Lithium Air (Li/O2) batteries are energy conversion devices that produce electricity from the oxidation of lithium metal at the anode and the reduction of molecular oxygen at the cathode. These batteries are considered as promising rechargeable cells for high power applications due to their high power density ranging from 1000 to 2000 Wh/kg. However, one of the most significant challenges is the need to separate the metallic lithium anode from any oxygen or water-containing environment while at the same time allowing fast and efficient lithium ion transport through the electrolyte. Therefore, lithium ion conducting materials that are water and CO2 resistant are a prerequisite. Common materials used as anode protective films and/or Li+ conducting electrolytes for lithium air batteries are perovskite-type oxides (formula: ABO3). Perovskites are good candidates for this application because of their versatility, particularly in regards to ionic conductivity. In the present work, a low cost perovskite family such as SFO (SmFeO3) is developed as a lithium ion conducting material by the introduction of Li+ into its lattice. The perovskites have been synthesized using a solid-state reaction method (SSR) and characterized using different techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray Spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). The synthesized perovskites are based on samarium lithium ferrite and divided into two groups depending on the formal presence of vacancies in the stoichiometric formula. The first group (SLFO) with no formal vacancies has the stoichiometric formula of SmxLi1-xFeO2+x (where x = 0.1, 0.2, 0.3, 0.5 and 0.7). While the second group (SLFO*) was generated with less metal atoms than specified in the perovskite structure, thereby generating a structure with intrinsic vacancies and with the formula, Sm(x)Li([1-x] – [0.1] or [0.2]) FeO3-δ (where x = 0.3, 0.4, 0.5 and 0.6). Finally, the effect of varying Li and Sm concentrations in both groups and vacancies created in the lattice for the second group, on the ionic conductivity is explored.

Il existe un réel besoin de développer des matériaux et des technologies avancés pour améliorer l’interface avec le cerveau humain. De tels enregistrements électrophysiologiques sont nécessaires pour des fins diagnostiques ou dans des domaines innovants tels que l’interface homme/machine. Les dispositifs issus de l’électronique organique représentent des alternatives prometteuses grâce à leurs propriétés mécaniques et leur biocompatibilité. L’utilisation de polymères conducteurs ouvre la voie vers une nouvelle interface avec le milieu biologique. Ce travail présente un procédé de fabrication innovant permettant d’intégrer le polymère conducteur PEDOT:PSS sur des électrodes sèches pour une application à l’électroencéphalographie (EEG). L’étape suivante consiste en l’utilisation d’un dispositif actif tel que le transistor organique électrochimique (OECT) afin de profiter de l’amplification locale qu’il permet. Cette dernière est extrêmement importante dans le cas de la neurophysiologie, domaine dans lequel l’amplitude des signaux enregistrés est très basse. En ce sens, l’intégration d’OECTs à des dispositifs d’enregistrement de signaux neuronaux a montré un bien supérieur rapport signal / bruit (SNR) en comparaison à des électrodes conventionnelles. La bioélectronique est un domaine innovant à applications variées. Cette thèse présente la conception et la validation par l’application de dispositifs organiques dans le domaine des neurosciences. D’autres progrès dans les domaines du diagnostic, des biocapteurs, ou de la distribution de médicaments pavent la voie pour de nouvelles applications dans l’agroalimentaire ou encore la qualité de l’eau ou de l’air. / There is a tremendous need for developing advanced materials technologies for interfacing with brain and record neural activity. Such electrophysiological recordings are necessary for diagnostic purposes and brain/machine interfaces. Among the existing technologies, organic electronic devices constitute a promising candidate because of their mechanical flexibility and biocompatibility. The use of conducting polymers, which allow both ionic and electronic transport, allows new modes for interfacing with the biological milieu. This work presents an innovative process to incorporate the conducting polymer poly(3,4-Ethylenedioxythiophene: poly(styrene sulfonate) (PEDOT:PSS) onto electrodes for applications in electroencephalography (EEG). A step beyond conducting polymer electrodes is provided by the Organic Electrochemical Transistor (OECT). The primary advantage of using active devices is the local amplification they provide. This local amplification becomes extremely important in the case of electrophysiological signals, for which the amplitude is very low. The use of the OECT for various electrophysiological measurements is presented, done for clinical purposes like ECG or EEG, for new marketing studies like EOG, and for more fundamental neurological applications, like the recording in vitro of neuronal unitary activity. Bioelectronics is an inspiring field with broad scope. This thesis deals with applications of organic electronic devices in neuroscience. Other applications in diagnostics, biosensing, or drug delivery will offer huge opportunities for food safety, pollution control or even environmental applications.

Atualmente a fabricação de sensores poliméricos tem sido de grande interesse tecnológico e científico, devido à grande demanda por sensores de diversos tipos em inúmeras aplicações. Nesse contexto, a Embrapa Instrumentação Agropecuária tem buscado o desenvolvimento de novas tecnologias, instrumentação, e sensores; visando a preservação do meio ambiente, tema de grande importância mundial. Muitos produtos comercializados nos países em desenvolvimento não atendem ao padrão de qualidade FAO, e o seu mau uso leva a riscos de contaminação de solos, águas de rios, mananciais, e lençóis freáticos; prejudicando a vida aquática, e consequentemente a vida humana. Este trabalho teve um caráter exploratório, e os objetivos foram a preparação, caracterização e desenvolvimento de unidades sensoriais à base de polímeros, com o intuito de avaliar a qualidade da água através da detecção de vários pesticidas. Utilizou-se uma \"língua eletrônica\" constituída por diferentes unidades sensoriais, nas quais foram depositados filmes de polímeros condutores com composições selecionadas e otimizadas a fim de se obter respostas elétricas características para cada tipo de pesticida. Para tanto: i) sintetizou-se quimicamente os polímeros polianilina e poli(oetoxianilina) e caracterizou-se os mesmos; ii) depositou-se (através de automontagem) filmes ultrafinos dos polímeros condutores poli(o-etoxianilina), polianilina e poli(3,4-etilenodioxitiofeno) sobre microeletrodos interdigitados. Estes filmes foram investigados quanto à sensibilidade frente aos pesticidas; iii) Caracterizou-se espectroscopicamente por técnicas de ultra-violeta visível (UVVIS), e microscopicamente (MEV) os filmes e as interações entre os pesticidas e os polímeros; iv) Caracterizou-se o conjunto de unidades sensoriais através de medidas elétricas de capacitância em corrente alternada através de espectroscopia de impedância e análise estatística de Componentes Principais (PCA). Resultados bastante interessantes foram obtidos, e a \"língua eletrônica\" foi capaz de distinguir águas contaminadas com 1 µ mL-1 de pesticidas, de águas não contaminadas / Nowadays the manufacturing of polimeric sensors has been attractingv technological and cientific interests, due to the demand for different sensors in a large number of applications. In this context. Embrapa Agriculturial Instrumentation rias been looking for the development of new technologies, instrumentation and sensor, envisaging environment monitoring, theme of huge global importance. Many products that are in the market in developing countries do not follow the FAO quality standards and their use can cause risks of contamination to soil and water, damaging the acquatic life and consequently the human life. The aim of this project was the preparation. characterization and development of sensing units made by thin layers of conducting polymers, in order to evaluate the water quality mainly due to contamination of pesticides. To achieve these aims, we made use of an \"electronic tongue\" designed with different sensing units in which conductor polymeric films with specific compositions were deposited, in order to have electric responses for each type of pesticide. For that, the following studies were carried out: i) The polymers PANI and POEA were synthesized and characterized ii) these films (PANI, POEA and PEDOT/PSS) were deposited by self-assembly on gold interdigited microelectrodes. The sensibility of these films to different pesticides was evaluated; iii) the interactions between pesticides and polymers were monitored by visible ultraviolet spectroscopic (UV-VIS) and microscopy techiques (SEM); iv) the sensing units were characterized by impedance measurements and by Principal Component Analysis (PCA). Using eight sensing units with PANI, POEA and PEDOT/PSS films it was demonstrated the possibility to detect some pesticides in concentration of 1 µ mL-1 and to distinguish contaminated samples from non contaminated

L‘objectif du présent travail est de démontrer la versatilité de méthodologie radiolytique et de l‘étendre à la synthèse de différents PCs dans l‘eau. Le poly(3,4-ethylènedioxythiophène), PEDOT, et le polypyrrole, PPy, ont ainsi été préparés avec succès et caractérisés en solution aqueuse, ou après dépôt sur substrat, par des techniques spectroscopiques et microscopiques. La stabilité thermique et la conductivité électrique de ces matériaux radio synthétisés ont été étudiées et comparées aux propriétés des PCs produits par les méthodologies traditionnelles. Nous avons étudié l‘influence de la nature des espèces radiolytiques oxydantes, de la force ionique du milieu, du pH de la solution et de la présence de surfactants, sur le mécanisme de croissance des PCs, sur le rendement de polymérisation, sur la morphologie des matériaux radio synthétisés ainsi que sur les propriétés optiques et électriques de ces derniers. Nous avons utilisé la radiolyse pour la synthèse de nano composites hybrides à base de PCs et de métaux de transition. Plusieurs voies de synthèse ont été développées : synthèse en une ou deux étapes, par oxydation ou réduction des monomères. La nouvelle stratégie de synthèse par radiolyse, qui est décrite dans ce manuscrit, ouvre la voie à la préparation de très nombreuses familles de PCs et de leurs composites, que ce soit en solution aqueuse ou dans des environnements alternatifs (en milieu organique, sur support, en milieu hétérogène), ce qui laisse augurer de nombreuses applications fort prometteuses / The aim of the present work is to demonstrate the versatility of the gamma (γ)-rays based radiolytic method and to extend our methodology to the synthesis of various conducting polymers (CPs) in water in different experimental conditions. Poly(3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPy) conjugated polymers were successfully prepared and characterized in solution and after deposition by complementary spectroscopic and microscopic techniques. Also their thermal stability and their electrical conductivity were studied and compared with those of CPs prepared by conventional methods. The influence of the nature of radiation-induced oxidizing radicals, of the ionic strength, of the medium, of the pH, of the presence of surfactant-based soft templates on the growth mechanism, on the efficiency of polymerization, on the morphology of the obtained CPs as well as on their absorption and conducting properties was checked. Also, the radiolytic method was extend to the synthesis of CPs/noble metal nanocomposites. Different preparation methodologies were developed based on two-step method and one-pot method, by using oxidation route or reduction route. Our new radiolytic strategy described and extended in this manuscript opens the way for the preparation of different kinds of CPs and CPs nanocomposites not only in aqueous solutions but also in various environments foreshadowing many promising applications..

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22706号 / 工博第4753号 / 新制||工||1743(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 江口 浩一, 教授 陰山 洋, 教授 阿部 竜 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Functional materials are essential to human welfare and to provide foundations for emerging industries. As an alternative route to experimental materials discovery, computational materials designs are playing an increasingly significant role in the whole discovery process. In this work, we use an in-house developed python utility: PAOFLOW, which generates finite basis Hamiltonians from the projection of first principles plane-wave pseudopotential wavefunctions on pseudo atomic orbitals(PAO) for post-process calculation on various properties such as the band structures, density of states, complex dielectric constants, diffusive and anomalous spin and charge transport coefficients. In particular, we calculated the dielectric function of Sr-, Pb-, and Bi-substituted BaSnO3 over wide concentration ranges. Together with some high-throughput experimental study, our result indicates the importance of considering the mixed-valence nature and clustering effects upon substitution of BaSnO3 with Pb and Bi. We also studied two prototype ferroelectric rashba semiconductors, GeTe and SnTe, and found the spin Hall conductivity(SHC) can be large either in ferroelectric or paraelectric structure phase. Upon doping, the polar displacements in GeTe can be sustained up to a critical hole concentration while the tiny distortions in SnTe vanish at a minimal level of doping. Moreover, we investigated the sensitivity of two dimensional group-IV monochalcogenides to external strain and doping, which reveal for the first time giant intrinsic SHC in these materials, providing a new route for the design of highly tunable spintronics devices based on two-dimensional materials.

There are sumarized some of the basic organic materials for produce of organic parts. Two types of theese materials are introduced PPV and PFV and their derivatives, which tuning their resulting properties in area of electrical, optical, chemical, and thermal parameters. There is designed and created system for mechanical bending of adhesive SMD devies on flexible printed circuit board and compared properties of some conducting adhesives.

The evaluation of concentration of ions and molecules with the help of biosensors have been regarded as an emerging technology. Bio and chemical sensors have a variety of applications in the field of medicine, military, environmental and food industries alike. With an estimated investment growth of over 4.31% in the development of pH sensors in the next five year, the objective of a developing a robust measurement system is all the more required. The scope of this research is to evaluate the ability of conducting polymer-based gel electrolytes for pH sensitivity, as a function of the transistor characteristics using an Extended Gate Field Effect Transistor or a conducting film in an electrochemical cell. Polymer gels were prepared by dissolving a suitable conducting polymer in an acidic media. The interaction of the gel with a buffer solution of known pH was collected as electric signals using a glassy carbon as an electrode. The electrochemical cell was further connected to the gate of a Metal-Oxide-Semiconductor Field Effect transistor (MOS-FET). The drain current was measured under two conditions; a) voltage across the gate (VGS) was kept constant, with varying voltage across the drain (VDS) and b) voltage across drain was fixed, while gate voltage changed. The drain current versus voltage of the transistor was plotted as a function of the ion interaction between the gel and the buffer. Different plots were recorded for different values of pH solutions. Final results were plotted to calculate the change in threshold voltage, for every change in pH of the observed solution. pH sensitivity of the gels was further tested through the Electrochemical Impedance Spectroscopy method, using a potentiostat and a three-electrode electrochemical cell. With a small excitation, the AC current flowing through the circuit at different frequencies were recorded and the plots discussed, to evaluate sensitivity to pH.

Description détaillée du sujet : Au cours des dernières années, les électrodes recouvertes d’un film polymère déposé par voie électrochimique ont suscité un engouement croissant dans le domaine des capteurs chimiques et des biocapteurs. Un exemple d’application est celui des capteurs de pH potentiométriques qui utilisent les atomes d’azote présents dans des polymères pour détecter des variations de pH. Ces électrodes sont intéressantes en vue d’applications cliniques et biologiques comme l’analyse in vivo dans la mesure où elles sont, contrairement aux électrodes de pH traditionnelles, miniaturisables tout en étant biocompatibles si les polymères choisis le sont également. Le développement d’un capteur enzymatique permettant de quantifier la présence d’urée dans un échantillon liquide est également d’un intérêt significatif dans la mesure où l’urée, qui est présente dans l’organisme humain, est un des indicateurs biologiques du bon fonctionnement des reins. En effet, des taux élevés d’urée révèlent une insuffisance rénale. De plus le contrôle des quantités d’urée est d’intérêt dans l’industrie agro-alimentaire et le contrôle environnemental. Les polymères électrodéposés peuvent également être utilisés comme supports de culture de cellules biologiques ce qui peut permettre de développer des applications dans le domaine de la médecine, par exemple pour le développement de prothèses, la lutte contre les maladies neurogénératrices, la création de muscles artificiels. Par conséquent, nous souhaitons proposer une thèse portant sur l’élaboration de films polymères originaux permettant le développement de nouveaux (bio)capteurs électrochimiques et de promouvoir des applications dans le domaine de la médecine / Detailed description of the subject: during the last years, electrodes covered with a polymer movie put down by electrochemical way aroused a craze growing in the field of the chemical sensors and the biosensors. An example of application is the one sensors of pH potentiométriques who use the present atoms of nitrogen in polymers to detect variations of pH. These electrodes are interesting with the aim of applications clinical and biological as the in vivo analysis as far as they are, contrary to the traditional electrodes of pH, miniaturisables while being biocompatible if the chosen polymers are also. The development of an enzymatic sensor allowing to quantify the presence of urea in a liquid sample is also

Our aim in the present work is to provide and evaluate AC and DC characteristics of the polyaniline based materials. Different experiemtal techniques and devices have been used to achieve this goal. An introduction to the theoretical concepts of conductivity is given as well. The core of this thesis is an investigation of temperature and low pressure dependences, as well as the ageing effects for two systems (composites) in respect of the different preparation conditions such as dopants and their molar concentration, origin and the content of inorganic component and the way of polymerisation. An agreement with theoretical models is discussed.