Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-01-15T21:40:48Z No. of bitstreams: 1 MariaAugustaCavalcantiSoares_DISSERT.pdf: 3097668 bytes, checksum: e79dcba5d529592b21331e686931f1c1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-01-17T14:51:17Z (GMT) No. of bitstreams: 1 MariaAugustaCavalcantiSoares_DISSERT.pdf: 3097668 bytes, checksum: e79dcba5d529592b21331e686931f1c1 (MD5) / Made available in DSpace on 2018-01-17T14:51:17Z (GMT). No. of bitstreams: 1 MariaAugustaCavalcantiSoares_DISSERT.pdf: 3097668 bytes, checksum: e79dcba5d529592b21331e686931f1c1 (MD5) Previous issue date: 2016-12-19 / Nos ?ltimos anos o desenvolvimento de supercapacitores tem sido bastante pesquisado devido ? propriedade de possuir densidade de pot?ncia maior do que as baterias convencionais. Para atender as demandas tecnol?gicas da sociedade moderna, a cria??o de dispositivos de armazenamento de energia leves, flex?veis e port?teis, tamb?m chamados de supercapacitores flex?veis, est?o sendo estudados. Os nanotubos de carbono (CNTs ? Carbon nanotubes) incrementam propriedades especiais aos substratos t?xteis, tais como, melhoramento da condutividade el?trica e antiest?tica, aumento da durabilidade e condutividade/isolamento de calor e podem ser aplicados em diversas ?reas, podendo atuar como fornecedores de energia para dispositivos de monitoramentos biom?dicos ou implantes, equipamentos militares e para a constru??o civil. O presente trabalho tem como principal objetivo na forma??o de supercapacitores flex?veis utilizando um m?todo para prepara??o e modifica??o dos nanotubos de carbono de m?ltiplas camadas (MWCNT ? Multiwalled carbon nanotubes) para posterior impregna??o sobre substrato t?xtil de soja. A primeira etapa deste trabalho teve o objetivo de avaliar ? forma??o de grupos funcionais na estrutura dos MWCNTs para sua dispers?o em ?gua atrav?s da funcionaliza??o com diferentes ?cidos (H2SO4 ? ?cido sulf?rico e HNO3 ? ?cido n?trico), sendo purificados com HCl (?cido clor?drico) e neutralizados com NH4OH (hidr?xido de am?nio). Na segunda etapa este material foi funcionalizado com quitosana afim de cationizar os MWCNT e potencializar sua adsor??o sobre a malha de soja. Ap?s o estabelecimento dos par?metros adequados, foram analisadas as diferentes concentra??es de MWCNTs (0%, 1,0%, 2,0% e 3,0% sob peso do material funcionalizado), para a identifica??o do melhor resultado. As t?cnicas de caracteriza??o utilizadas comprovaram que o processo de funcionaliza??o ?cida foi satisfat?rio por promover a aberturas dos tubos dos MWCNTs, sendo identificadas atrav?s da Microscopia Eletr?nica de Transmiss?o (MET) e por facilitar a sua solubilidade em meio aquoso observados de acordo com a Espectroscopia de Absor??o UV-vis, al?m de diminuir a quantidade de impurezas met?licas constatadas em Fluoresc?ncia Raio X (FRX). Os efeitos da funcionaliza??o dos MWCNTs foram comprovados em Difra??o Raio X (DRX) e Espectroscopia Raman. A perda de massa do material identificada por An?lise Termogravim?trica (TG) mostra o aumento ap?s a funcionaliza??o. O processo de imobiliza??o dos nanotubos de carbonos sobre as fibras de soja foi comprovado via Microscopia Eletr?nica de Varredura (MEV), bem como, por an?lises eletroqu?micas que determinaram a forma??o de supercapacitores com maior capacit?ncia espec?fica, de 0,766 mF.cm-2, a uma concentra??o de 3,0%, com caracter?sticas t?xteis favor?veis. / In recent years the development of supercapacitors have been searched because of the property of possessing power density greater than conventional batteries. To meet the technological demands of modern society, the creation of energy storage devices, flexible and lightweight laptops, also called flexible supercapacitors are being studied. Carbon nanotubes (CNTs) increment special properties to textile substrates, such as, improving the electrical conductivity and antistatic, increased durability and heat insulation/conductivity and can be applied in various areas, and may act as energy suppliers for Biomedical monitoring devices or implants, military equipment and civil construction. The present work has as main objective in the formation of flexible supercapacitors using a method for preparation and modification of multiwall carbon nanotubes (MWCNT) for subsequent immobilization on soybean protein textile fabric. The first stage of this work corresponds to the formation of functional groups in the structure of MWCNTs for their dispersion in water through the functionalization with different acids (H2SO4 - sulfuric acid and HNO3 - nitric acid), being purified with HCl (hydrochloric acid) and neutralized with NH4OH (ammonium hydroxide). In the second step the material was functionalized with chitosan in order to cationize the MWCNT and potentiate its adsorption in soybean mesh. After establishing the appropriate parameters, different concentrations of MWCNTs (0%, 1.0%, 2.0% and 3.0% under weight of the functionalized material) were analyzed to identify the best result. The characterization techniques used proved that the acid functionalisation process was satisfactory for promoting the openings of the MWCNTs tubes, being identified by Transmission Electron Microscopy (TEM) and for facilitating their solubility in aqueous media observed in accordance with the Spectroscopy of UV-vis absorption, besides decreasing the amount of metallic impurities found in X-ray Fluorescence (XRF).The effect of the functionalization of MWCNTs was confirmed in X-ray Diffraction (XRD) and Raman Spectroscopy. The loss of mass of the material identified by Thermogravimetric Analysis (TG) shows the increase after the functionalization. The process of immobilization of the nanoparticles in the soybean substrate showed characteristic nanofilaments of the assembly of the MWCNTs on the surface of the samples visualized in Scanning Electron Microscopy (SEM), as well as, the electrochemical analyzes determined the formation of supercapacitors with greater specific capacitance of 0.766 mF.cm-2, at a concentration of 3.0%, with favorable textile characteristics.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-09T23:24:53Z No. of bitstreams: 1 ChristianeSiqueiraDeAzevedoSa_DISSERT.pdf: 2601824 bytes, checksum: 192560f3b8d14a03aa0da8a4f6dc9924 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-11T22:01:19Z (GMT) No. of bitstreams: 1 ChristianeSiqueiraDeAzevedoSa_DISSERT.pdf: 2601824 bytes, checksum: 192560f3b8d14a03aa0da8a4f6dc9924 (MD5) / Made available in DSpace on 2016-03-11T22:01:19Z (GMT). No. of bitstreams: 1 ChristianeSiqueiraDeAzevedoSa_DISSERT.pdf: 2601824 bytes, checksum: 192560f3b8d14a03aa0da8a4f6dc9924 (MD5) Previous issue date: 2015-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Os materiais t?xteis inteligentes e funcionais t?m sido amplamente desenvolvidos e pesquisados com a finalidade de serem utilizados em v?rias ?reas da ci?ncia e tecnologia. Esses materiais fibrosos necessitam de diferentes propriedades qu?micas e f?sicas para se tornarem materiais multifuncionais. Com o advento da nanotecnologia, as t?cnicas desenvolvidas t?m sido ferramentas essenciais para caracterizar qualitativamente esses novos materiais. Ultimamente a aplica??o de micro e nanomateriais em substratos t?xteis tem sido objeto de muitas pesquisas. Muitos desses nanomateriais n?o tem sido otimizado, e os custos para sua aplica??o e a polui??o ao meio ambiente vem aumentando, pois ainda n?o existe tratamento de efluentes contento esses nanomateriais. As fibras de soja t?m baixa adsor??o de micro e nanoc?psulas termosenss?veis devido a sua incompatibilidade de suas cargas superficiais. No presente trabalho utilizou-se a s?ntese da quitosana para previamente funcionalizar as fibras de soja. A quitosana ? um polieletr?lito natural apresentando alta densidade de cargas positivas, as fibras de soja apresentam cargas negativas bem como, as micro/nanoc?psulas, com isso a quitosana atua como agente cationizador da fibra. Neste caso a quitosana atua como agente auxiliar cationizador para fixar as microc?psulas termosenss?veis no substrato t?xtil. Para a caracteriza??o do polieletr?lito foram feitas as an?lises do tamanho das part?culas, potencial zeta, bem como as an?lises morfol?gicas (MEV e DRX), an?lises das propriedades t?rmicas (TG), an?lise da Calorimetria Explorat?ria Diferencial (DSC), an?lise por Espectroscopia na Regi?o do Infravermelho com Transformada de Fourier (FTIR), colorimetria via espectro de UV-VIS foram simultaneamente realizadas no substrato utilizado. No potencial zeta e na determina??o do tamanho das part?culas foi observada a estabilidade eletrost?tica da quitosana em torno de 31.55mV e 291,0 nm respectivamente. O resultado obtido com (GD) para o material extra?do de camar?o foi de 70%, que de acordo com a literatura pode ser considerada como quitosana. Para otimiza??o do processo de tingimento foi usado um software estat?stico, o Design expert. A funcionaliza??o do substrato t?xtil com 2% de quitosana apresentou o melhor resultado de K/S, sendo o par?metro utilizado para o planejamento experimental juntamente com as vari?veis, tendo demonstrado a melhor resposta de tingimento na faixa de 2,624 de absorb?ncia. Verificou-se tamb?m que a malha de soja tingida com as nano/microc?psulas termosenss?veis apresentou excelente propriedade de solidez a lavagem, que foi observada ap?s 25 lavagens caseiras e valores significativos de K/S. / Intelligent and functional Textile Materials have been widely developed and researched with the purpose of being used in several areas of science and technology. These fibrous materials require different chemical and physical properties to obtain a multifunctional material. With the advent of nanotechnology, the techniques developed, being used as essential tools to characterize these new materials qualitatively. Lately the application of micro and nanomaterials in textile substrates has been the objective of many studies, but many of these nanomaterials have not been optimized for their application, which has resulted in increased costs and environmental pollution, because there is still no satisfactory effluent treatment available for these nanomaterials. Soybean fiber has low adsorption for thermosensitive micro and nanocapsules due to their incompatibility of their surface charges. For this reason, in this work initially chitosan was synthesized to functionalise soybean fibres. Chitosan is a natural polyelectrolyte with a high density of positive charges, these fibres have negative charges as well as the micro/nanoc?psules, for this reason the chitosan acts as auxiliary agent to cationize in order to fix the thermosensitive microcapsules in the textile substrate. Polyelectrolyte was characterized using particle size analyses and the measurement of zeta potential. For the morphological analysis scanning Electron Microscopy (SEM) and x-Ray Diffraction (XRD) and to study the thermal properties, thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Near Infrared Spectroscopy analysis in the Region of the Fourier Transform Infrared (FTIR), colourimetry using UV-VIS spectrum were simultaneously performed on the substrate. From the measurement of zeta potential and in the determination of the particle size, stability of electrostatic chitosan was observed around 31.55mV and 291.0 nm respectively. The result obtained with (GD) for chitosan extracted from shrimp was 70 %, which according to the literature survey can be considered as chitosan. To optimize the dyeing process a statistical software, Design expert was used. The surface functionalisation of textile substrate with 2% chitosan showed the best result of K/S, being the parameter used for the experimental design, in which this showed the best response of dyeing absorbance in the range of 2.624. It was noted that soy knitting dyed with the thermosensitive micro andnanocapsules property showed excellent washing solidity, which was observed after 25 home washes, and significant K/S values.