistência à flexão biaxial e fadiga. Todos os dados foram analisados estatisticamente (?=0,05). A rugosidade não foi alterada para a maioria dos grupos com filme, exceto para PC-PAr (p=0,023) e EN-PIDP (p=0,001), que tiveram uma diminuição e aumento, respectivamente. As espessuras dos filmes foram de 620 nm (PAr), 540 nm (PO2) e 70 nm (PIDP). A molhabilidade para todos os grupos com filmes diminuiu, exceto o grupo LU-PIDP (p<0,001). A análise morfológica demonstrou que os filmes revestiram os substratos uniformemente sem descontinuidades. Os filmes PO2 apresentaram estruturas granulares que se apresentaram em menor tamanho e quantidade para PAr e PIDP. A composição química dos filmes revelou três elementos principais: silício, oxigênio e carbono. PAr apresentou uma composição mais orgânica, enquanto PO2 e PIDP mostraram uma natureza mais inorgânica. A razão de contraste diminuiu apenas em LU-PIDP (p<0.001) e os valores de ?E ficaram abaixo de 3,3 para todos os grupos com filme. As propriedades mecânicas e tribológicas foram alteradas com a presença dos filmes, de acordo com cada substrato. Os filmes PAr demonstraram a menor dureza e o maior coeficiente de atrito. Os filmes PO2 e PIDP apresentaram maior dureza e menor coeficiente de atrito. Os filmes alteraram o biofilme formado e a viabilidade das colônias em parâmetros específicos. Não houve mudança na resistência e probabilidade de falha dos materiais com filmes. Conclui-se que os filmes finos depositados alteraram as propriedades de superfície e a formação do biofilme, mantendo a cor e rugosidade abaixo de valores críticos e não influenciaram na resistência mecânica ou probabilidade de falha dos materiais restauradores. / The aim of this study was to investigate the effect of plasma deposited thin films on surface, optical, microbiological and mechanical properties of indirect restorative materials. A porcelain (VM9, VITA, Zahnfabrik) and indirect composite disks (Enamic, VITA; Lava Ultimate, 3M ESPE), were used (12 x 1.1 mm). Different methodologies of film deposition were established: plasma-enhanced chemical vapor deposition (PECVD) with 70%HMDSO/30%argon (PAr); PECVD with 70%HMDSO/30%oxygen (PO2); plasma immersion ion implantation and deposition using 70%HMDSO/30%argon (PIDP). Samples with no films were used as control group (CTL). The plasma reactor was pumped down to 2.0 Pa and HMDSO, oxygen or argon were admitted to the reactor establishing the pressure of 20 and 24 Pa. The plasma was ignited by the application of radiofrequency power (13.56 MHz, 50-150 W, 30 or 10 min) to the lowermost sample holder of a capacitivelly-coupled system. Surface roughness and film thickness were determined by perfilometry. Wettability was measured with a goniometer. Morphological analysis was evaluated using scanning electron microscopy and atomic force microscopy. Surface chemical composition was investigated by energy-dispersive and x-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Optical properties were studied by contrast ratio and color differences. Mechanical and tribological properties of the coatings were determined by nanoindentation and scratching test. Biofilm growth was evaluated by confocal laser scanning microscopy. Mechanical properties were determined by biaxial flexural strength and fatigue test. Data were analyzed by statistically (alpha=0.05). Surface roughness was not changed for most of groups after film deposition, PC-PAr and EN-PIDP groups, showed a decrease (p=0.023) and an increase (p=0.001), respectively. The films\' thicknesses were 620 nm (PAr), 540 nm (PO2) and 70 nm (PIDP). A decrease in wettability for all film groups was detected, except LU-PIDP (p<0.001). Morphological analysis demonstrated that films coated the substrates uniformly without any discontinuities. For all materials in PO2, granular structures covered the surface. For PAr and PIDP, these structures decreased. The films\' chemical composition revealed three main elements: silicon, oxygen and carbon. PAr presented a more organic behavior. PO2 and PIDP showed an inorganic nature. For contrast ratio there was only a decrease for LU-PIDP (p<0.001) and color differences continued below 3.3. Mechanical and tribological properties were changed with the presence of the coatings, according to each substrate. PAr films demonstrated the lowest hardness and highest friction coefficient. PO2 and PIDP films had higher hardness and lower friction coefficient values. The films, in different parameters, altered biofilm structure and colony viability. There was no change in strength and failure probability for all coated groups. It can be concluded that plasma-deposited thin films altered specific surface characteristics and biofilm growth, maintaining color properties and surface roughness below established thresholds and strength and failure probability didn\'t differ with the presence of the thin films.

L'absorption des biomolécules, en particulier des protéines, sur les implants médicaux joue un rôle important dans le processus d'acceptation de l'implant dans le corps humain. L'activation des surfaces polymères par polymérisation plasma à pression atmosphérique et traitement plasma sont des méthodes utilisées dans les laboratoires des recherches pour modifier la cinétique d'adsorption et la quantité d'adsorbant. Le but de cette thèse est de mieux comprendre les mécanismes d'absorption des molécules biologiques sur des surfaces polymères modifiées par plasma à pression atmosphérique ou par autoassemblage, d'établir les mécanismes à l'interface et aussi d'établir la liaison entre la conformation des molécules adsorbées et les propriétés de biocompatibilité. / The objective of this thesis is to better understand the absorption mechanisms of biological molecules on surfaces obtained in plasma at atmospheric pressure or by self-assembly, to establish mechanisms at the interface and also establish the link between conformation of proteins adsorbed and the properties of biocompatibility.We studied a discharge at atmospheric pressure to obtain thin films of polyethylene glycol (PEG) and polyethylene glycol (PEG) with polystyrene copolymer. The characterization of thin polymer films was made using techniques atomic force microscopy (AFM), scanning electron microscopy (SEM), the contact angle measurements, infrared spectroscopy with Fourier transform (FTIR ) and X-ray photoelectron spectroscopy (XPS). The surfaces were analyzed in terms of biomolecules absorption with atomic force spectroscopy and quartz crystal microbalance.Studies of the ions and amino acids diffusion through functionalized mesoporous structures by low-pressure plasma are presented. After functionalization, we demonstrate the selectivity of the membrane for a particular class of amino acid, those which have a hydrophilic character.The mechanisms of self-assembly and stabilization of the G type molecules inside of the porous silicon are shown. Because the optical properties of these types of surfaces it can be observed the differences in stability of these molecules on the ionic strength of the different ion which form the structures.

Filmes finos depositados por plasma apresentam varias funções, como proteção de superfície e características de adsorção, úteis no desenvolvimento de sensores. Filmes finos a base de hexametildissilazana HMDS, podem dar origem a materiais adsorventes enquanto filmes fluorados, como os obtidos com metil-nonafluoro (iso)butil-éter HFE®, são bons para passivação e proteção de superfícies expostas a soluções ácidas e básicas. Este trabalho teve como objetivo geral a modificação desses filmes finos objetivando a melhoria na detecção de compostos orgânicos voláteis (VOCs) ou umidade. Os filmes tiveram sua superfície modificada por exposição à radiação beta (feixe de elétrons, 2 MeV, 10 nA a 100 nA) e a radiação ultravioleta (UVC) e foram testados em dispositivos miniaturizados. Foram utilizados dois equipamentos de plasma distintos para a produção dos filmes e vários substratos para deposição: lâminas de silício, cristais piezelétricos de quartzo e acrílico, principalmente. Uma série de caracterizações foi providenciada: Perfilometria (determinação de espessura); Elipsometria (medidas do índice de refração); Espectroscopia de Infravermelho e Espectroscopia de Fotoelétrons Por Raios X para análises da estrutura química; Microscopia Óptica e Eletrônica de Varredura para avaliação da resistência à irradiação UVC ou beta; Medidas de ângulo de contato para determinar a hidrofobicidade e a compatibilidade com VOCs; O software Imagej para a determinação e verificação da ocorrência de formação de aglomerados (clusters) e de suas dimensões. A partir dessas análises escolheram-se filmes com baixa incidência de clusters, para testes em dispositivo miniaturizado, e com alta incidência, para testes de detecção de VOCs ou água. Simulação, produção e testes de dispositivos miniaturizados simples e que favorecem a mistura de reagentes através das características de superfície (misturadores passivos) foi efetuada. O dispositivo testado mostrou-se útil em fase liquida para mistura tanto de líquidos miscíveis quanto imiscíveis. Filmes a base de HFE ou HMDS/HFE pode ser usados como camada passivadora, pois são resistentes à radiação beta, ou UVC. Filmes a base de HMDS sofrem reação por exposição à UVC, o que é útil na construção de dispositivos miniaturizados, ou mesmo detecção de água, dependendo do equipamento de plasma utilizado para deposição. / Plasma thin films present several functions, such as surface protection and adsorption, useful on sensor development. Hexamethyldisilazane (HMDS) thin films can produce adsorbent materials useful as sensitive layer whereas fluorinated films, such as methyl nonafluoro(iso)butyl ether HFE®, are quite useful for passivation and surface protection on acid and basic solutions. This work aims the modification of such films for improvement on volatile organic compounds (VOCs) detection or water detection. The surface of such films was modified by exposure to beta (electron beam, 2 MeV, 10 nA to 100 nA) or ultraviolet (UVC) radiation. These films were also tested on miniaturized devices. Two different plasma- equipment were used and the main substrates for deposition were silicon wafer, piezoelectric quartz crystal and acrylics. The characterization procedures used: profilometer (thickness determination), ellipsometer (refractive index measurement); Infrared (FTIR) and x-ray photoelectron spectroscopy for chemical structure analysis; Optical and scanning electron microscopy for evaluation of resistance to exposition to ultraviolet light or beta radiation; contact angle measurements for determination of hydrophobicity and adsorption of VOCs; Imagej software for evaluation of cluster formation and size. Based on such measurements low density cluster films were tested on a miniaturized device and high density cluster films were used for tests of water and VOCs detection. The simulation, production and tests of simple miniaturized structure that favors mixing were carried out. The conception of the manufactured device is based on passive mixers and mixing was improved to miscible and immiscible fluids as well by changing the surfaces properties of plasma deposited thin films. HFE and HMDS/HFE films were useful as passivation layer, being resistant to beta and UVC radiation. HMDS are sensible to UVC, which was used for obtaining the miniaturized device and is useful to improve water detection, depending on plasma equipment utilized for deposition.