English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/42462
logo share SHARE   Add this article to your Mendeley library MendeleyBASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

DC FieldValueLanguage
dc.contributor.advisorGómez-Romero, P.-
dc.contributor.advisorMuñoz-Rojas, David-
dc.contributor.authorAyyad, Omar-
dc.description238 páginas.-- Tesis presentada por D. Omar Daud Hasan Ayyad para optar al grado de Dr. en Ciencias Químicas siendo la tutora la Dra. Núria Llorca-Isern, el supervisor el Dr. Pedro Gómez-Romero y co-supervisor el Dr. David Muñoz-Rojas.es_ES
dc.description.abstractMetal nanoparticles embedded in host polymers have gained significant interest in recent years. These materials exhibit unique electrical, optical, and/or mechanical properties making them valuable for applications in many areas. Furthermore, the embedding of nanoscopic metals in polymer matrices is one of the easiest and most convenient way for metallic nanoparticles/nanostructures stabilization and handling process. The objectives of this thesis research focus on synthesis of silver nanoparticles and nanostructures within various types of polymer matrices. Article one presents three different methods for the synthesis of silver-agar hybrid materials through in-situ approach. This development substantially simplifies the nanocomposite synthesis by eliminating the need for any additional organic reducing or capping agents, which was previously used to stabilize the produced nanoparticles and to suppress their continuing growth. With the appropriate synthetic parameters, one can achieve silver nanoparticles or nanostructures by changing the reaction conditions and modifying the fabrication method. Article two describes a simple technique for the preparation of highly concentrated agar gel networks. The resulted gel networks exhibit greater compactness, smaller size porosity and higher mechanical strength in comparison with low concentration agar gels prepared hydrothermally, or with the gels of agar prepared conventionally. These highly concentrated agar gels can widen the possible applications of this widely used biocompatible polysaccharide. Article three introduces a novel strategy for the fabrication of silver nanostructures coated with polypyrrole polymer by using a relatively low reduction potential solid silver oxide as a metal precursor. The silver nanosnakes coated with PPy polymer are fabricated through in-situ approach by hydrothermal method. The pyrrole monomer serving as the reducing agent, while it s oxidized form, PPy polymer, enforcing preferential orientation of the produced metallic silver within the matrix that gives snake nanostructures core. Also, the PPy polymer functions as a stabilizing and protecting agent for the fabricated nanosnakes. The silver snake nanostructures are obtained by fine-tuning the synthetic parameters such as Ag:Py ratio, time and temperature of synthesis reaction. The resulting Ag@PPy core-shell nanostructures are prepared by a simple one-pot reaction, and the peculiar singe crystal silver nanosnake core is obtained without using any additional capping, stabilizing or assistant agent. In Article 4, the growth mechanism of Ag@PPy nanosnakes is investigated. The effect of different preparative experimental parameters on the formation of the peculiar Ag-PPy core-shell nanostructures is carefully studied. The Ag2O agglomerates coated with PPy film is the initial main product obtained before any hydrothermal treatment. The thermal activation of this composite mixture by heating it hydrothermally cause the formation of silver-PPy agglomerates, which in turn evolve with time to give Ag-PPy core-shell nanostructures as the main product. The presence of the PPy matrix plays a key role in the formation of the single crystal silver nanosnake core. The mobility of the metallic silver produced is limited by the surrounding PPy matrix.es_ES
dc.description.abstractThis limited mobility slows down the fusing process of the silver aggregated particles together and give them the opportunity to orient themselves due to the assembly process and to produce the peculiar silver-PPy coreshell nanosnakes through oriented attachment growth mechanism. In article five, growth constrains are imposed by an interfacial reaction rather than a polymer matrix. The synthesis and self-assembly of monodispersed Ag nanoparticles is accomplished by a hydrothermal two-compartment set up. This novel stategy yields a golden colored, 2-D array of naked and monodispersed silver nanoparticles formed on the aqueous solution surface without the aid of any additional surface modifying agents to stabilize the nanoparticles or to direct their self-assembly.es_ES
dc.description.sponsorshipI appreciate the financial support from the Palestinian Ministry of Higher Education (Saudi Committee for the Relief of the Palestinian People) throughout my study. I would also like to thank the Agencia Española de Cooperación Internacional (AECI) for their financial support during the first year of my Ph.D study. I gratefully acknowledge the financial support, as a loan, from Al-Quds University, represented by its president Prof. Sari Nusseibeh, during the whole period of my study abroad.es_ES
dc.publisherUniversidad de Barcelonaes_ES
dc.publisherCSIC-ICN Centro de Investigación en Nanociencia y Nanotecnología (CIN2)es_ES
dc.titleNovel strategies for the synthesis of metal nanoparticles and nanostructureses_ES
dc.typetesis doctorales_ES
dc.description.peerreviewedPeer reviewedes_ES
Appears in Collections:(CIN2) Tesis
Files in This Item:
File Description SizeFormat 
PhD Tesis O.Ayyad.pdf13,83 MBAdobe PDFThumbnail
Show simple item record

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.