The contamination of 316L stainless steel surfaces within an electrospray ionisation source of a mass spectrometer is investigated. An accelerated method of contamination is used. Following initial test method development and investigation of the contamination resulting on the ion transfer components (sample cone, outer cone and extraction cone), flat samples are employed within the ionisation source. This enables characterisation of the contamination composition, morphology and build-up with time. Blood plasma is introduced into the mass spectrometer as it is a widely analysed substance that is known to result in contamination. The contamination from a mixture of human blood plasma, diluted in methanol, and a water/acetonitrile mobile phase is found to contain inorganic NaCl crystals embedded in a matrix of organic residues. The morphology shows self-organising features as the contamination builds. A model is proposed to explain the morphology, involving rapid evaporation of the droplets that impinge on the stainless steel surface. Two types of surface modification are considered for the stainless steel: electrochemically grown films and coatings deposited by vapour deposition. A method for electrochemical film growth is developed, enabling nanoporous films to be formed on the stainless steel in 5 M sulphuric acid at 60°C by square wave pulse polarisation between active or transpassive and passive potentials. The films are characterised using glow discharge optical emission spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, Rutherford backscattering spectroscopy and nuclear reaction analysis. The films are shown to be chromium- and molybdenum-rich relative to the substrate, and to consist mainly of sulphates, oxides and hydroxides. The morphology and composition of the films are discussed in relation to the polarisation conditions and mechanism of film formation. A range of vapour deposited coatings are considered: TiN, TiC, TiB2, Graphit-iC, and diamond-like carbon coatings with Si and N2 dopants and with varying sp2:sp3 ratios. In addition, a hydrophobic coating is deposited on the stainless steel by immersion, in order to provide a significant variation in surface energy. Surface analysis of the coatings is carried out, considering their sp2:sp3 ratios, their electrical conductivities, their water contact angle, and the various components of the surface energy. The contamination build-up on the surface of uncoated 316L stainless steel is compared with that on stainless steel with the various surface modifications. A method for quantification of the build-up of contamination on flat samples is developed using white light interferometry. The surface modifications which result in the slowest contamination build-up with time are then applied to the ion transfer components of the mass spectrometer. The robustness of the mass spectrometric response for the selected coated surfaces is compared with that of the uncoated stainless steel. The electrochemically grown films and two of the doped diamond-like carbon coatings are found to be successful in reducing the build-up of contamination.

Le but de ce projet est de concevoir un nouveau type d'étiquette ‘écologique', n'utilisant pas de dorsale siliconé. Ainsi, la couche d'adhésif est remplacée par une couche de microcapsules d'adhésif. Ces microcapsules doivent avoir une paroi suffisamment étanche et résistante pour envelopper l'adhésif et ne pas se rompre lors des étapes de fabrication du produit. Par contre, elles doivent céder sous l'effet d'une pression et libérer l'adhésif au moment de leur utilisation. Dans un premier temps, 3 adhésifs en émulsion aqueuse ont été caractérisés en vue de leur microencapsulation. Par la suite, un adhésif a été sélectionné et encapsulé par coacervation (avec des biomatériaux comme carapace) et par polymérisation in situ aminoplaste. Ensuite, 2 autres procédés d'encapsulation d'adhésif réalisés au LAGEP (le spray-drying et le spray-cooling) ont été comparés avec les 2 techniques précédentes. Les capsules produites par spray-cooling, les plus adhésives, ont permis la formulation d'un bain d'enduction en vue d'un couchage des capsules à l'aide d'une barre de Meyer, et par procédé sérigraphique. La compatibilité de ces microcapsules avec le procédé de fabrication d'une étiquette autoadhésive classique, sur une rotative d'impression flexographique, a été montrée. Les caractéristiques finales du produit ainsi fabriqué (adhésion, pression d'application) ont été comparées avec celles de différents produits autoadhésifs industriels (étiquette, enveloppe et timbre). / The main objective of this investigation is to prepare innovative silicone liner-free labels. It can be achieved by the adhesive ‘self protection', thanks to its incorporation into microcapsules. This allows the preparation of ‘dry labels' gluing under the application of a pressure, which induces the rupture of the microcapsules, thus releasing the core material, a pressure sensitive adhesive. The first step was to analyse 3 water-based PSA in view of their encapsulation. Then, the most suitable adhesive was microencapsulated by coacervation (using biopolymer as shell) and by in situ polymerisation. Two other encapsulation processes (spray-cooling and spray-drying), were also carried out at the LAGEP and were compared with the 2 former processes. Coating colour formulations were prepared with spray-cooling microcapsules (the most adhesive ones). Coating trials were carried out with a Meyer rod, and by screen printing. Compatibility between microcapsules and the label making process, using a flexographic printing press, was determined. Finally, the mains characteristics of the prepared innovative products (adhesion, application pressure) were compared to industrial self-adhesive homologues, and found that they could be suitable for the preparation of silicon liner-free envelops and stamps.

LIMA, D. R. Avaliação do desempenho anticorrosivo do revestimento de polibenzoxazina sintetizada a partir do líquido da castanha de caju. 2017. 44 f. Dissertação (Mestrado em Ciência de Materiais)-Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Hohana Sanders (hohanasanders@hotmail.com) on 2017-09-19T17:42:48Z No. of bitstreams: 1 2017_dis_drlima.pdf: 1177358 bytes, checksum: a6d5228462e2c5a3c6b66ec110abc6e6 (MD5) / Approved for entry into archive by Marlene Sousa (mmarlene@ufc.br) on 2017-09-25T17:47:55Z (GMT) No. of bitstreams: 1 2017_dis_drlima.pdf: 1177358 bytes, checksum: a6d5228462e2c5a3c6b66ec110abc6e6 (MD5) / Made available in DSpace on 2017-09-25T17:47:55Z (GMT). No. of bitstreams: 1 2017_dis_drlima.pdf: 1177358 bytes, checksum: a6d5228462e2c5a3c6b66ec110abc6e6 (MD5) Previous issue date: 2017-07-21 / The aim of this work was to evaluate the benzoxazine polymer, synthesized from the Cashew Nut Liquid (LCC) cardanol, as a coating for corrosion protection of AISI 1010 carbon steel. The physical properties of the synthesized polymer were characterized using Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA) and degree of crosslinking based on ASTM D2765. Polymeric film was prepared by brushing the benzoxazine resin on the steel surface, followed by curing at 200 °C, and its adhesion to the steel surface was evaluated by the grid cutting method according to ABNT NBR 11003. Corrosion tests consisted of exposure to saturated moisture and saline fog, and immersion in 0.6 mol L-1 NaCl solution, with the monitoring of the degradation of the coating accompanied by monitoring the open circuit potential and electrochemical impedance spectroscopy. From the thermal characterization and analysis of the swelling of the cured polymer film, it was observed that the film cured at 200 °C for 2 h had properties applicable to the use as coating since it presented 98% crosslinking with excellent thermal stability and approximately 55 μm of thickness. In the electrochemical tests the presence of the plasticizer in the benzoxazine polymer matrix influenced the coating efficiency. When compared to the concentrations of 5% and 10% of the plasticizer in the electrochemical tests, the concentration of 10% of the plasticizer was more protective against corrosion compared to 5%. These results suggest that benzoxazines synthesized from cardanol from Cashew Nut Liquid (LCC) can be used as an alternative coating for corrosion protection on AISI 1010 carbon steel surfaces. / Este trabalho teve por objetivo avaliar o polímero benzoxazina, sintetizado a partir do cardanol proveniente do Líquido da Castanha de Caju (LCC), como revestimento para a proteção à corrosão do aço carbono AISI 1010. As propriedades físicas do polímero sintetizado foram caracterizadas usando as técnicas de Calorimetria Exploratória Diferencial (DSC), Análise Termogravimétrica (TGA) e grau de reticulação baseado na norma ASTM D2765. O filme polimérico foi preparado pelo pincelamento da resina de benzoxazina na superfície do aço, seguido de cura a 200 °C, sendo que sua aderência à superfície do aço foi avaliada pelo método do corte em grade segundo a norma ABNT NBR 11003. Os testes de corrosão consistiram de exposição à umidade saturada, à névoa salina e imersão em solução de NaCl 0,6 mol L-1, sendo que o monitoramento da degradação do revestimento foi acompanhado por monitoramento do potencial de circuito aberto e espectroscopia de impedância eletroquímica. A partir da caracterização térmica e da análise do intumescimento do filme polimérico curado, verificou-se que o filme curado a 200°C por 2 h apresentou propriedades aplicáveis ao uso como revestimento, pois apresentou 98 % de reticulação com excelente estabilidade térmica e espessura em torno de 55 µm. Nos ensaios eletroquímicos a presença do plastificante na matriz polimérica das benzoxazinas influenciou a eficiência do revestimento. Quando comparadas as concentrações de 5 % e 10 % do plastificante nos ensaios eletroquímicos, a concentração de 10 % do plastificante mostrou-se mais protetora contra corrosão em comparação à 5 %. Estes resultados sugerem que benzoxazinas sintetizadas a partir do cardanol proveniente do Líquido da Castanha de Caju (LCC) podem ser utilizadas como um revestimento alternativo para proteção contra corrosão em superfícies de aço carbono AISI 1010.

Light reflection from the glass surface of a photovoltaic (PV) module is a significant source of energy loss for all types of PV devices. The reflection at the glass and air interface accounts for ~4% of the total energy. Single layer anti-reflection coatings with sufficiently low refractive index have been used, such as those using magnesium fluoride or porous silica, but these are only effective over a narrow range of wavelengths. Multilayer-antireflection coatings reduce the weighted average reflection over the wavelength range used by solar technologies more effectively by utilising interference effects. Multilayer stacks consisting of silica and zirconia layers deposited using reactive magnetron sputtering and single layer porous silica coatings were compared in terms of effectiveness and durability. Details of the stack design, sputter deposition process parameters, and the optical and micro-structural properties of the layers of the multilayer coating are provided and similar properties where applicable for the single layer coatings. Anti-reflection coatings on glass exposed to the outdoors must not degrade over the lifetime of the module. A comprehensive set of accelerated environmental durability tests has been carried out in accordance with IEC 61646 PV qualification tests. The durability tests confirmed no damage to the coatings or performance drop as a result of thermal cycling or damp heat. All attempts to perform pull tests on either coating resulted in either adhesive or substrate failure, with no damage to the coating itself. Scratch resistance, abrasion resistance, and adhesion tests have also been conducted. The optical performance of the coatings was monitored during these tests and the coatings were visually inspected for any sign of mechanical failure. These tests provide confidence that broadband anti-reflection coatings are highly durable and will maintain their performance over the lifetime of the solar module. Additionally heat treatment experiments demonstrated both coatings can withstand up to 600°C temperatures and can thereby withstand CdTe manufacturing processes allowing for pre-coated glass. Additionally experiments demonstrated that multi-layer coatings are resistant to acid attack. Thin film photovoltaic devices are multilayer opto-electrical structures in which light interference occurs. Light reflection at the interfaces and absorption within the window layers reduces transmission and, ultimately, the conversion efficiency of photovoltaic devices. Optical reflection losses can be reduced by adjusting the layer thicknesses to achieve destructive interference within the structure of the cell. The light transmission to the CdTe absorber of a CdS/CdTe cell on a fluorine doped tin oxide transparent conductor has been modelled using the transfer matrix method. The interference effect in the CdS layer and high resistance transparent buffer layers (SnO2 and ZnO) has been investigated. The modelling shows that due to relatively high absorption within the SnO2 layer, there are modest benefits to engineering anti-reflection interference in the stack. However, a ZnO buffer layer has limited absorption and interference can be exploited to provide useful anti-reflection effects. Additionally the light transmission to the perovskite absorber of a thin film solar cell using fluorine doped tin oxide (FTO) transparent conductor has been modelled. Alternative transparent conductor materials have also been investigated including aluminium doped zinc oxide (AZO) and indium tin oxide (ITO) and shown to be beneficial to transmission.

In recent decade growing concerns of CO2 emissions from power plants have increased, which led to development of technologies like oxy-fuel combustion process. P91 steel is profoundly used in power plants, but oxy fuel combustion exacerbates corrosion due to recycling of flue gas. This paper studied the kinetics of the corrosion rate on the boiler tubes and furnace and help achieve a corrosion resistant coating over it. Refractory metal diffusion coating is created and tested at high temperature in corrosive atmosphere. This was done by forming Ti and Zr diffusion coating on P91 steel using pack cementation. Coating thickness of 12 and 20 µm were obtained for Ti and Zr respectively. These samples were tested in thermo-gravimetric system by heating at 950˚C for 24 hours in 5% oxygen in Helium gas. Heating in an oxidizing environment lead to exfoliation corrosion on uncoated P91 steel. TGA procedure confirmed less mass change of Ti and Zr coated samples, than that of uncoated P91 steel sample. SEM and depth profiling confirms oxygen penetration is 2.7mm in uncoated P91 steel sample, whereas the Ti and Zr Coated samples oxygen penetration is just 16 and 56 µm respectively.

O sistema de revestimento de argamassa é formado por diversas etapas, preparo da base, emboço, reboco e acabamento decorativo. Apesar de ser uma técnica bastante difundida, em muitos casos, a produção racionalizada e eficiente ainda não está consolidada, ocorrendo em falhas, elevados desperdícios e problemas quanto ao seu desempenho. A eliminação de etapas se apresenta como uma alteração viável aumentar a produtividade, reduzir as perdas, diminuir o consumo de materiais e simplificar o sistema. Neste contexto, surge o sistema de revestimento de argamassa decorativa monocamada. Este sistema de revestimento utiliza uma argamassa pigmentada, eliminando a necessidade de pintura e pode ser aplicada sobre substratos de alvenaria ou concreto estrutural. Por se tratar de um revestimento decorativo, deve ser capaz de atender as expectativas estéticas, apresentando conformidade de cor por toda extensão revestida. No entanto, devido a eliminar etapas, diminuir espessura e por ser uma argamassa com maior complexidade em relação à utilizada na técnica tradicional, pode ocorrer variações de cor no revestimento..Neste sentido, este trabalho buscou identificar os fatores que influenciam na variação de cor do revestimento decorativo monocamada. Para tanto, foram avaliados 4 substratos (vidro e 3 cerâmicos, queimadas a 800, 900 e 1000°C) e utilizou-se diferentes espessuras do revestimento (1, 2 e 3 cm). Também avaliou-se o efeito da quantidade de água na mistura e a temperatura de cura inicial. Utilizou-se um espectrofotômetro para a verificação da cor, e como resposta, adotou-se os sistemas L*a*b* e L*C*h(°). Analisou-se o efeito das variáveis estudadas sobre a cor e posteriormente determinou-se a diferença de cor através do cálculo do ΔE, sendo as diferenças obtidas classificadas quanto sua percepção. Observou-se que em sua maioria, os efeitos impostos geraram algum tipo de variação nos fatores que compõem a cor. Porém, nem sempre geram variações de cor perceptíveis. As maiores diferenças de cor foram obtidas nas primeiras idades. / Mortar coatings are made through of several steps, such as substrate preparation, mortar plaster and decorative finish. Despite being an rather widespread technique, In many cases, optimized and efficient production is still not consolidated, leading to failure, substantial losses and problems with performance. The elimination of some steps is presented as a feasible opportunity to increase productivity, waste reduction, reduce of consumption of raw materials and system simplification. In this context, the monolayer mortar coating system is an interesting option. This system uses a pigmented coating mortar, eliminating the painting and can be applied to masonry substrates or structural concrete. As this is a decorative coating, The system must be able to attend the aesthetic expectations, showing conformity of color throughout coated extension. However, due to eliminate steps and reduce the thickness to be a mortar with more complex compared to the traditional technique used, the color variations can occur in the coating. Thus, this study aim to identify factors that influence the color variation of the decorative monolayer coating. Thus, four substrates were evaluated (3 glass and ceramic, fired at 800, 900 and 1000°C) and used different coating thicknesses (1, 2 and 3 cm). This paper also evaluated the effect of the amount of water in the mixture and the initial cure temperature. It was used a spectrophotometer to check the color response, and adopted the L*a*b* and L*C*h(°). The analysis have been made calculating the effect of the variables on color and then the color difference ΔE. The differences obtained are classified from its perception. It was observed that in most cases, the effects taxes have generated some variation in the factors that make up the color. However, not always produced notable changes in color. The greatest differences in color were obtained at early ages.

Supercapacitors have attracted great attention because of their high power density, long life cycle and high efficiency. They can be generally classified into two types: electrical double-layer capacitors (EDLCs) and pseudocapacitors. Compared with pseudocapacitors, EDLCs have a very fast charge/discharge rate, higher power density, higher coulombic efficiency and longer cycle life. Recently, in order to meet the requirements of portable and wearable electronics, supercapacitor development is moving towards flexible and stretchable solutions. This thesis presents the design, fabrication, performance testing and optimisation of flexible strip and fibre EDLCs. In this research, a sandwich structured strip EDLC was designed and manufactured. Experimental design was utilised to optimise the operation parameters of the EDLC in order to improve its capacity for energy storage. The flexibility of the strip EDLCs was studied extensively by mechanical tests under static and dynamic loading conditions, and the correlation between the electrochemical performance of the EDLCs and the mechanical testing process was investigated. Novel coaxial fibre EDLCs have also been studied and developed in this study. Fibre supercapacitors showed a good flexibility and weavability. The activated carbon produced by ball-milling method with optimum specific capacitance was mixed with commercial ink to produce active material to optimise the electrochemical performance of fibre EDLCs. The flexible EDLCs were applied into different appliances to demonstrate the stability of performance and the usability of EDLCs developed in this study. The electrical current and potential range can be altered by connecting multiple strip or fibre EDLCs in parallel or in series to meet the power and energy requirements. It has been proved that the flexible EDLCs developed have a great potential to be used as energy storage devices for smart electronics. This thesis makes original contributions to knowledge, including using an advanced test method to study the electrochemical performance of flexible supercapacitors under static and dynamic mechanical testing, investigation of the effect of key parameters in the manufacturing process on the performance of strip supercapacitors using experimental design method to optimise the supercapacitors’ performance, and optimisation of the performance of fibre supercapacitors by improving the structure and using a new active material with higher specific capacitance.

Esta tese tem por objetivo o desenvolvimento de metodologias eficientes e de baixo custo para ajustar as propriedades elétricas de OFETs de canal p e de canal n, a fim de possibilitar a fabricação do circuito complementar orgânico, semelhante a uma estrutura CMOS. O desempenho do circuito complementar fabricado foi otimizado, e também foi confeccionado por impressão um OFETs de canal operando em baixas tensões. Para a fabricação do CMOS orgânico foi proposto um método baseado na seleção adequada do solvente da camada dielétrica para ajustar o desempenho elétrico dos OFETs de canal p e de canal n. Os solventes, MEK, nBA e DMSO foram selecionados para a dissolução do PMMA por apresentarem diferenças nos valores de momento de dipolo, de ponto de ebulição e de graus de ortogonalidade em relação as camadas semicondutoras de P3HT e de P(NDI2OD-T2) dos OFETs. A análise dos resultados dos OFETs de canal p e de canal n demonstrou que a metodologia proposta é adequada tanto para o ajuste das propriedades elétricas destes dispositivos quanto para a otimização do desempenho dos mesmos. Os melhores desempenhos elétricos para os OFETs de canal p e de canal n foram obtidos quando utilizados o DMSO e o MEK como solventes do PMMA, respectivamente, devido à perfeita ortogonalidade destes solventes em relação às camadas semicondutoras. Os OFETs de canal p que utilizaram o DMSO e os OFETs de canal n que utilizaram o nBA foram os que apresentaram desempenhos elétricos semelhantes, sendo portanto aplicados na fabricação do CMOS. Valores de ganho entre 6,8 e 7,8 e de margem de ruído entre 28,3 V e 34,5 V foram obtidos para inversores complementares fabricados nesta etapa do trabalho. OFETs de canal p utilizando uma blenda de PTAA: diF TES ADT como camada semicondutora, o PEDOT:PSS como eletrodos dreno/fonte e o P(VDF-TrFE-CFE) como camada dielétrica também foram fabricados neste trabalho. A técnica de blade-coating foi utilizada para a deposição dos eletrodos dreno/fonte e da camada semicondutora, ao passo que a técnica de spray-coating foi utilizada para a deposição da camada dielétrica. Da análise dos resultados foi possível inferir que a utilização de um dielétrico com elevada constante dielétrica (K), como o P(VDF-TrFE-CFE), possibilita o funcionamento dos transistores a baixas tensões (≤ 8 V), porém com valores de mobilidade reduzidos devido à elevada desordem dipolar na interface provocada por este dielétrico. Para minimizar esses efeitos, uma fina camada de um polímero fluorado foi depositada entre a camada semicondutora e a dielétrica pela técnica de blade-coating, constituindo assim uma bicamada dielétrica nos OFETs. Dos resultados das medidas elétricas dos OFETs constituídos pela bicamada dielétrica foi observada permanência do funcionamento destes dispositivos a tensões inferiores a 8 V com desempenho elétricos superiores a resultados já publicados na literatura. Por fim, inversores lógicos unipolares com transistores de carga foram fabricados com os OFETs que utilizaram a bicamada dielétrica, sendo obtidos valores de ganho entre 1,2 e 1,6 e de margem de ruído entre 56% e 68,5% de ½ VDD. / This thesis aimed to develop an efficient and low cost method to adjust the electrical properties of p- and n-channel OFETs to allow us to build an organic CMOS and the optimization of printed p-channel OFETs to work at low voltages. We proposed a method to fabricate the organic CMOS, based on the careful selection of dielectric solvent, which was adjusted to obtain the best performance of p- and n-channel OFETs. The dielectric solvents as MEK, nBA and DMSO were selected to dissolve the PMMA dielectric polymer due their different physical properties as dipole moment and boiling point and because they showed slightly different degrees of orthogonality to the P3HT and P(NDI2OD-T2) semiconductor layers of the OFETs. The results showed that the careful selection of the dielectric solvent not only allows to tune the electrical characteristics of the p- and n-channel OFETs, but also to improve the performance of these devices. The best performances were achieved when DMSO and MEK were used as dielectric solvents of the p and n-channel OFETs, respectively, as result of the perfectly orthogonality of these solvents to the semiconductor layers. P-channel OFETs using DMSO and n-channel OFETs using nBA showed similar electrical characteristics and thus, they were used to construct the organic CMOS. The organic complementary inverters showed high gain and noise margin values in the range of 6,8 to 7,8 and 28,3 V to 34,5 V, respectively. Printed p-channel OFETs were also fabricated, in which the blend PTAA:diF TES ADT was used as semiconductor channel, PEDOT:PSS as the drain/source electrodes and P(VDF-TrFE-CFE) as the dielectric layer. The blade-coating technique was used to deposit the source/drain electrodes and the semiconductor layer, while the spray-coating technique was used to deposit the dielectric layer. It was observed that using high-k dielectric as P(VDF-TrFE-CFE) enable to reduce the operating voltage of the OFETs (≤8 V), however, this high-k dielectric also reduced the field effect mobility due the dipolar disorder at the semiconductor/dielectric interface. To minimize the dipolar issue at the interface, we inserted a thin fluoropolymer dielectric layer by blade-coating between the semiconductor and the high-k dielectric layers, thus constituting a dielectric bilayer on the OFETs. From the electrical measurements of the OFETs with the dielectric bilayer, it was observed that the devices were still working at 8 V and they also showed better performance in comparison to results already published. Finally, organic unipolar inverters with load transistors were fabricated using the p-channel OFETs with the dielectric bilayer and they showed reasonable performance, with gain and noise margin in the range of 1,2 to 1,6 and 56% e 68,5% of ½ VDD, respectively.

Orientador: Magali C. Monteiro da Silva / Banca: Natália Soares Janzantti / Banca: Renata de Marchi / Resumo: Os filmes e revestimentos biodegradáveis são usados para revestir os alimentos, agindo como barreira à umidade e a gases, reduzindo a respiração e as perdas de água por transpiração e desidratação, além do escurecimento enzimático, e mantendo as características do alimento, com aumento da vida de prateleira. Este trabalho teve como objetivos reunir informações sobre o uso da quitosana como revestimento de frutas e vegetais, visando dar suporte ao trabalho experimental; avaliar maçãs revestidas com quitosana comercial, durante o armazenamento à temperatura ambiente, simulando as condições de comercialização das frutas para o mercado interno; avaliar maçãs revestidas com quitosana comercial durante 6 meses de armazenamento sob atmosfera controlada e baixa temperatura, condições de estocagem das frutas para o mercado externo, seguido de armazenamento por 30 dias em atmosfera ambiente e baixa temperatura, visando simular o transporte das frutas para o mercado consumidor no exterior, e posteriormente estocadas à temperatura ambiente, simulando as condições de comercialização; e avaliar maçãs revestidas com quitosana modificada, quando submetidas à temperatura ambiente, visando prolongar a vida de prateleira durante a comercialização, após 6 meses de armazenamento sob atmosfera controlada e baixa temperatura, seguidos de armazenamento por 30 dias em atmosfera ambiente e baixa temperatura. Maçãs 'Royal Gala' foram produzidas na safra de 2009, e após a colheita foram separadas em 3 lotes, sendo as frutas do 1o lote revestidas com quitosana comercial; as do 2o lote imersas em solução de ácido acético, que foram usadas como branco e as maçãs do 3o lote não receberam tratamento e foram usadas como controle. Após 6 meses de armazenamento sob atmosfera controlada e baixa temperatura, seguido de mais 30 dias de armazenamento em atmosfera ambiente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The films and biodegradable coatings are used to coat the food, acting as a barrier to moisture and gases, reducing the respiration and water loss by transpiration and dehydration in addition to the enzymatic browning, maintaining the characteristics of food, with increased of shelf life. This study aimed to gather information about the use of chitosan as a coating for fruits and vegetables, aiming to support the experimental work; evaluate apples coated with commercial chitosan coating during storage at ambient temperature, simulating the real conditions of sale of the fruit for the domestic market; evaluate apples coated with commercial chitosan during 6 months of storage under controlled atmosphere and low temperature, storage conditions of fruit for the export market, followed by 30 days storage under at ambient and low temperature, in order to simulate the transport of fruit to the consumer market abroad, and subsequently stored at ambient temperature, simulating the conditions of marketing; and evaluate apples coated with modified chitosan, at ambient temperature, in order to prolong the shelf life during marketing after six months storaged under controlled atmosphere and low temperature, followed by another 30 days storage under at ambient atmosphere and low temperature. 'Royal Gala' apples were produced in 2009 crop and after the harvest they were separated into 3 lots, the first batch of fruit coated with commercial chitosan, those from second lot were immersed in an acetic acid solution and used as blank and the third lot of apples used as controls received no treatment. After 6 storage months under controlled atmosphere and low temperature, followed by another 30 days storage under at ambient atmosphere and low temperature apples without any treatment were separated in 2 lots, being the first batch of fruit coated with modified chitosan, and the second batch used as controls... (Complete abstract click electronic access below) / Mestre

Made available in DSpace on 2014-10-09T12:33:47Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:00Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP