Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-23T19:49:19Z No. of bitstreams: 1 EdianaPaulaRebitski_DISSERT.pdf: 5282849 bytes, checksum: f1a7a2f4009a400f77db6f24d30a9596 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-27T19:26:26Z (GMT) No. of bitstreams: 1 EdianaPaulaRebitski_DISSERT.pdf: 5282849 bytes, checksum: f1a7a2f4009a400f77db6f24d30a9596 (MD5) / Made available in DSpace on 2016-06-27T19:26:26Z (GMT). No. of bitstreams: 1 EdianaPaulaRebitski_DISSERT.pdf: 5282849 bytes, checksum: f1a7a2f4009a400f77db6f24d30a9596 (MD5) Previous issue date: 2015-05-22 / Bionanocomp?sitos s?o materiais nanoestruturados h?bridos org?nico-inorg?nico que envolvem uma contrapartida org?nica de origem biol?gica, por exemplo, um biopol?mero, associado a um s?lido inorg?nico em nanoescala. Materiais bioh?bridos a base de argilominerais (montmorillonita, sepiolita) e s?lidos inorg?nicos (hidr?xidos duplos lamelares) s?o uma boa op??o para diversas aplica??es (tais como biom?dicas) devido ao seu baixo custo, biodegradabilidade e biocompatibilidade. Devido a capacidade de troca i?nica, ?rea espec?fica elevada e a capacidade de adsor??o que esses materiais possuem, ? poss?vel combinar uma grande variedade de esp?cies org?nicas, tais como drogas, na qualidade de transportadoras. Neste contexto, este trabalho apresenta a prepara??o de novos bionanocomp?sitos com base na combina??o dos biopol?meros carboximetilcelulose e ze?na como revestimento do h?brido, argilomineral - antibi?tico e hidr?xidos duplos lamelares-antibi?tico. Para a s?ntese dos materiais bioh?bridos foi utilizado o antibi?tico neomicina de uso t?pico e amoxicilina de uso oral como f?rmacos modelos, o qual, foram incorporados nos argilominerais e hidr?xidos duplos lamelares por processo de intercala??o por troca i?nica e por adsor??o. / Bionanocomposites systems clay base (montmorillonite and sepiolite), layered double hidroxides and biopolymers (carboxymethylcellulose and zein) were evaluated as topical delivery systems with antibacterial activity and as oral delivery systems. For this study, neomycin, a topical antibiotic, indicated mainly for open wound infections. The drug amoxicillin, an antibiotic indicated mainly for throat infections, were also used in this study. Both antibiotics were used as model drugs. Initially, drugs were incorporated directly into the biopolymer matrix, comprising the combination of carboxymethylcellulos and zein, being conformed as movies and balls and evaluated for their antibacterial activity and controlled release simulating gastrointestinal fluids. Moreover, hybrids materials have been prepared where the neomycin drug was incorporated into the lamellar inorganic solids, such as montmorillonite by ion exchange reaction, and the fibrous type, such as sepiolite by adsorption in aqueous solution. But the drug amoxicillin was incorporated into layered double hydroxides by anion exchange and montmorillonite by cation exchange. The resulting hybrids were in turn combined with the biopolymer matrix yielding bionanocomposites shaped materials such as films were tested for their antibacterial activity, and the shaped materials beads were tested for their release in the gastrointestinal fluids. Through the analysis of various physico-chemical techniques, we observed the interactions between the studied materials, the formation of hybrids materials, obtaining the bionanocomposites materials and material efficiency when applied in controlled release of drugs both topical and use oral mainly influenced by the presence of zein, are promising as topical delivery systems and oral drugs.

Made available in DSpace on 2014-12-17T14:57:57Z (GMT). No. of bitstreams: 1 DanyGKCS_TESE.pdf: 7629414 bytes, checksum: 0319ec74d00ba690b4f1a60f7aab52d1 (MD5) Previous issue date: 2013-10-18 / Removing microcontaminants from effluents is a challenge today, because of its high cost and low efficiency, especially in the treatment of effluents containing heavy metals. An alternative that has emerged is the use of biodegradable nanocomposites, which exhibit good removal and recovery performances, in addition to its low cost. With this in mind, the present study aimed to develop and characterize a nanocomposite based on hydroxyapatite (HAP), polyurethane (PU) and polyvinyl alcohol (PVA) for removing heavy metals. Thus, the research was conducted in several steps: i)- Physico-chemical and microbiological hospital effluent characterization; ii)- Production of hydroxyapatite by aqueous precipitation technique, and their characterization; iii)- Production of the nanocomposite in which the hydroxyapatite was added to the polyurethane prepolymers and then the polyvinyl alcohol/hydroxyapatite film was produced; iv)- Polyvinyl composite without film PU/HAp was also produced in the proportions of 20 and 40% HAp; v)- The composites was characterized by the techniques of XRD, FTIR, SEM / EDS, BET, Zeta Potential and TGA; vi)- The sisal and coconut fibres were washed and dried for comparative tests of adsorption; vii)- Adsorption tests for evaluating the removal of heavy metals (nickel and cadmium). Initial screening adsorption capacity (HAp; PU/HAp - 20 and 40%; PU / HAp / PVA), kinetic studies of adsorption of Cd (II) by HAp; multifactorial design analysis (factorial design) for identifying the most important variables in the adsorption of Cd (II) by composite PU/HAp. Also comparative analysis of adsorption of Cd and Ni by composite PU/HAp were conducted, as well as comparative tests of adsorption of Cd (coconut fibre) and Ni (sisal fibre). It was possible to verify that the composite PU/HAp 40% showed better effectiveness for the removal of Cd (II) and Ni (II), above 80%, equivalent to the lignocellulosic fibre used and HAp produced. As main conclusion, it can be referred that the composite PU/HAp 40% is an effective adsorvent to wastewater treatment for heavy metal removal, with low cost and high efficiency / A remo??o de microcontaminantes, em especial no tratamento de efluentes contendo metais pesados, ? um desafio na atualidade, em decorr?ncia de seu elevado custo e baixa efici?ncia. Uma tecnologia que vem surgindo como promissora ? a aplica??o de nanocomp?sitos biodegrad?veis, a qual apresenta uma efici?ncia favor?vel de remo??o e recupera??o deste microcontaminante, al?m de seu baixo custo. Neste ?mbito, o presente estudo objetivou desenvolver e caracterizar um nanocomp?sito ? base de hidroxiapatita (HAP), poliuretano (PU) e ?lcool povinil?co (PVA) para remo??o de metais pesados. A investiga??o foi desenvolvida em v?rias etapas: i)- caracteriza??o f?sico-qu?mica e microbiol?gica de efluentes hospitalares, como potencial caso de estudo; ii)- produ??o de hidroxiapatita por meio da t?cnica de precipita??o aquosa, e respectiva caracteriza??o; iii)- produ??o de nanocomp?sito com revestimento, no qual a hidroxiapatita (HAp) foi adicionada aos pr?-pol?meros de poliuretano, e a pel?cula de ?lcool poliv?nilico e hidroxiapatita foi produzida e aderida ao comp?sito; iv)- produ??o de comp?sito n?o-peliculado PU/HAp nas propor??es a 20 e 40% de HAp; v)- caracteriza??o do comp?sito pelas t?cnicas de DRX, FTIR, MEV/EDS, BET, Potencial Zeta e TGA; vi)- tratamento f?sico-qu?mico da fibra de sisal e coco, como potenciais bioadsorventes de baixo custo utilizados em estudos comparativos; vii)- testes de adsor??o de metais pesados (n?quel e c?dmio). Neste ?mbito, foi realizada uma triagem inicial de capacidade de adsor??o da HAp, PU/HAp 20 e 40% e PU/HAp/PVA, envolvendo estudos cin?ticos de adsor??o de Cd (II). De modo a identificar as vari?veis mais importantes na adsor??o de Cd (II) pelo comp?sito PU/HAp, foi tamb?m considerado o desenho de experi?ncias (factorial design). Adicionalmente, este adsorvente (PU/HAp) foi tamb?m testado como adsorvente de Cd e Ni. Finalmente, foram realizados testes de adsor??o de Cd em fibras de coco, e de Ni em fibras de sisal. O estudo realizado permitiu concluir que o comp?sito PU/HAp 40% apresentou elevada efici?ncia na remo??o de Cd (II) e Ni (II), superiores a 80%, sendo equivalente ?s fibras lignocelul?sicas utilizadas e ? HAp produzida. Como principal conclus?o deste estudo, destaca-se o fato de que estes materiais podem ser utilizados no tratamento de efluentes para remo??o de metais pesados, dado que apresentam baixo e custo e elevada efici?ncia / 2020-01-01

Made available in DSpace on 2014-12-17T14:57:50Z (GMT). No. of bitstreams: 1 RannierMM.pdf: 3580955 bytes, checksum: f892200d861ab62414259c44c459e1b9 (MD5) Previous issue date: 2009-03-30 / The use of polymer based coatings is a promising approach to reduce the corrosion problem in carbon steel pipes used for the transport of oil and gas in the oil industry. However, conventional polymer coatings offer limited properties, which often cannot meet design requirements for this type of application, particularly in regard to use temperature and wear resistance. Polymer nanocomposites are known to exhibit superior properties and, therefore, offer great potential for this type of application. Nevertheless, the degree of enhancement of a particular property is greatly dependent upon the matrix/nanoparticle material system used, the matrix/nanoparticle interfacial bonding and also the state of dispersion of the nanoparticle in the polymer matrix. The objective of the present research is to develop and characterize polymer based nanocomposites to be used as coatings in metallic pipelines for the transportation of oil and natural gas. Epoxy/SiO2 nanocomposites with nanoparticle contents of 2, 4, and 8 wt % were processed using a high-energy mill. Modifications of the SiO2 nanoparticles‟ surfaces with two different silane agents were carried out and their effect on the material properties were investigated. The state of dispersion of the materials processed was studied using Scanning and Transmission Electron Microscopy (SEM and TEM) micrographs. Thermogravimetric analysis (TG) were also conducted to determine the thermal stability of the nanocomposites. In addition, the processed nanocomposites were characterized by dynamic mechanical analysis (DMA) to investigate the effect of nanoparticles content and silane treatment on the viscoelastic properties and on the glass transition temperature. Finally, wear tests of the pin-on-disc type were carried out to determine the effects of the nanoparticles and the silane treatments studied. According to the results, the addition of SiO2 nanoparticles treated with silane increased the thermal stability, the storage modulus and Tg of the epoxy resin and decreased wear rate. This confirms that the interaction between the nanoparticles and the polymer chains plays a critical role on the properties of the nanocomposites / A utiliza??o de pol?mero como revestimento ? algo promissor para redu??o de corros?o interna de dutos de a?o carbono utilizados no transporte de petr?leo e g?s natural na ind?stria petrol?fera. No entanto, os revestimentos polim?ricos convencionais apresentam propriedades limitadas, que muitas vezes n?o podem satisfazer os requisitos necess?rios, particularmente em rela??o ? temperatura empregada e ao desgaste. Nanocomp?sitos polim?ricos s?o conhecidos por apresentarem propriedades superiores e, portanto, apresentam potencial para este tipo de aplica??o. Por?m, o grau de refor?o de uma propriedade particular ? fortemente dependente dos materiais utilizados no sistema matriz/nanopart?culas, da liga??o interfacial e, tamb?m, do estado de dispers?o das nanopart?culas na matriz polim?rica. O objetivo do presente trabalho ? desenvolver e caracterizar nanocomp?sitos polim?ricos para utiliza??o como revestimento de dutos met?licos da ind?stria do petr?leo. Nanocomp?sitos Ep?xi/SiO2 com 2, 4 e 8% em massa de nanopart?culas foram processados usando um moinho de alta energia. Modifica??es nas superf?cies das nanopart?culas de SiO2 foram realizadas com dois tipos diferentes de silano e seus efeitos sobre as propriedades dos materiais foram investigados. O estado de dispers?o do material processado foi estudado usando micrografias de Microscopia Eletr?nica de Varredura e de Transmiss?o (MEV e MET). Foram realizadas an?lises termogravim?tricas (TG) para verificar a estabilidade t?rmica dos nanocomp?sitos. Al?m disso, foram realizadas an?lises din?mico-mec?nicas (DMA) para estudar os efeitos das nanopart?culas e dos tratamentos com silano nas propriedades viscoel?sticas e na temperatura de transi??o v?trea (Tg). Por fim, testes de desgaste do tipo esfera-disco foram realizados para determinar os efeitos da adi??o de nanopart?culas e dos diferentes tipos de tratamento de silaniza??o estudados. De acordo com os resultados, a adi??o nanopart?culas de SiO2 tratadas com silano aumentou a temperatura de in?cio de degrada??o do pol?mero, o m?dulo de armazenamento e a Tg da resina ep?xi, al?m de ter proporcionado uma menor taxa de desgaste. Isto confirma que a intera??o entre as nanopart?culas e as cadeias polim?ricas desempenha um papel cr?tico sobre as propriedades dos nanocomp?sitos

Made available in DSpace on 2014-12-17T14:07:16Z (GMT). No. of bitstreams: 1 EdnaMSC_DISSERT.pdf: 4754889 bytes, checksum: 7ba8ec4a5f3d11921ca74b85b2fe0b3b (MD5) Previous issue date: 2013-07-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This employment has the function the utilization of mango seeds Tommy Atkins, like starch source to obtain biopolymers and fibers source and nanowhiskers cellulose also, that will be use like reinforcing fillers in micro and nanobiocomposites polymeric. The fibers in natura removed from tegument mango seed were characterized, as weel as the treated fibers and nanowhiskers of cellulose extracted from them. The starch extracted from seed s almond showed a good performance (32%) and a high purity. The chemicals analyzes, of crystallinity and morphological of the fibers in natura, treated fibers and nanowhiskers of cellulose confirmed the efficacy of the chemical treatement performed to remove amorphous constituents (hemicellulose and lignina). The thermoplastic starch (TPS) obtained from two sources, corn starch and starchy material mango, was produced in a twin screw extruder with compositon mass of 62,5% of starch, 9,4% of water and 28,1% of glycerol. The starch material mango was the main objective of this work for the production of biodegradable materials, and the starch corn was utilized during the production stage to evaluate the processability of the starch and use as parameter for comparison, according of being a conventional source for obtaining conventional comercial starch. The incorporation of fibers (6% in mass) and nanowhiskers cellulose (1% in mass) in matrix of TPS to obtain composite and nanocomposite, respectively, it was performed in single screw extruder. The biocomposites and bionanocomposites polymeric were obtained and the TPS from starchy material mango presented better results of thermal and mechanicals properties when compared to TPS corn starch. Concludes that the sediment generated of the agroindustrial processing mango used presents potencial to producing of biodegradables materials / Este trabalho apresenta como objetivo a utiliza??o de caro?os da manga Tommy Atkins, como fonte de amido para obten??o de biopol?meros e, tamb?m, como fonte de fibras e nanowhiskers de celulose, que foram utilizadas como cargas refor?antes em micro e nanobiocomp?sitos polim?ricos. As fibras in natura removidas do tegumento do caro?o de manga foram caracterizadas, bem como as fibras tratadas e nanowhiskers de celulose extra?dos a partir delas. O amido extra?do das am?ndoas do caro?o apresentou um bom rendimento (32%) e elevado grau de pureza. As an?lises qu?micas, de cristalinidade e morfol?gicas das fibras in natura, fibras tratadas e nanowhiskers de celulose confirmaram a efic?cia do tratamento qu?mico realizado em remover os constituintes amorfos (hemicelulose e lignina). O amido termopl?stico (TPS) obtido de duas fontes, amido de milho e material amil?ceo de manga, foi produzido em extrusora rosca dupla com a composi??o em massa de 62,5% de amido, 9,4% de ?gua e 28,1% de glicerol. O material amil?ceo de manga foi o objetivo principal deste trabalho para produ??o de materiais biodegrad?veis, e o amido de milho foi utilizado durante a etapa de produ??o para avaliar a processabilidade do amido e utilizar como par?metro de compara??o, em fun??o de ser uma fonte convencional de obten??o de amido comercial. A incorpora??o das fibras (6% em massa) e nanowhiskers de celulose (1% em massa) em matriz de TPS para obter comp?sitos e nanocomp?sitos, respectivamente, foi realizada em extrusora monorosca. Os biocomp?sitos e bionanocomp?sitos polim?ricos foram obtidos e os TPS do material amil?ceo de manga apresentaram melhores resultados de propriedades t?rmicas e mec?nicas quando comparados aos TPS de amido de milho. Concluiu-se que os res?duos gerados do processamento agroindustrial da manga utilizados apresentaram potencial para a produ??o de materiais biodegrad?veis