Smooth fluorocarbon plasma polymer films have been for a long time considered for fabrication of hydrophobic and slippery coatings. Interest in fluorocarbon materials was also supported by their excellent self-lubricant, dielectric properties and chemical inertness. This thesis is focused on development of new methods for fabrication of fluorocarbon plasma polymes, which could combine the chemical composition and the physical structure necessary for reaching superhydrophobic character of coatings. Poly(tetrafluoroethylene) was the subject material. RF magnetron sputtering using gas aggregation cluster source was the method adapted to fabricate fluorocarbon nanostructured films with chemical composition close to conventional bulk PTFE, but with high degree of cross- linking and branched structure. A model of growth of such plasma polymer nanostructures was discussed.

Les problématiques liées aux surfaces et interfaces prennent de plus en plus d’importance dans de nombreux secteurs, aussi bien académiques qu’industriels. Dans de nombreuses applications, il n’est parfois pas nécessaire de conférer la réactivité désirée à la totalité du volume du matériau : une surface aux propriétés bien contrôlées peut suffire.Lieu de discontinuité des propriétés d’un matériau, la surface possède un comportement qui lui est propre, généralement apporté par une étape de fonctionnalisation. Dans ce contexte, ce travail de thèse vise à élaborer des surfaces polymères aux propriétés thermoréversibles, de comprendre les mécanismes réactionnels mis en jeu aux interfaces et de proposer de nouvelles surfaces aux pouvoirs adhésifs réversibles.Il existe de nombreuses techniques permettant de modifier la surface des matériaux. La littérature est abondante et variée, on y trouve notamment des techniques visant à introduire des groupements fonctionnels à la surface d’un substrat. Parmi elles, la polymérisation plasma est une technique de dépôt chimique en phase vapeur, sans solvant, permettant le dépôt de films minces de polymères aux propriétés physico-chimiques contrôlées sur une grande variété de matériaux. Le plasma, état très excité de la matière, est généré grâce à un champ électromagnétique. C’est cette technique de fonctionnalisation qui a été choisie dans ce travail de thèse dans le but de déposer un film mince de polymère possédant des propriétés thermoréversibles sur divers substrats.Les propriétés de thermoréversibilité sont apportées grâce à la présence de groupements furanes, capables de réagir avec un diénophile par une réaction de Diels-Alder (DA). Cette réaction, dite « click », entre un diène et un diénophile a été décrite pour la première fois en 1928 par Otto Diels et Kurt Alder, et fut à l’origine de l’obtention de leur Prix Nobel en 1950. Dans la littérature, les études sur la réaction de DA sont majoritairement réalisées en solution voire sur des matériaux massifs. Cette chimie a été beaucoup moins étudiée sur/dans des films minces, où la notion de confinement prend toute son importance. C’est dans ce contexte que se posent ces travaux de thèse.Dans un premier temps, une étude expérimentale approfondie sur la réactivité de DA (étude cinétique et thermodynamique) a été réalisée. Des polymères plasma ayant des propriétés physico-chimiques variées ont été synthétisés et un couple diène/diénophile modèle, le furane présent dans le polymère plasma et l’anhydride maléique en solution, a été choisi. La compréhension de la réactivité interfaciale de DA sur des polymères plasma constitue la première grande partie de cette thèse. Diverses méthodes de caractérisation des propriétés du film mince fonctionnel (spectroscopie infrarouge, spectrométrie photo-électronique X, mesures d’angle de contact, mesures par microbalance à cristal de quartz avec dissipation, microscopie à force atomique et ellipsométrie) ont été utilisées pour confirmer dans un premier temps la faisabilité du procédé de fonctionnalisation basé sur la polymérisation plasma puis de quantifier la réactivité interfaciale de DA. Dans une seconde partie, la méthodologie développée a été élargie à la compréhension de la réactivité interfaciale de DA et rétro-DA mettant en jeu un autre couple diène/diénophile, à savoir le furane (toujours greffé sur le polymère plasma) et le maléimide (en solution). Enfin, le greffage du maléimide sur un substrat a permis de s’interroger sur la faisabilité d’une adhésion covalente réversible, à l’échelle moléculaire mais aussi macroscopique, entre deux substrats solides fonctionnalisés, l’un avec des groupements furanes, l’autre avec des groupements maléimides. [...] / Should we adapt to materials or can we modify materials to obtain what we want and what we need? Since the beginning of humanity, natural materials (stone, wood, etc.) have allowed civilizations to develop. Thanks to the increase of knowledge in the field of materials and to the development of more and more sophisticated fabrication processes, civilizations have also allowed the development of materials such as metal alloys, ceramics and, more recently, synthetic polymers. Since the second-half of the 20th century, researchers and engineers have found interest in responsive materials and particularly responsive polymers, able to adapt to their surrounding environment such as the mostly studied poly(N-isopropylacrylamine). The number of studies to design new smart materials keeps increasing because they play an important role in the development of advanced technologies. Today, we can find smart materials in all areas of activity.According to the targeted application, different stimuli are considered and can be classified amongchemical or physical stimuli.Recently, chemical stimuli have been studied for various applications, such as the elaboration of pH-stimuli responsive materials to control drug delivery and separation processes. The presence of specific molecules, for instance containing polar groups or able to form hydrogen bonds, can also modify the properties of materials and may be used to induce self-healing processes. Biomolecules may also provide chemical signals for the selective conjugation of proteins or sugars. Besides, physical stimuli have also gained interest because they can be remotely applied. Indeed, electro- or magneto-active polymers respond to an applied electric or magnetic field by changing their size or shape for instance. They are used to elaborate sensors, robotic muscles, to store data and in nanomagnetic materials for various biomedical applications. Photo-sensitive polymers can change their physicochemical properties in response to light irradiation at a given wavelength and intensity. The photoresponsive polymers are broadly used in nano- or bio-technology, such as for bio-patterning and photo-triggered drug delivery. Another highly-studied physical stimulus consists in the variation of the environmental temperature. This method is used for drug delivery, in liquid chromatography to vary the power of separation without changing the column and/or the solvent composition or to elaborate self-healing materials (composites) thanks to weak (H-bonds) or covalent interactions forinstance.In the former examples, the whole composition of the system is usually specifically formulated to react to environmental conditions, although many phenomena locally occur at the surface of the material. This strategy is thus economically non-viable because only few percents of the material volume are exploited for their smart properties. Consequently, industrial renewal can be stimulated by the fabrication of stimuli-responsive coatings that could cover any material, preserving the characteristics of the bulk material and limiting the cost of these additional smart properties. [...]

No description available.

Dentre as fibras vegetais estudadas como reforço para produção de compósitos cimentícios, as fibras de coco verde e sisal se destacam por suas características mecânicas de interesse industrial, baixo custo e baixa densidade. O objetivo deste trabalho é o estudo da funcionalização de fibras de coco verde e sisal, pela técnica de polimerização com plasma frio de metano, bem como a análise do efeito do tratamento, a fim de reduzir a hidrofilicidade natural das fibras, preservar suas propriedades mecânicas e aumentar sua durabilidade em meio alcalino. Fibras de coco verde e sisal foram tratadas com plasma frio de metano durante 4, 10 e 20 min. O experimento também incluiu ensaio de degradação das fibras, antes e após tratamento, em solução saturada de cimento Portland. Por meio de análise de molhabilidade e de espectroscopia de fotoelétrons excitados por raios X foi identificado que o tratamento tornou a superfície das fibras de sisal tratadas por 10 e 20 min menos hidrofílica, e das fibras de coco verde tratadas durante o mesmo tempo mais hidrofílica. Corroborando esses resultados, ensaio de arrancamento foi realizado em fibras de sisal tratadas por 20 min indicando boa aderência entre a fibra tratada e a matriz cimentícia. Após ensaio de degradação em solução cimentícia de ambas as fibras tratadas durante 10 e 20 min os resultados da espectroscopia na região do infravermelho por transformada de Fourier indicaram que o tratamento retardou o processo de degradação alcalina da hemicelulose e lignina das fibras de sisal, enquanto que para as fibras de coco verde a degradação das fibras sem tratamento foi igual ao daquelas sem com tratamento. Os ensaios mecânicos indicaram que as fibras de sisal tratadas tiveram maior resistência mecânica quando comparadas àquelas sem tratamento, e com relação às fibras de coco verde não houve diferença significativa entre fibras tratadas e sem tratamento. Além disso, não houve alteração do módulo de elasticidade das fibras de coco verde e sisal (sem tratamento e tratadas). Nesse contexto, os resultados obtidos indicaram que o tratamento com plasma frio de metano é eficaz para redução da hidrofilicidade da superfície das fibras de sisal, podendo vir a ser um tratamento promissor para minimizar a degradação alcalina da hemicelulose e lignina. / Among the studied plant fibres as reinforcement for the production of cement composites, green coconut and sisal fibres stand out for its mechanical characteristics of industrial interest, low cost, and low density. The aim of this work is to study of the plasma functionalization of green coconut and sisal fibres with methane cold plasma, as well as the analysis of the effect of this treatment in order to reduce the hydrophilicity of natural fibres, preserving its mechanical properties and increase its durability in alkaline medium. Green coconut and sisal fibres were treated with methane cold plasma for 4, 10 and 20 min. The experiment also included fibre degradation test before and after treatment in saturated solution of Portland cement. Wettability and XPS analyses indicated that the sisal fibres treated for 10 and 20 min presented surface more hydrophobic than green coconut fibres in the same treatment condition. Pullout test was performed in the sisal fibres treated by 20 min indicating good adherence between treated fibre and cement matrix. Both kinds of fibres were submited to degradation test imersed in the cementitious solution. The FTIR results indicated that the treatment retarded the alkaline degradation of the hemicellulose and lignin from sisal fibres whereas treated green coconut fibres showed the same degradation presented by untreated ones. The mechanical tests showed that the treated sisal fibres had higher mechanical strength compared to those without treatment, and regarding green coconut fibres there was no significant difference between treated and untreated fibres. Furthermore, there was no change in the modulus of elasticity of the green coconut and sisal fibre (treated and untreated). In this context, the results indicated that treatment with cold plasma of methane is effective in reducing the excessive hydrophilicity of the surface of sisal fibres and could be a promising treatment to minimize the alkaline degradation of hemicellulose and lignin.

Dentre as fibras vegetais estudadas como reforço para produção de compósitos cimentícios, as fibras de coco verde e sisal se destacam por suas características mecânicas de interesse industrial, baixo custo e baixa densidade. O objetivo deste trabalho é o estudo da funcionalização de fibras de coco verde e sisal, pela técnica de polimerização com plasma frio de metano, bem como a análise do efeito do tratamento, a fim de reduzir a hidrofilicidade natural das fibras, preservar suas propriedades mecânicas e aumentar sua durabilidade em meio alcalino. Fibras de coco verde e sisal foram tratadas com plasma frio de metano durante 4, 10 e 20 min. O experimento também incluiu ensaio de degradação das fibras, antes e após tratamento, em solução saturada de cimento Portland. Por meio de análise de molhabilidade e de espectroscopia de fotoelétrons excitados por raios X foi identificado que o tratamento tornou a superfície das fibras de sisal tratadas por 10 e 20 min menos hidrofílica, e das fibras de coco verde tratadas durante o mesmo tempo mais hidrofílica. Corroborando esses resultados, ensaio de arrancamento foi realizado em fibras de sisal tratadas por 20 min indicando boa aderência entre a fibra tratada e a matriz cimentícia. Após ensaio de degradação em solução cimentícia de ambas as fibras tratadas durante 10 e 20 min os resultados da espectroscopia na região do infravermelho por transformada de Fourier indicaram que o tratamento retardou o processo de degradação alcalina da hemicelulose e lignina das fibras de sisal, enquanto que para as fibras de coco verde a degradação das fibras sem tratamento foi igual ao daquelas sem com tratamento. Os ensaios mecânicos indicaram que as fibras de sisal tratadas tiveram maior resistência mecânica quando comparadas àquelas sem tratamento, e com relação às fibras de coco verde não houve diferença significativa entre fibras tratadas e sem tratamento. Além disso, não houve alteração do módulo de elasticidade das fibras de coco verde e sisal (sem tratamento e tratadas). Nesse contexto, os resultados obtidos indicaram que o tratamento com plasma frio de metano é eficaz para redução da hidrofilicidade da superfície das fibras de sisal, podendo vir a ser um tratamento promissor para minimizar a degradação alcalina da hemicelulose e lignina. / Among the studied plant fibres as reinforcement for the production of cement composites, green coconut and sisal fibres stand out for its mechanical characteristics of industrial interest, low cost, and low density. The aim of this work is to study of the plasma functionalization of green coconut and sisal fibres with methane cold plasma, as well as the analysis of the effect of this treatment in order to reduce the hydrophilicity of natural fibres, preserving its mechanical properties and increase its durability in alkaline medium. Green coconut and sisal fibres were treated with methane cold plasma for 4, 10 and 20 min. The experiment also included fibre degradation test before and after treatment in saturated solution of Portland cement. Wettability and XPS analyses indicated that the sisal fibres treated for 10 and 20 min presented surface more hydrophobic than green coconut fibres in the same treatment condition. Pullout test was performed in the sisal fibres treated by 20 min indicating good adherence between treated fibre and cement matrix. Both kinds of fibres were submited to degradation test imersed in the cementitious solution. The FTIR results indicated that the treatment retarded the alkaline degradation of the hemicellulose and lignin from sisal fibres whereas treated green coconut fibres showed the same degradation presented by untreated ones. The mechanical tests showed that the treated sisal fibres had higher mechanical strength compared to those without treatment, and regarding green coconut fibres there was no significant difference between treated and untreated fibres. Furthermore, there was no change in the modulus of elasticity of the green coconut and sisal fibre (treated and untreated). In this context, the results indicated that treatment with cold plasma of methane is effective in reducing the excessive hydrophilicity of the surface of sisal fibres and could be a promising treatment to minimize the alkaline degradation of hemicellulose and lignin.

Cette thèse propose tout d’abord une méthode originale, appelée 2 en 1, de construction contrôlée, couche-par-couche, de films de polyélectrolytes, basée sur le dépôt d’un unique complexe polycation-polyanion. Détaillée dans le cas du poly(éthylènedioxythiophène)-poly(styrènesulfonate) PEDOT-PSS, la méthode est ensuite étendue avec le même succès à d’autres complexes (poly(éthylèneimine) branché-poly(4 styrènesulfonate), poly(diallyldiméthylammonium)-poly(4 styrènesulfonate) et poly(allylamonium)-poly(4 styrènesulfonate)).Les films 2 en 1 de PEDOT PSS sont robustes vis-à-vis d’un recuit thermique et possèdent une conductivité électronique indépendante de leur épaisseur. Cette conductivité peut être améliorée en utilisant un composite contenant des nanoparticules d’or Au Np PEDOT PSS. Des superstructures alternant dépôts de PEDOT PSS et de composite ont, en outre, pu être construites.La construction est contrôlée non seulement sur des substrats rigides (verre, wafer de silicium) mais également sur des substrats élastomère de type silicone (polydiméthylsiloxane PDMS). Le traitement du PDMS par polymérisation plasma d’EDOT sous vide permet le dépôt subséquent de films 2 en 1 de PEDOT PSS. Par ailleurs, la pulvérisation cathodique d’or sur le PDMS permet d’obtenir des conducteurs étirables, de surcroît utilisables comme substrats de films 2 en 1 de PEDOT PSS.Enfin, de nouveaux complexes aqueux synthétisés par voie chimique à partir d’EDOT et d’un polysaccharide (sulfate de chondroïtine A) ont conduit à des films présentant une très bonne conduction qui peut être augmentée par inclusion de nanoparticules d’or. Ces nouveaux composés sont porteurs d’un potentiel très prometteur. / This thesis proposes firstly an original method, called 2 in 1 method, for controlled, layer-by-layer, polyelectrolytes film buildup, based on the deposition of a sole polycation-polyanion complex. Detailed on the case of poly(ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), the method was then extended with the same success to other complexes (branched poly(ethyleneimine)-poly(4 styrenesulfonate), poly(diallyldimethylammonium)-poly(4 styrenesulfonate) and poly(allylamonium)-poly(4 styrenesulfonate)).The 2 in 1 PEDOT PSS films are robust regarding thermal annealing and have an electronic conductivity independent of their thickness. This conductivity can be improved by using a composite containing gold nanoparticles Au Np PEDOT PSS. Superstructures alternating PEDOT PSS and composite depositions were also obtained.Film buildup is controlled not only on rigid substrates (glass, silicon wafer) but also on elastomeric substrates of the silicon type (polydimethylsiloxane PDMS). The treatment of PDMS by vacuum plasma enhanced chemical vapor deposition (PECVD) of EDOT allows subsequent deposition of 2 in 1 PEDOT-PSS films. Besides, gold sputter deposition on PDMS reaches stretchable conductors. Gold sputtered PDMS can further act as a substrate for 2 in 1 PEDOT-PSS films.Finally, new aqueous complexes, chemically synthesized from EDOT and a polysaccharide (chondroitin sulfate A), lead to films which exhibit a very good conduction, which can be improved by the inclusion of gold nanoparticles. These new complexes are very promising in the field of conductive biomaterials.

Les infections bactériennes lorsqu’elles se développent à partir d’implants sont très difficiles à traiter, l’issue courante étant un retrait pur et simple de l’implant incriminé. Dans ce cadre, les revêtements des biomatériaux ont un rôle important à jouer pour, d’une part, prévenir l’adhésion bactérienne et d’autre part, éliminer les bactéries présentes. Ces revêtements antibactériens doivent par ailleurs permettre une intégration tissulaire des biomatériaux aux cellules rencontrées sur le site de l’implantation. Dans ce travail une nouvelle famille de revêtements antibactériens a été développée. Ils contiennent et libèrent de manière contrôlée un agent bioactif. Ils sont constitués de multicouches de polymère plasma d'anhydride maléique déposées à la surface de fibres de polypropylène tressées et constituant le matériau à implanter. Entre chaque dépôt de polymère plasma (agissant comme couche barrière), des nanoparticules d'argent sont piégées formant ainsi des réservoirs d’agent antibactérien. En raison des différences de propriétés mécaniques entre les films minces plasma et le substrat massique élastique (i.e. tissu de fibre de polypropylène), la résistance à la traction génère des fissures dans les couches polymère plasma, qui sont utilisées comme canaux de diffusion pour les substances bioactives (dans notre cas les ions argent). Avant étirement, la libération spontanée des ions argent par simple diffusion aux travers des couches barrières peut être contrôlée en jouant sur le taux de réticulation des couches plasma. Au cours de l'étirement, le contrôle réversible de l'ouverture des fissures permet une libération maîtrisée des ions argent. Dans le domaine des textiles et d'autres biomatériaux souples, cette stratégie est prometteuse en raison des contraintes mécaniques qui se produisent naturellement sur le site de l'implantation.L'impact de différents types de procédures de stérilisation couramment utilisés (autoclave et irradiation par faisceau d’électrons) sur les propriétés du matériau développé a également été étudié. En particulier, l’incidence sur la chimie de surface, la dispersion des nanoparticules d'argent et la formation de fissures sous étirement a été regardée. La méthode de stérilisation par faisceau d’électrons permet de conserver les propriétés finales recherchées. Enfin, les propriétés antibactériennes du nouveau matériau ont été étudiées. L'effet du relargage des ions argent sur des bactéries Escherichia coli planctoniques, l'adhésion bactérienne et la formation de biofilm sur le système étiré et non-étiré a été évalué. L’intégrité membranaire des bactéries adhérées et des bactéries dans les biofilms a été suivie au cours de l'étude comme indicateur de l’état physiologique des bactéries. Les résultats ont suggéré que la sensibilité des bactéries aux concentrations faibles d'ions d'argent libérés aboutit à la formation de différents types de structures de biofilms sur les matériaux étudiés. L’ensemble des résultats obtenus donne une base solide pour le développement de matériaux intelligents capables de contrôler la libération du principe actif sur le site de l'infection. Nos résultats montrent qu’une faible dose d’argent peut suffire à contrôler l’infection en agissant sur la structure des biofilms formés. / Despite strict operative procedures to minimize microbial contaminations, bacterial infection of implants significantly raises postoperative complications of surgical procedures. One of the promising approaches is to adjust and control antimicrobial properties of the implant surface. New types of antibacterial coatings prepared via plasma polymer functionalization step have been developed. These coatings contain and release in a control way a bioactive agent. Controlled release was achieved by the fabrication of plasma polymer multilayer systems, which consist of two layers of Maleic Anhydride Plasma Polymer deposited on the surface of Polypropylene made surgical mesh. In between plasma polymer layers, silver nanoparticles are trapped as an antibacterial agent reservoir. Owing to differences between mechanical properties of the plasma-polymer thin films and the elastic bulk substrates, tensile strengths generate cracks within the plasma polymer, which might be used as diffusive channels for bioactive substances, here silver ions. The cracks can be controlled mechanically in a reversible way. The tailoring of the spontaneous release of bioactive agent is achieved by the modification of the second plasma polymer deposition conditions. In addition, during mechanical stimulation of the designed material, control over silver ion release is achieved through an elongation-dependent releasing process allowed by the reversible control of the cracks. In the field of textiles and other soft biomaterials, this strategy is promising due to the mechanical stresses that naturally occur at the implant location. In regard of possible application of the developed system as a future biomaterial, the impact of different types of commonly used sterilization procedures on the properties of developed material was studied. The effects of autoclaving and electron beam sterilization methods on the surface chemistry, the dispersion of embedded silver nanoparticles in the plasma polymer and the cracks formation of the developed material was verified. Results showed the compatibility of the developed system with electron beam sterilization method. The antibacterial properties of the new material have been evaluated. The effect of developed system on planktonic bacteria, bacterial adhesion and biofilm formation on stretched and unstretched system was studied. The membrane integrity of the adhered bacteria and bacteria in biofilms was followed during the study as an indicator of the physiologic state of bacteria. Results suggested that the sensitivity of bacteria to low concentrations of released silver ions resulted in the formation of different types of structures of the biofilms on the studied materials. The results give a strong base on the future of intelligent, silver containing materials that control the release at the site of infection. Our results show that low doses of silver may be sufficient to control infection by acting on the structure of bacterial biofilms.

El treball que es presenta en aquesta tesi pretén contribuir al camp de la ciència de superfícies biològiques, amb el desenvolupament de superfícies adaptades amb cadenes lateral reactives per tal de unir covalentment biomolècul·les d'interès a la superfície.La polimerització assistida per plasma del recobriments actius és un mètode atractiu per tal d'obtenir cadenes laterals reactives, mitjançant pel·lícules nanomètriques amb densitats de grups funcionals adaptats. Sota control de les condicions experimentals, l'estructura del dipòsit polimèric es pot control i les estructures químiques obtingudes poden variar des de xarxes polimèriques altament funcionalitzades amb baixa reticulació fins a xarxes altament reticulades amb baix contingut funcional. La recerca descrita en aquesta tesi tracta de la modificació de superfície de diversos substrats per polimerització de plasma. La part essencial del treball es dirigeix cap al funcionalització amb grups èster de pentafluorofenil a la superfície, durant la polimerització per grafting i polimerització de plasma pulsat de pentafluofenil metacrilat. Aquesta classe de grup làbil és de gran interès per a la seva fàcil reactivitat amb molècules amb mines terminals, com pèptids. Altres monòmers comercials també s'han emprat al començament de l'estudi, com a primera aproximació a les tècniques de plasma. La caracterització d'aquestes superfícies s'ha fet a través de tècniques analítiques com FTIR, XPS, AFM o ToF - SIMS entre d'altres.A més, s'ha dut a terme un estudi per fer a mida el polímer de PFM per a millorar la retenció de la seva estructura, i així com un estudi profund de la seva reactivitat davant de molècules amb amines terminals diferents d'interès, afegint SPR o l'aplicació de sensors microcantiliver a les tècniques de caracterització per aconseguir una millor comprensió de la química i cinètica de la reacció.Sobre el propòsit d'aconseguir superfícies funcionalitzades útils, s'ha realitzat un patterning de les superfícies amb l'ús de màscares per a capa selectiva de les mostres per controlar les àrees modificades. Això s'ha fet per a l'aplicació d'aquesta pel·lícula a dispositius reals, així com a prova de la seva biocompatibilitat per cultiu cel·lular i per assaigs in vivo. / El trabajo que se presenta en esta tesis pretende contribuir al campo de la ciencia de superficies biológicas, con el desarrollo de superficies adaptadas con cadenas lateral reactivas con el fin de unir covalentemente biomoléculas de interés a la superficie.La polimerización asistida por plasma de recubrimientos activos es un método atractivo con el fin de obtener cadenas laterales reactivas, mediante películas nanométricas con densidades de grupos funcionales adaptados. Bajo control de las condiciones experimentales, la estructura del depósito polimérico se puede control y las estructuras químicas obtenidas pueden variar desde redes poliméricas altamente funcionalitzadas con baja reticulación hasta redes altamente reticuladas con bajo contenido funcional.La investigación descrita en esta tesis trata de la modificación de superficie de diversos sustratos por polimerización de plasma. La parte esencial del trabajo se dirige hacia el funcionalización con grupos éster de pentafluorofenilo en la superficie, durante la polimerización por grafting y polimerización de plasma pulsado de pentafluofenilmetacrilato. Esta clase de grupo lábil es de gran interés para su fácil reactividad con moléculas con minas terminales, como péptidos. Otros monómeros comerciales también se han servido al principio del estudio, como primera aproximación a las técnicas de plasma. La caracterización de estas superficies se ha hecho a través de técnicas analíticas como FTIR, XPS, AFM o ToF - SIMS entre otros. Además, se ha llevado a cabo un estudio para hacer a medida el polímero de PFM para mejorar la retención de su estructura, y así como un estudio profundo de su reactividad delante de moléculas con aminas terminales diferentes de interés, añadiendo SPR o la aplicación de sensores microcantiliver a las técnicas de caracterización para conseguir una mejor comprensión de la química y cinética de la reacción.Sobre el propósito de conseguir superficies funcionalizadas útiles, se ha realizado un patterning de las superficies con el uso de máscaras para capa selectiva de las muestras para controlar las áreas modificadas. Eso se ha hecho para la aplicación de esta película en dispositivos reales, así como a prueba de su biocompatibillidad por cultivo celular y para ensayos in vivo. / The work presented in this thesis has the main aim to contribute in the field of biological surface science, by developing tailored surfaces with reactive side chains in order to attach desired biomolecules to the surface by a covalent link. Plasma polymerization of surface active coatings is an attractive method to obtain reactive side chains, by making nanometer thick films of tailored functional group densities. By controlling the experimental conditions, the structure of the polymer deposit can be largely controlled and the chemical structures obtained can range from highly functional polymer networks of low cross link density to polymer networks of low functional group but high cross link densities. The research described in this thesis deals with the surface modification of various substrates by plasma polymerization. The major part of the work is directed towards the funtionalization with pentafluorophenyl ester groups on the surface, through the grafting polymerization and pulsed plasma polymerization of pentafluophenyl methacrylate. This kind of labile group is of high interest for its easy reactivity to amino terminated molecules, such as peptides. Other commercial monomers were also used at the beginning of the study, as a first approach to the plasma techniques. The characterization of these surfaces is done through several analytical techniques as FTIR, XPS, AFM or ToF-SIMS among others. Furthermore, a study for tailoring the PFM polymer for better structure retention and deep study of its reactivity in front of different amino terminated molecules of interest was performed, adding SPR or the implementation of microcantilever sensors to the characterization techniques to achieve a better understanding of the chemistry and kinetic of the reaction, in order to achieve the best peptide binding for reliable well characterized bioactive interface..On the aim of achieving useful functionalized surfaces, a patterning of the surfaces with the use of masks for selective coating of the samples has been performed to control the modified areas. This has been done for application of this film to real devices, as well as to test of its biocompatibility by cell culture and in vivo assays.

La present tesis contribueix a donar una nova visió dins de l'àrea de modificació de superfícies, la qual implica la nanoestructuració de substrats fent servir la tècnica d'auto-assemblatge per a dipositar sobre aquests un polímer conductor mitjançant deposició química en fase vapor per plasma. L'ús de polímers conductors ha despertat un creixent interès en el desenvolupament de sensors químics per a l'anàlisi de gasos en aplicacions d'enginyeria electrònica. La contínua reducció de mida en aquests dispositius ha encoratjat la proposta d'un mètode alternatiu per aconseguir estructures de rang nanomètric, així com per solucionar problemes com la falta d'adherència entre substrat i polímer, disminuir els límits de detecció o escurçar els temps de resposta.En aquesta investigació s'ha treballat amb monocapes amb un grup pirrol terminal per tal de potenciar la nucleació i creixement de pel·lícules de polipirrol polimeritzades mitjançant plasma. A més, les monocapes han aportat millores en l'adhesió interfacial de l'estructura polímer/metall. Així mateix, s'han dopat les pel·lícules primes de polipirrol per tal d'obtenir la seva forma conductora, les propietats elèctriques de les quals permeten utilitzar-ho com a sensor químic. La seva exposició a un vapor comporta canvis en la conductivitat del polímer, a través dels quals es pot identificar i quantificar l'esmentat analit.L'auto-assemblatge i la deposició del polímer són els factors claus en aquesta investigació. Per tant, s'han utilitzat diverses tècniques de caracterització de superfícies com XPS, TOF-SIMS, FT-IR o SEM, per estudiar les seves propietats físiques i químiques. Igualment, l'ús de l'AFM ha estat de gran ajut per investigar el procés de nucleació i la topografia de les pel·lícules. A més, la tècnica de les quatre puntes ha proporcionat una excel·lent eina per realitzar mesures de conductivitat a les pel·lícules primes. Finalment, les pel·lícules polimeritzades per plasma han mostrat una gran sensibilitat al diòxid de carboni, demostrant la seva capacitat per ser utilitzades com a sensors químics. / La presente tesis contribuye a dar una nueva visión dentro del área de modificación de superficies, la cual implica la nanoestructuración de sustratos utilizando la técnica de auto-ensamblado para depositar sobre éstos un polímero conductor mediante deposición química en fase vapor por plasma. El uso de polímeros conductores ha despertado un creciente interés en el desarrollo de sensores químicos para el análisis de gases en aplicaciones de ingeniería electrónica. La continua reducción de tamaño en estos dispositivos ha alentado la propuesta de un método alternativo para conseguir estructuras de rango nanométrico, así como para solucionar problemas tales como la falta de adherencia entre sustrato y polímero, disminuir los límites de detección o acortar los tiempos de respuesta.En esta investigación se ha trabajado con monocapas con un grupo pirrol terminal para potenciar la nucleación y crecimiento de películas de polipirrol polimerizadas mediante plasma. Además, las monocapas han aportado mejoras en la adhesión interfacial de la estructura polímero/metal. Asimismo, se han dopado las películas delgadas de polipirrol para obtener su forma conductora, cuyas propiedades eléctricas permiten utilizarlo como sensor químico. Su exposición a un vapor conlleva cambios en la conductividad del polímero, a través de los cuales se puede identificar y cuantificar dicho analito.El auto-ensamblaje y la deposición del polímero son los factores claves en esta investigación. Por lo tanto, se han utilizado diversas técnicas de caracterización de superficies, como XPS, TOF-SIMS, FT-IR o SEM, para estudiar sus propiedades físicas y químicas. Igualmente, el uso del AFM ha sido de gran valor para investigar el proceso de nucleación y la topografía de las películas. Además, la técnica de las cuatro puntas ha proporcionado una excelente herramienta para realizar medidas de conductividad en películas delgadas. Finalmente, las películas polimerizadas por plasma han mostrado una gran sensibilidad al dióxido de carbono, con lo cual han demostrado su capacidad para ser utilizados como sensores químicos. / This thesis contributes a new insight into surface modification involving substrates nanostructuration by self-assembly to deposit on them a conducting polymer through plasma enhanced chemical vapor deposition. The use of conducting polymers has gained growing interest in the development of chemical sensor arrays for gas analysis in electronic engineering applications. The size reduction in these devices has encouraged the proposal of an alternative method to achieve structures at nanometer range, as well as overcoming problems like lack of adhesion between substrate and polymer, lower limits of detection or shorten response times.The investigation has dealt with the use of pyrrole terminated monolayers to enhance the nucleation and growth of polypyrrole plasma polymerized films. In addition, monolayers provide an improvement in the interfacial adhesion of the polymer/metal structure. Furthermore, polymeric thin films have been doped to obtain the conducting form of polypyrrole, of which electric properties enable to use it as a chemical sensor. Exposure to vapors leads to changes in polymer conductivity, by which analytes can be identified and quantified.Self-assembly and polymer deposition are key factors in this research, as a consequence surface characterization techniques, such as XPS, TOF-SIMS, FT-IR or SEM, have been employed to study their physical and chemical characteristics. Especially interesting have been the use of AFM to investigate the nucleation process and the film topography. Moreover, the four-point probe technique has provided an excellent tool to perform conductivity measurements on thin films. Besides, plasma polymerized films have shown a high sensitivity to carbon dioxide in order to demonstrate their aptitudes to be utilized as a chemical sensor.

Orientador: Julio Roberto Bartoli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T22:28:46Z (GMT). No. of bitstreams: 1 Giacon_VirginiaMansanares_M.pdf: 2837652 bytes, checksum: cc8b7a2c68b1b5f694c6e06c1feb5bfb (MD5) Previous issue date: 2004 / Resumo: Materiais poliméricos são alternativas aos materiais inorgânicos na fabricação de dispositivos ópticos como guias de ondas e fibras ópticas (POF) para transmissão de luz ou sinal. Isso porque, a estrutura molecular dos polímeros pode ser modelada com versatilidade, contribuindo para obter materiais com índices de refração (?) distintos, baixo custo e fácil processamento. Esses dispositivos são constituídos basicamente de um núcleo e uma camada externa, casca ou cladding. Os materiais para casca são usualmente à base de polímeros fluorados. Neste trabalho estudou-se a modificação de superfície de filmes de poli (metacrilato de metila), PMMA, utilizando-se a técnica de Polimerização por Plasma de gás fluorado. Filmes de PMMA com espessuras de 60 µm foram obtidos por spin coating a partir de uma solução de MIBK e Xileno (30% em massa de PMMA). Seguindo dois planejamentos fatoriais, em diferentes condições de pressão (0,5 a 2 torr) e potência (60 a 150 W), os filmes foram expostos ao plasma de CHF3. As superfícies desses filmes foram caracterizadas através de espectroscopia no infravermelho (FTIR/ATR), ângulo de contato de molhamento, microscopia de força atômica (AFM), espectroscopia XPS e análise gravimétrica. A fluoração da superfície dos filmes de PMMA expostos ao plasma foi confirmada por análises de XPS (razão atômica F/C=1,12) e pelo aumento do ângulo de contato de 700(PMMA original) para 100°. O planejamento fatorial mostrou que a pressão é um fator significante (95% confiança) no seu nível mínimo (0,5 torr) para aumentar o ângulo de contato. Análises via FTIR-ATR mostraram alterações nas intensidades de absorção dos grupos C=O e C-O do PMMA, diminuindo significativamente a razão C=O/C-O após o plasma. Análises de AFM mostraram um tolerável aumento da rugosidade da superfície dos filmes após o tratamento. A espessura da camada fluorada, estimada por gravimetria, foi de aproximadamente 0,11 µm. Essa camada deve apresentar um índice de refração menor que o PMMA, inferido pelo alto teor de flúor na superfície dos filmes, determinado pelas análises XPS / Abstract: Polymeric materials are alternative to inorganic materials for production of optical devices as waveguides and optical fibers (POF) for light transmission. This because the molecular structure of polymers can be versatile modeled, giving materials with different refractive indices, low cost and easy processing. These devices are basically consisted by core with an external layer, cladding, of low refractive index (?) allowing light propagation into the core. The cladding materials are usually made of fluorinated polymers. In this work the surface modification of Poly (methylmethacrylate), PMMA, was studied using the plasma polymerization technique. Polymeric films of 60µm thickness were obtained by spin coating using a solution of MIBK and Xylene (30 wt% PMMA). The films were exposed to CHF3 plasma. The processing conditions followed two factorial experimental designs for gas pressure (0.5 - 2 torr) and plasma power (60 - 120 W). The surfaces of the films were characterized using infrared spectroscopy (FTIR/ A TR), contact angle of wetting, atomic force microscopy, XPS spectroscopy and gravimetry. The surface fluorination of PMMA films was confirmed by XPS analysis and also inferred due to the increase on contact angle from 70° (PMMA original) to 100°. The factorial analysis indicated that pressure is a significant factor to increase the contact angle at the lower level 0.5 torr (95% of confidence). FTIR/ATR analysis showed significant alteration on the absorbance intensity of the C=O/C-O groups after plasma. AFM topography analysis showed a tolerable increase on roughness of the surface of plasma exposed films. The thickness of the fluorinated layer was approximately 0.11 µm (estimated by gravimetry). This fluorinated layer should have lower refractive index than the PMMA, due to the high fluorine content on the film surface (F/C ratio), measured by XPS analysis / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química