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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

S?ntese e imobiliza??o de nanopart?culas de ouro em fibras regeneradas via exaust?o para potencial aplica??o biom?dica

Silva, Iris Oliveira da 20 February 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T19:01:20Z No. of bitstreams: 1 IrisOliveiraDaSilva_DISSERT.pdf: 2857420 bytes, checksum: 79699f54a821e014e634ecb96cbf1212 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-28T21:28:52Z (GMT) No. of bitstreams: 1 IrisOliveiraDaSilva_DISSERT.pdf: 2857420 bytes, checksum: 79699f54a821e014e634ecb96cbf1212 (MD5) / Made available in DSpace on 2016-01-28T21:28:53Z (GMT). No. of bitstreams: 1 IrisOliveiraDaSilva_DISSERT.pdf: 2857420 bytes, checksum: 79699f54a821e014e634ecb96cbf1212 (MD5) Previous issue date: 2015-02-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O avan?o nanotecnol?gico na s?ntese e caracteriza??o de nanopart?culas (NP?s) tem protagonizado o desenvolvimento de novas tecnologias para diversas aplica??es de materiais em escala nanom?trica que apresentam propriedades especificas. O desenvolvimento cient?fico nas ?ltimas d?cadas na ?rea de nanotecnologia tem protagonizado a descoberta de novos materiais para as mais diversas aplica??es, em ?reas como: biom?dicas, qu?mica, ?ptica, mec?nica e t?xtil. A alta efici?ncia bactericida de nanopart?culas met?licas (Au e Ag), dentre outros metais ? bastante conhecida, devido a sua capacidade de agir no DNA de fungos, v?rus e bact?rias, interrompendo o processo de respira??o celular, tornando-os importantes meios de estudo, al?m de sua capacidade de prote??o UVA e UVB. Este trabalho tem como objetivo principal a aplica??o de um m?todo inovador na impregna??o de nanopart?culas de ouro em substrato t?xtil, funcionalizado com quitosana, pelo processo de tingimento via exaust?o, com controle de temperatura, tempo e velocidade e obten??o de caracter?sticas antimicrobianas e prote??o UV. Os substratos esgotados com solu??es coloidais de NPAu?s apresentaram colora??o lil?s e avermelhada (em malha de soja) devido a sua superf?cie de plasmon no pico em torno de 520-540 nm. As NPAu?s foram sintetizadas via s?ntese qu?mica, usando o citrato de s?dio como agente redutor e estabilizador. O material foi previamente cationizado com quitosana, um polieletr?lito natural, com a finalidade de funcionaliz?-lo para potencializar a adsor??o das NPAu, sendo usadas concentra??es de 5, 7, 10 e 20 % de ligante sobre o peso do material (SPM). Verificou-se tamb?m, atrav?s de um planejamento experimental 23 , com 3 pontos centrais, qual era o melhor processo de esgotamento dos substratos, utilizando os fatores: tempo (min.), temperatura (?C) e concentra??o do coloide (%), tendo como resposta a vari?vel for?a color?stica - K/S (KubelkaMunk) das fibras. Foram evidenciadas como melhores respostas os par?metros: concentra??o e temperatura. O substrato com NPAu foi caracterizado por DRX; An?lise t?rmica, via TGA; microestrutural via MEV/EDS evidenciando as NP na superf?cie do substrato e presen?a de ouro (Au). Observou-se tamb?m que os substratos funcionalizados com NPAu possuem boa solidez a lavagem, fator de classifica??o UPF de +50, considerado excelente e propriedade bactericida de 98,22% para staphylococcus aureus e 96,45% para klebsiella pneumoniae, comprovando que o tecido multifuncional desenvolvido, possui grande potencial de aplica??o na ?rea biom?dica / The advancement of nanotechnology in the synthesis and characterisation of nanoparticles (NP's) has played an important role in the development of new technologies for various applications of nano-scale materials that have unique properties. The scientific development in the last decades in the field of nanotechnology has sought ceaselessly, the discovery of new materials for the most diverse applications, such as biomedical areas, chemical, optical, mechanical and textiles. The high bactericidal efficiency of metallic nanoparticles (Au and Ag), among other metals is well known, due to its ability to act in the DNA of fungi, viruses and bacteria, interrupting the process of cellular respiration, making them important means of study, in addition to its ability to protect UVA and UVB. The present work has as its main objective the implementation of an innovative method in the impregnation of nanoparticles of gold in textile substrate, functionalized with chitosan, by a dyeing process by exhaustion, with the control of temperature, time and velocity, thus obtaining microbial characteristics and UV protection. The exhausted substrates with colloidal solutions of NPAu's presented the colours, lilac and red (soybean knits) due to their surface plasmon peak around 520-540 nm. The NPAu's were synthesized chemically, using sodium citrate as a reducing agent and stabilizer. The material was previously cationised with chitosan, a natural polyelectrolyte, with the purpose of functionalising it to enhance the adsorption of colloid, at concentrations of 5, 7, 10 and 20 % of the bonding agent on the weight of the material (OWM). It was also observed, through an experimental design 23 , with 3 central points, which was the best process of exhaustion of the substrates, using the following factors: Time (min.), temperature (OC) and concentration of the colloid (%), having as a response to variable K/S (ABSORB?NCIA/ Kubelka-Munk) of the fibres. Furthermore, it was evidenced as the best response, the following parameters: concentration 100%, temperature 70 ?C and time 30 minutes. The substrate with NPAu was characterised by XRD; thermal analysis using TGA; microstructural study using SEM/EDS and STEM, thus showing the NP on the surface of the substrate confirming the presence of the metal. The substrates showed higher washing fastness, antibacterial properties and UV radiation protection.

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