Made available in DSpace on 2017-07-10T15:14:40Z (GMT). No. of bitstreams: 1 Karine_N_Lupatini.pdf: 2653837 bytes, checksum: 3f96563a78bfc1de4ba5e308ad1fe38b (MD5) Previous issue date: 2016-03-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The biopolymer Chitosan has become object of several studies in recent years as proton conductive polymer membrane of hydrogen into PEM fuel cells. The main reasons are related to the possibility to undergo chemical and physical changes due to amine groups present, and its low cost. The schoolwork testing Chitosan membranes as proton conductivity, generally employ arrays of other polymers together, forming composites with properties better suited for this purpose. Very few schoolwork bother to study the effect of the properties of chitosan on the obtaining of these membranes, and Chitosan membranes are usually employed. The aim of this project was to develop membranes of Chitosan from shrimp shell of fresh water produced in Western Paraná, to be used as electrolyte fuel cells and comparing the results with those presented by the use of commercial Chitosan sample. This schoolwork investigated the influence of degree of deacetylation (GD), molar mass and reticulation of the different samples of chitosan on the performance of the membranes obtained front proton conductivity, water absorption, ion exchange capacity, mechanical strength, XRD and TGA. Chitosan QB, produced in the laboratory, presented desired characteristics of 76% GD and molar mass of 64 kDA. These properties have improved the performance of Chitosan membranes, as well as the crosslinking. The FTIR analysis proved that the crosslinking did not alter the functional groups of Chitosan, while the DRX found that the character of the MQBs became more amorphous than the MQAs and, in general, by the dTG says that the membranes have thermal stability up to 600-700° C, suitable to be applied in CaC. MQB04 and MQB05 membranes resulted in higher conductivity of 1.9 and 1.6 x 10-2 respectively and, in this case, the crosslinking provided better mechanical resistance of up to 45 N to the MQB04 membrane. The protonic conductivity obtained for MQB04 and MQB05 was significant, but still low compared to Nafion®. However, the versatility of Chitosan and the possibility of exploration and chemical modifications of its structure, still making it attractive for the research and development of Proton conducting polymeric membranes with superior performance to found in this schoolwork / O biopolímero quitosana tem se tornado objeto de vários estudos nos últimos anos como membrana polimérica condutora de prótons de hidrogênio em células a combustível do tipo PEM. As principais razões estão relacionadas à possibilidade de sofrer modificações físicas e químicas devido aos grupos amina presentes, e a seu baixo custo. Os trabalhos que testam membranas de quitosana como condutoras de prótons, geralmente empregam matrizes de outros polímeros em conjunto, formando compósitos com propriedades mais adequadas para esta finalidade. Pouquíssimos trabalhos se preocupam em estudar o efeito das propriedades da quitosana sobre a obtenção destas membranas, sendo que normalmente membranas de quitosana comercial são empregadas. O objetivo do presente trabalho foi desenvolver membranas de quitosana extraída de carapaças de camarão de água doce produzidos na região oeste do Paraná, para serem empregadas como eletrólito em células a combustível, comparando os resultados obtidos com aqueles apresentados pelo uso de amostra de quitosana comercial. Este trabalho investigou a influência do grau de desacetilação (GD), massa molar e reticulação das distintas amostras de quitosana, sobre o desempenho das membranas obtidas frente à condutividade protônica, absorção de água, capacidade de troca iônica, resistência mecânica, DRX e TGA. A quitosana QB, produzida no laboratório, apresentou características desejadas de GD de 76% e massa molar de 64 kDA. As propriedades de QB melhoraram o desempenho das membranas de quitosana, assim como a reticulação. A análise de FTIR comprovou que a reticulação não alterou os grupos funcionais da quitosana, enquanto que a DRX constatou que o caráter das MQBs tornou-se mais amorfo que às MQAs. As membranas MQB04 e MQB05 resultaram em condutividades superiores de 1,9 e 1,6x10-2 respectivamente e, neste caso, a reticulação proporcionou melhor resistência mecânica de até 45 N para a membrana MQB04. A condutividade protônica obtida para MQB04 e MQB05 foi expressiva, porém, ainda baixa se comparada ao Nafion®. Entretanto, a versatilidade da quitosana e a possibilidade de exploração e de modificações químicas da sua estrutura, continua tornando-a atrativa para a pesquisa e desenvolvimento de membranas poliméricas condutoras de prótons com desempenho ainda superior aos encontrados neste trabalho

The goal of this research project was to characterize the physical and electrochemical properties of a commercially available fuel cell-based breath alcohol sensor. Characteristics of the existing sensor were compared with state of the art power generating fuel cells with the goal of understanding the factors that limit performance, lifetime and cost effectiveness of the sensors. This will guide the development of the next generation of breath alcohol sensors. The average lifetime of the current sensor falls short of the industry standards. In particular, sensors operating in dry conditions experience more rapid loss of sensitivity and failure. Two primary causes of degradation were investigated in this study. Loss of proton conductivity as a result of membrane dehydration was shown to be reversible by rehydrating the membrane in humid conditions. Loss of electrochemically active surface area of Pt is irreversible and seems to be caused by a change in sensor morphology after long-term exposure to dry conditions. / UOIT

The proton exchange membrane fuel cells should have three major advantages: 1. micro-phase separation, 2. mechanical properties and 3. thermal stability. According to the recent literature and the material of core benzene ring poly (arylene ether)s studied by our group, this paper synthesize a series of the locally and densely sulfonated polymer. We use core benzene ring as the diol monomer and the containing CF3 groups as the fluorine monomer to synthesis poly (arylene ether)s via nucleophilic displacement reactions, and then use the different concentrations synthesized sulfonated polymer by sulfonic acid reaction. According to NMR¡¦s result we confirmed that the structure of synthetic materials is correct. By using GPC we get that the KP1, KP2, and KP3¡¦s molecular weight about 20000 (g/mol) ; The thermal stability up to 530OC for 5% loss in TGA under nithtrogen, to prove thisseries of polymer excellent thermal stability. After sulfonation, SKP1, SKP2 and SKP3¡¦s decomposition temperature decreased about 200OC ~ 250OC ranging with increasing degree of sulfonation. By DSC analysis, K1, K2 and K3 monomer's Tg followed up with the increase of the benzene ring number, however, the polymer does not have any apparent peak. About the Proton conductive, SKP2C IEC 2.23mequiv / g, water uptake 94%, the highest proton conductivity can be as high as 68.2 mS / cm, has been similar to Nafion 117 of 70 mS / cm.

Proton Exchange Membrane Fuel Cell has the potential to become an important energy conversion technigne. Lots of efforts oriented toward the electrochemical conversion of energy using proton exchange membrane (PEM) fuel cells have been enormously accelerated with the hope to promote as an alternative power source for transport and portable purposes. However, they still suffer from such disadvantages as limited operation temperature, high cost, insufficient durability and high methanol permeability.Good membranes should meet several strict requirements as follows; reasonable proton conductivity, high stability and durny the performance of a fuel cell environment,outstanding mechanical toughness, high heat endurance, and impermeability to fuel gas or liquid. Presently,a lot of references have mentioned some sulfonatied polymer sulfonated of poly(ether ether ketone) (SPEEK), sulfonatedpolysulfone (SPSF), sulfonated polysulfide sulfone(SPSS), and polybenzimidazole(PBI) and so on.To achieve high proton conductivity usually match with a high degree of sulfonation that means owning a large Ion Exchange Capacity, IEC.But which in turn leads to a decrease in the electrochemical¡Bdimensional stability¡Bwater uptake¡Boxidative stability. Therefore they suffer from such disadvantages as limited operation range of temperature.Three aromatic poly(arylene ether)s P4b¡BP4c¡BP4d were synthesized from the polymer consists nine of polyaromatic groups with bisfluoride monomer at studying long time in our laboratory with S1¡BS2¡BS3 diol monomer.The molecular weight of the polymer (Mw:1.49¡Ñ105~5.3¡Ñ105 g/mol ,PDI: 1.82~2)This polymer has high strength,thermal stability and all of polymers own very high Td ,which are over than 500oC.We sulfonatied the polymer in order to apply as the proton exchange membrane of a fuel cell.The results showed after sulfonation of P4b¡BP4c¡BP4d.All IEC reaches 3.9~1(meq/g).According to above result, we propose the aromatic poly(arylene ether)s is good matenal can be used on all application as a proton exchange membrane.

In this work, zeolite Beta was synthesized experimentally in order to be used as filler in fuel cell membranes in order to assess the proton conductivity of composite membranes. Effects of the Si/Al ratio, and synthesis time on yield, relative crystallinity, crystal size, and proton conductivity were investigated. Zeolite Beta with Si/Al ratio between 10 and 30 was synthesized with a batch formulation of 2.2Na2O:1Al2O3:ySiO2:4.6(TEA)2O:tH2O (where TEA&amp / #8801 / tetraethylammonium) at 150&deg / C for 5-15 days of synthesis time. Sodium aluminate, tetraethylammonium hydroxide (TEAOH) solution, sodium hydroxide pellets (NaOH), and deionized water were used for the preparation of the batch solution. Zeolite Na-Beta was calcined and treated with sulfuric acid solution at different concentrations in order to have zeolite H-Beta. Polyetherether ketone (PEEK) was sulfonated in order to have a proton conductive membrane and than zeolite H-Beta was incorporated resulting in a composite or nanocomposite membrane. X-ray diffraction (XRD) analysis helped to understand whether the synthesized material was zeolite Beta or not. The morphology and the crystal size of the crystals were observed as a result of the scanning electron microscopy (SEM) analysis. In order to see the effect of sulfuric acid treatment on the sodium (Na) content of the zeolite Beta, inductively coupled plasma (ICP) analysis was performed. Synthesis results indicate that as Si/Al ratio and synthesis time increased the yield of zeolite Beta increased. It was observed that Si/Al ratio from 10 to 30, and synthesis time between 5 to 15 days did not affect the crystal size significantly. For the sulfonation of PEEK, sulfuric acid was used. Sulfonated polyetherether ketone (SPEEK) was dissolved in a solvent that was dimethyl acetamide (DMAC), incorporated with zeolite Beta, and then solvent was removed in the vacuum oven. The proton conductivity was measured with a 2-probe impedance spectrometer. Initial results indicate that zeolite Beta at 10 and 20 wt % loadings did not affect the proton conductivity of the SPEEK membrane at 100 % relative humidity and room temperature.

ABSTRACT BIOSENSOR BASED ON INTERPENETRATED POLYMER NETWORK OF ALGINIC ACID AND POLY (1-VINYLIMIDAZOLE) Kartal, M&uuml / jgan M.S., Department of Chemistry Supervisor : Prof. Dr. Levent Toppare January 2008, 63 pages A new proton conductor polymer was prepared using alginic acid (AA) and poly (1-vinylimidazole) (PVI). The polymer network was obtained by mixing AA and PVI at various stoichiometric ratios, x (molar ratio of the monomer repeat units). The AA/PVI network was characterized by elemental analysis (EA) and FT-IR spectroscopy. Potential use of this network in enzyme immobilization was studied. Enzyme entrapped polymer networks (EEPN) were produced by immobilizing invertase and tyrosinase (PPO) in the AA/PVI network. Additionally, the maximum reaction rate (Vmax) and Michaelis-Menten constant (Km) were investigated for the immobilized invertase and enzymes. Also, temperature and pH optimization, operational stability and shelf life of the polymer network were examined.

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-08-07T14:27:04Z No. of bitstreams: 0 / Made available in DSpace on 2015-08-07T14:27:04Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:11/50197-0

abstract: This thesis studies three different types of anhydrous proton conducting electrolytes for use in fuel cells. The proton energy level scheme is used to make the first electrolyte which is a rubbery polymer in which the conductivity reaches values typical of activated Nafion, even though it is completely anhydrous. The protons are introduced into a cross-linked polyphospazene rubber by the superacid HOTf, which is absorbed by partial protonation of the backbone nitrogens. The decoupling of conductivity from segmental relaxation times assessed by comparison with conductivity relaxation times amounts to some 10 orders of magnitude, but it cannot be concluded whether it is purely protonic or due equally to a mobile OTf- or H(OTf)2-; component. The second electrolyte is built on the success of phosphoric acid as a fuel cell electrolyte, by designing a variant of the molecular acid that has increased temperature range without sacrifice of high temperature conductivity or open circuit voltage. The success is achieved by introduction of a hybrid component, based on silicon coordination of phosphate groups, which prevents decomposition or water loss to 250ºC, while enhancing free proton motion. Conductivity studies are reported to 285ºC and full H2/O2 cell polarization curves to 226ºC. The current efficiency reported here (current density per unit of fuel supplied per sec) is the highest on record. A power density of 184 (mW.cm-2) is achieved at 226ºC with hydrogen flow rate of 4.1 ml/minute. The third electrolyte is a novel type of ionic liquids which is made by addition of a super strong Brønsted acid to a super weak Brønsted base. Here it is shown that by allowing the proton of transient HAlCl4, to relocate on a very weak base that is also stable to superacids, we can create an anhydrous ionic liquid, itself a superacid, in which the proton is so loosely bound that at least 50% of the electrical conductivity is due to the motion of free protons. The protic ionic liquids (PILs) described, pentafluoropyridinium tetrachloroaluminate and 5-chloro-2,4,6-trifluoropyrimidinium tetrachloroaluminate, might be the forerunner of a class of materials in which the proton plasma state can be approached. / Dissertation/Thesis / Ph.D. Chemistry 2013

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-08-07T14:27:04Z No. of bitstreams: 0 / Made available in DSpace on 2015-08-07T14:27:04Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O condutor protônico zirconato de bário dopado com ítrio (BaZr1-xYxO3-δ, BZYx) é um material promissor para a aplicação como eletrólito sólido em células a combustível operacional em temperaturas intermediárias (400 a 700 oC). No entanto, sua natureza refratária (ponto de fusão ~ 2600 oC) faz com que para sua densificação, necessária para sua aplicação como eletrólito, sejam necessários altas temperaturas e longos tempos de tratamento térmico (1600 a 1800 °C por 24 a 48 h). Tais condições extremas causam um desvio da estequiometria de bário que afeta a química de defeitos do material e, consequentemente a diminuição da condutividade protônica do BZYx. Portanto, o processamento desse eletrólito sólido em menores temperaturas, preservando sua estequiometria, formando uma microestrutura densa e com baixa resistividade inter-granular são os principais objetivos e desafios da comunidade científica. Visando aumentar a sinterabilidade das partículas, o BZY foi preparado pelo método dos peróxidos oxidantes (OPM). O procedimento experimental original do OPM foi modificado e otimizado para viabilizar a formação do BZYx, com x = 10 a 50 mol% de Y3+. Dentre as modificações, a síntese foi feita com e sem o controle da atmosfera, em câmara de luvas sob atmosfera de nitrogênio e ao ar, respectivamente. As propriedades estruturais, morfológicas, térmicas, termodinâmicas e elétricas das composições de BZYx foram investigadas. As amostras produzidas foram calcinadas em diversas temperaturas e investigadas quanto à sua sinterabilidade e densificação. Os pós de BZYx, com x = 10 a 50 mol% de Y3+, produzidos com controle da atmosfera foram investigados quanto às suas propriedades termodinâmicas. Os valores de entalpia de formação a partir dos óxidos (ΔHf,ox) foram calculados com os dados obtidos por calorimetria de dissolução a alta temperatura. As amostras de BZY10 e BZY20 produzidas com controle da atmosfera atingiram condutividade elétrica total de 1,6 x 10-3 e 1,3 x 10-3 S/cm a 530 oC, respectivamente. A alta resistividade inter-granular contribui para a alta resistividade total das amostras. A análise por espectroscopia Raman e os valores de ΔHf,ox obtidos sugerem que para valores de Y3+ > 20 mol% ocorrem interações defeito-defeito na estrutura cristalina, causando à diminuição de sítios efetivos para a hidratação e a diminuição da mobilidade dos prótons na estrutura e, consequentemente, a diminuição da condutividade protônica total. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:11/50197-0

>Magister Scientiae - MSc / The production procedure of a CsHS04-Si02 composite membrane was optimized in order to obtain the highest possible H2:C02 and H2:C~ Idea selectivity permeance. The optimized membrane preparation procedure led to the preparation of membranes with Idea selectivity of 5 and 10 towards H2:C~ and H2:C02 respectively. The H2 permeance value is on average 0.15 umol- s-l·m-2.Pa-I. The reproducibility of the optimized membrane was further investigated and was found to be satisfactory. An attempt was made to discover the gas transport mechanism of H2, C~ and C02. Gas permeance measurements were carried out as a function of time and temperature (between 25-180°C) using H2, C~ and C02 as analyte gases. XRD, TGA and impedance spectroscopy were used to identify the phases of CsHS04 within the membrane. The gas permeation mechanism was found to be a combination of Knudsen diffusion and solution diffusion. The pores that allow Knudsen diffusion (allow transport of Hi, CH4 and C02) are believed to be located at the CSHS04 crystal phase boundaries. In parallel, H2 diffuses selectively through the lattice of phase II/III of CsHS04 ..