Gloves are an important aspect of personal protective equipment. They protect workers from chemical hazards as well as reduce the risk of exposure to infectious material. Chemical resistant gloves are made from a variety of polymer materials such as plastic, rubber, and synthetic rubber, as not one material provides protection against all chemicals. One type of polymer material may adequately protect against a specific chemical, but may not adequately protect against another. Experiments, such as degradation tests, are used to determine which material is most effective for each chemical tested. Current methods of degradation ratings are based on weight change, which can be expensive. The method described in this study provides an inexpensive alternative to gravimetric analysis. This method uses surface area change as a way to determine the degradation of a polymer material. The percent change data were compared between the weight change and the surface area change. The regression line given was Y=0.4841x + 0.0187 and the R2 value was 0.9096. There is a strong correlation (Pearson r = 0.9519; p ≤ 0.05) between percent weight change and percent surface area change. The Change for surface area is about half that of the weight change, which indicates that the surface area method is more sensitive than the gravimetric determination. Using this information, a rating system was developed for determining the degradation of gloves using surface area.

Increasing bandwidth demands for cloud computing and autonomous applications push the need for system scaling instead of transistor scaling as predicted by Moore’s Law. Optoelectronic interconnections have the potential to enable system scaling at higher bandwidth, power efficiency, and lower cost than copper wiring. The objective of this research is to demonstrate polymer-based optical waveguides with integrated optical turning structures in ultra-thin glass interposers, for fiber-to-chip or chip-to-chip optical interconnections. The fundamental material and process challenges associated with achieving this objective are encompassed in: (1) polymer-glass interfaces and adhesion, (2) lithographically-defined polymer waveguides, and (3) integrated turning structures by inclined lithography. Process guidelines for substrate preparation, adhesion enhancement, and lithographic precision of siloxane-based polymer waveguides in glass were established by fundamentally breaking down and optimizing each process step. In addition, a new process was demonstrated to achieve, for the first time, waveguides with integrated turning structures with self-alignment and symmetry in a single exposure. The new process was enabled by fabricating pre-existing, direct-coated, metallic masks before the inclined exposure step. The demonstrated structures were imaged by polished cross-sectioning and Scanning Electronic Microscopy (SEM).

As cargas minerais têm sido utilizadas em misturas com os mais variados tipos de polímeros, misturas estas chamadas compósitos, com a finalidade de barateamento de custos e, mais particularmente, porque agregam melhorias das características físicas e químicas das peças fabricadas. As indústrias químicas fabricantes de polímeros têm procurado desenvolver novos tipos de polímeros. A disputa torna-se acirrada pelo grande mercado consumidor que existe. As empresas tentam, então, atender as mais diversas necessidades de tipos e características físicas e químicas dos materiais e peças fabricados pelas indústrias consumidoras. No Brasil as cargas minerais ainda são utilizadas pelas indústrias, na sua maioria, de forma empírica, em misturas com os polímeros. O entendimento das propriedades intrínsecas das cargas minerais e dos polímeros, da influência da tensão superficial na interação entre eles, o desenvolvimento de novos equipamentos de medida da tensão superficial, o desenvolvimento de agentes de tratamento superficial visando melhorar a compatibilidade de energia entre a carga mineral e o polímero, tudo isso tem contribuído para uma melhor compreensão e previsão das propriedades de compósitos e nanocompósitos. Várias pesquisas têm sido desenvolvidas nesta direção, cujo intuito principal é o de comparar o efeito do uso, em polímeros, de cargas minerais diversas, tratadas e não tratadas superficialmente com agentes químicos como silanos e ácidos graxos. As características físicas e químicas dos produtos destas misturas, como elongamento, tensão de ruptura à flexão, deformações ao calor, etc, são medidas e definidas, constatando-se modificações nestas propriedades quando comparadas com as mesmas propriedades para os polímeros puros. / The mineral fillers have been used in admixtures with a large variety of polymers called composites with the purpose not only of reducing their prices but mainly due to the improvements of their physical and chemical characteristics. The polymer manufacturers have been looking for the development of new types of polymers and composites in a battle driven by the great existing market as well as the consumers needs for products with distinct physical and chemical properties and lower prices. In Brazil the mineral fillers are still mainly used in empirical admixtures with polymers. The understanding of the intrinsic properties of mineral fillers and polymers, the influence of the surface tensions in the mineral/polymer interactions, the development of new equipments for measuring the surface tension, as well as chemical agents to promote the surface compatibility between mineral and polymer, has contributed for a better understanding and foreseeing the properties of composites and nanocomposites. Many researches have been developed under this direction with the goal of comparing the effect of using mineral fillers with and without superficial treatment by by chemical agents in admixed with polymers. The physical and chemical properties of these composites, such as elongation, flexural tensile strength, heating behavior and many others are measured and defined, supporting the properties enhancement when compared with the same properties for the stand alone polymers.

The aim to provide preventive healthcare and high quality medical diagnostics and treatment to an increasingly ageing population caused a rapidly increasing demand for point-of-care diagnostic devices. Disposables have an advantage over re-usable units as cross-contamination is avoided, no cleaning and sterilising of equipment is required and devices can be used out of centralised laboratories. To remain cost-effective, costs for disposables should be kept low. This makes polymer materials an obvious choice. One method for the realisation of fluidic micro devices is the stacking of several layers of microstructured polymer films. Reel-to-reel manufacturing is a promising technique for high-volume manufacturing of disposable polymer bio-analytical devices. Polyethylene terephthalate (PET) and cycloolefin copolymer (COC) were selected as suitable polymer substrate materials and polydimethyl siloxane (PDMS) as membrane layer. Bonding of polymer films with the help of adhesives carries the risk of channel blocking. Despite this drawback, no other method of bonding PDMS to a structural layer could be identified. Bonding with solvents avoids channel blocking issues, but adversely affects biocompatibility. Thermal diffusion processes enable bonding of COC and PET without the use of any auxiliary material. The extensive process times requires for thermal diffusion bonding can be considerably shortened by pre-treating the material with plasma or UV exposure. Welding with the use of a laser energy absorbing dye was demonstrated to be particularly suitable for selective bonding around channels and reservoirs. None of the assessed bonding methods provide a generic solution to all bonding applications. Instead, the selection of an appropriate technique depends on the intended application and the required level of biocompatibility. Since this selection has implications on the feasibility and reliability of microfluidic structures on the device, design rules which ensure design for production have to be established and followed.

Compared with most construction materials, concrete is considered as a brittle material, and its brittleness increases with the compressive strength. For super-high-strength concrete, failure can be sudden, explosive and disastrous. Also the tensile strength is not proportionally increased. Therefore, it is necessary to carry out research on the brittleness of concrete in order to establish parameters for assessing the brittleness, find ways to improve the brittleness and tensile strength, and eventually design and manufacture concrete materials with high strength and low brittleness. In this study, strengthening and toughening effects of polymer materials on the high performance concrete (HPC) were investigated. The HPC was manufactured using ordinary Class 52.5 N Portland cement, silica fume and superplasticizer. The adopted polymers included the styrene-butadiene-rubber (SBR) latex, polyvinylidene chloride (PVDC), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) with contents of 1.5%, 3% and 5% in weight of cement content. The measured material and fracture properties included compressive and tensile strengths, modulus of rupture, Young's modulus, fracture energy, fracture toughness and brittleness. The test results at 28 days indicate that the addition of 1.5% and 3% SBR, PVDC, LLDPE and HDPE into the HPC could largely improve the compressive strength by up to 15.7%, while the addition of 5% SBR, LLDPE and HDPE did not show any enhancement except for 5% PVDC which increased the compressive strength by 10.9%. The tensile strength was considerably increased for all dosages of polymers, with the maximum increases of 72.7% and 83.2% for 3% SBR and 1.5% LLDPE, respectively. The fracture energy were also enhanced by adding 1.5% SBR and all dosages of LLDPE, with a maximum increase of 24.3%, while there were no indications of enhancement for other dosages of polymers. The modulus of rupture, fracture toughness and Young's modulus were not improved for lower dosages of polymers but slightly decreased for higher dosages. The brittleness decreased monotonically with increasing amount of LLDPE, but it increased with increasing amounts of SBR, PVDC and HDPE.

As cargas minerais têm sido utilizadas em misturas com os mais variados tipos de polímeros, misturas estas chamadas compósitos, com a finalidade de barateamento de custos e, mais particularmente, porque agregam melhorias das características físicas e químicas das peças fabricadas. As indústrias químicas fabricantes de polímeros têm procurado desenvolver novos tipos de polímeros. A disputa torna-se acirrada pelo grande mercado consumidor que existe. As empresas tentam, então, atender as mais diversas necessidades de tipos e características físicas e químicas dos materiais e peças fabricados pelas indústrias consumidoras. No Brasil as cargas minerais ainda são utilizadas pelas indústrias, na sua maioria, de forma empírica, em misturas com os polímeros. O entendimento das propriedades intrínsecas das cargas minerais e dos polímeros, da influência da tensão superficial na interação entre eles, o desenvolvimento de novos equipamentos de medida da tensão superficial, o desenvolvimento de agentes de tratamento superficial visando melhorar a compatibilidade de energia entre a carga mineral e o polímero, tudo isso tem contribuído para uma melhor compreensão e previsão das propriedades de compósitos e nanocompósitos. Várias pesquisas têm sido desenvolvidas nesta direção, cujo intuito principal é o de comparar o efeito do uso, em polímeros, de cargas minerais diversas, tratadas e não tratadas superficialmente com agentes químicos como silanos e ácidos graxos. As características físicas e químicas dos produtos destas misturas, como elongamento, tensão de ruptura à flexão, deformações ao calor, etc, são medidas e definidas, constatando-se modificações nestas propriedades quando comparadas com as mesmas propriedades para os polímeros puros. / The mineral fillers have been used in admixtures with a large variety of polymers called composites with the purpose not only of reducing their prices but mainly due to the improvements of their physical and chemical characteristics. The polymer manufacturers have been looking for the development of new types of polymers and composites in a battle driven by the great existing market as well as the consumers needs for products with distinct physical and chemical properties and lower prices. In Brazil the mineral fillers are still mainly used in empirical admixtures with polymers. The understanding of the intrinsic properties of mineral fillers and polymers, the influence of the surface tensions in the mineral/polymer interactions, the development of new equipments for measuring the surface tension, as well as chemical agents to promote the surface compatibility between mineral and polymer, has contributed for a better understanding and foreseeing the properties of composites and nanocomposites. Many researches have been developed under this direction with the goal of comparing the effect of using mineral fillers with and without superficial treatment by by chemical agents in admixed with polymers. The physical and chemical properties of these composites, such as elongation, flexural tensile strength, heating behavior and many others are measured and defined, supporting the properties enhancement when compared with the same properties for the stand alone polymers.

Il est bien connu que la structuration de surface dans la nature est très importante et ses applications très répandues. Des modèles simples, comme les vagues de surface, sont indispensables dans certains processus naturels et peuvent avoir une application directe aux innovations technologiques. Dans cette thèse, j'étudie les nouvelles méthodes de structuration et de processus de formation de structures contrôlées dans des films minces de polymères, en particulier à des températures inférieures à leur transition vitreuse. J'ai trouvé que la surface de polystyrène vitreux peut être reconstruite à température ambiante, par application directe ou indirecte d'un champ électrique, suggérant fortement qu’une couche de mobilité accrue existe à la surface de ce polymère vitreux. De plus grâce à cette thèse, nous présentons une nouvelle méthode pour induire et contrôler des structures submicroniques sur des substrats hydrophobes en une seule étape de traitement simple, basée sur le traitement du substrat avec une solution aqueuse dégazée. Cette nanostructuration est le résultat d'adsorption des espèces chargées proches sur la surface hydrophobe des polymères créant un champ électrique élevé, ce qui, combiné avec la mobilité de la surface du polymère, induit la déformation du substrat polymère. Comme l'étude directe des propriétés spécifiques de cette région, proche de la surface libre de films minces de polymères, est très rare en raison de la limite des techniques expérimentales appropriées, j'ai réalisé une étude approfondie de la relaxation temporelle des surfaces polymères préalablement structurées par les méthodes décrites ci-dessus. / It is well known that the importance and the applications of surface structuration in Nature and in technology are widespread. Simple patterns, such as surface waves, are indispensable in some natural processes and may have direct application to technological innovations. In this thesis I investigate novel methods of structuring and control structure formation process in thin polymer films, particularly at temperatures lower than their glass transition. We have found that the surface of glassy polystyrene can be reconstructed at room temperature either by direct or indirect application of an electric field, strongly suggesting that a layer of enhanced mobility indeed exists at the surface of this glassy polymer. Additionally through this thesis we present a novel developed way to induce and control submicron structures on hydrophobic substrates by a single, simple treatment step based on treating the substrate with degassed aqueous solution. This nanostructuration is the result of close adsorption of charged species on the hydrophobic polymeric surface building a high electric field, which, combined with the mobility of the polymer surface, induces the deformation of the polymer substrate. Since, the direct study of properties of this specific near free surface region of thin polymer films is very rare due to the limited suitable experimental techniques; we have completed an extensive study of influence of supporting substrate and the temporal relaxation of previously polymer structured surfaces by above described methods.

<p dir="ltr">Nonconjugated radical polymers and small molecules are employed as electrically conducting materials in multiple organic electronic devices, including electrolyte-supported devices and solid-state electronic devices, because of their charge transport and redox-active properties. In fact, macromolecules with nonconjugated backbones and stable radical pendent groups can have impressive charge transport capabilities (i.e., thin-film conductivities of ~20 S m^-1) if proper molecular design principles are employed.</p><p dir="ltr">In the first part of this work, a polysiloxane-based polymer bearing galvinoxyl radical groups has been synthesized. Density functional theory (DFT) calculations predicted that the spin delocalization behavior of the galvinoxyl group would result in a higher charge transfer rate compared with nitroxide radical systems. It is determined that the flexible backbone endowed the polymer with a glass transition temperature around 0 ℃, and this feature allowed the radical moieties to pack into conductive domains after thermal annealing. Furthermore, the conductivity of this radical polymer was quantified to be ~ 10^-1 S m^-1 after being cast into a thin film. Thus, these studies provide a strategy to direct molecular packing and facilitate charge transport in radical polymers with delocalized open-shell sites, which can aid in deciphering the charge transport mechanism in radical polymer thin films.</p><p dir="ltr">In the second part of this work, the charge transport and the magnetic properties of several nitroxide radical-based small molecules have been studied because 1) despite the success of nonconjugated radical polymers as solid-state charge conductors, the charge transport properties of nonconjugated open-shell small molecules have received less attention despite the fact that studying small molecule systems can facilitate the development of macromolecular radical conductors; 2) the unpaired electrons on these materials provide a means by which to respond to magnetic fields, making these materials promising candidates for organic magnets. Motivated by the need to develop open-shell small molecule materials, we quantify the electrical conductivity and magnetic properties in organic radical single crystals. Through proper molecular engineering of functional groups, we synthesized and crystallized a nitroxide radical-based material that has a single-crystal electrical conductivity of ~3 S m^-1, which is the highest values over 1 µm-scale for nonconjugated organic materials reported to date. Furthermore, we manipulate the molecular packing of the nitroxide radical molecules in the single crystals by introducing alkyl chains to the molecular structures. As a result, a strong antiferromagnetic ordering is obtained in the crystals with a Néel temperature of 40 K. In conclusion, new open-shell materials are developed with excellent charge transport capabilities and strong magnetic properties. This effort provides clear insights into designing the next-generation organic radical electrical conductors and magnetic materials.</p>

Ces travaux de thèse se positionnent au cœur des problématiques du patrimoine et notamment de la conservation préventive des œuvres d'art. Pour apporter aux musées une solution à faible coût capable de répondre aux exigences fixées dans le cadre de la protection du patrimoine culturel, nous avons développé de nouveaux vitrages polymères permettant de protéger les œuvres sans en altérer leur perception par le public. Ces matériaux pourront, à terme, tenter de remplacer les vitrages de type poly(méthacrylate de méthyle) (PMMA), très largement utilisés, mais dont le principal inconvénient est sa grande sensibilité à la rayure et aux solvants de nettoyage.Ces matériaux ont été synthétisés en combinant, en différentes proportions, deux polymères, le PMMA et le polycarbonate de CR39® (PCR39®) dans une architecture de réseaux interpénétrés de polymères (RIP). Cette association a permis d'obtenir des nouveaux matériaux transparents (T%>95%) dont la résistance à la rayure et aux solvants est considérablement améliorée comparativement à celle du PMMA. Leurs vieillissements lors de leur exposition à la lumière (UV) artificielle ou naturelle ont été étudiés. Afin d'améliorer leurs propriétés d'anti-rayure, nous avons réticulé sélectivement la phase PMMA avec des nanoparticules de silice fonctionnalisées, ce qui conduit à la réalisation d'un nouveau RIP hybride. Enfin, dans l'optique d'obtenir un matériau intelligent, nous avons étudié la possibilité d'intégrer au sein même de ces vitrages, un capteur de rayonnements UV afin de pouvoir alerter de leur présence. Le PCR39® ayant les propriétés en adéquation avec le développement d'un tel capteur, nous avons ensuite cherché à augmenter la sensibilité du matériau. Pour cela, des composés fluorescents, organique, d'une part et inorganiques d'autre part (nanoparticules d'oxyde de gadolinium dopées soit au terbium soit à l'europium) ont été intégrés au sein des RIP. / This work position itself on a primary issue of heritage and more precisely on the preventive conservation of artworks. To provide a low cost solution to museums, capable of meeting the requirements set for the cultural heritage protection, we have developed new polymer glazing to protect works without altering their perception by the public. These materials will eventually be able to replace poly(methyl methacrylate) (PMMA) glazing, which are widely used but have high sensitivity to scratching and cleaning solvents as mains drawbacks.These materials were synthesized by combining, with various proportions, two polymers, PMMA and polycarbonate of CR39® (PCR39®), into an interpenetrating polymer network (IPN) architecture. This association generated new transparent materials (T% > 95%) of which resistance toward scratching and solvents is considerably improved compared to PMMA's one. Their ageing have been studied when exposed to artificial or natural light (UV). To improve their scratch resistance, we selectively crosslinked the PMMA phase with functionalized silica nanoparticles, leading to the formation of a new hybrid IPN. Finally, in order to obtain a smart material, we studied the possibility of integrating within these glazing, a UV sensor to warn of their presence. The PCR39® having properties consistent with the development of such a sensor, we tried to increase the sensitivity of the material. For that purpose, first an organic fluorescent compounds, and secondly an inorganic one (gadolinium oxide nanoparticles doped with terbium or europium) were incorporated in the IPN.

Supercapacitors are well known for their improvised power density compared to batteries. Ongoing research is mainly focused on improving the energy density of supercapacitors by using different electrode material nanocomposites. The recent research has revealed that graphene (G)-polyaniline (PANI) nanocomposite could be a promising material for supercapacitor applications. The supercapacitor is also associated with self-leakage current regardless of any electrode material. The main objectives of the project are to: (i) synthesize highly fabricate supercapacitor based of G-PANI electrode; (ii) improve the energy density of supercapacitor by applying ultrathin monolayer/monolayers film electrode surface. It is crucial to either improve or retain the effective capacitance of the dielectric film. The dielectric material chosen is polyvinylidene fluoride (PVDF) due to its dielectric constant and electrochemical properties. Langmuir-Schaefer (LS) technique is used to deposit the PVDF film onto the substrate. The optical properties of electrode materials were measured by UV-vis spectrophotometer. The surface morphology of the fabricated electrode material has been investigated using scanning electron microscopic (SEM) and atomic force microscopic (AFM) studies. The supercapacitor with and without dielectric layer have been studied using cyclic voltammetry, charging and discharging, and electrochemical impedance techniques, respectively. The specific capacitance has been found to increase by application of one monolayer of PVDF film of G-PANI electrode. However, the LS film of PVDF does not show the minimization of leakage current but revealed an increase in the specific capacitance due to enhancement in surface area associated with the electrode besides PVDF is also an electrochemical active material. The electrochemical investigation of various layers of PVDF on G-PANI in symmetric and asymmetric supercapacitor configuration has been presented in thesis. The future scope of the project could be designing the electrode with various number of layers of dielectric material that could reduce the leakage current, and retaining the specific capacitance of G-PANI nanocomposite electrodes.