Thesis (M.S.)--Florida State University, 2005. / Advisor: Zhiyong Liang, Florida State University, College of Engineering, Dept. of Industrial Engineering. Title and description from dissertation home page (viewed Jan. 12, 2005). Document formatted into pages; contains xiv, 136 pages. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 77-98).

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Douglas J. Doren, Dept. of Chemistry and Biochemistry. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references and index.

No description available.

In the recent past, graphene has been discovered and studied as one of the most promising materials after silicon and carbon nanotube. Its atomically thin structure, pristine dangling bonds free surface and interface, ultra-fast charge transport capability, semi-metallic behavior, ultra-strong mechanical ruggedness, promising photonic properties and bio-compatibility makes it a material to explore from all different perspectives to identify potential application areas which can augment the quality of our life. Therefore, in this doctoral work the following critical studies have been carried out meticulously with key findings are listed below: (1) A simplistic and sustainable growth process of double or multi-layer graphene (up to 4” substrate coverage with uniformity) using low-cost atmospheric chemical vapor deposition (APCVD) technique. [presented in MRS Fall Meeting 2012 and in IEEE SIECPC 2012) (2) A buried metallic layer based contact engineering process to overcome the sustained challenge of contact engineering associated with low-dimensional atomically thin material. (presented in IEEE Nano 2013 and archieved in conference proceedings) (3) Demonstration of a fin type graphene transistor (inspired by multi-gate architecture) with a mobility of 11,000 cm2/V.s at room temperature with an applied drive-in voltage of ±1 volt to demonstrate for the first time a pragmatic approach for graphene transistor for mobile applications which can maintain its ultra-fast charge transport behavior with ultra-low power consumption. [Published in ACS Nano 2013] (4) Further a meticulous study has been done to understand the harsh environment compatibility of graphene for its potential use in underwater and space applications. [Published as Cover Article in physica solidi status – Rapid Research Letters, 2014] (5) Due to its highly conductive nature and low surface-to-volume ratio it has been used to replace conventional gold based anodic material in microbial fuel cells (used for water purification in self-sustained mode) to demonstrate its effectiveness as a sustainable low-cost mechanically robust transparent material. [Published in ACS Nano 2013, in Energy Technology 2014 as a Cover Article and in Nature Publishing Group Asia Materials 2014] (6) Extensive study to stabilize graphene surface and to use the phenomena for development of a sensor which can monitor the quality of water. [presented in MRS Fall Meeting 2013 and in MRS Fall Meeting 2014] (7) By using graphene as an expose transistor architecture with ultra-scale high-k dielectric, to develop a series of sensor for glucose monitoring. Sensitivity, selectivity, response rate and refresh time has been studied and optimized. [pending review in Nature Scientific Reports 2015] (8) From the lessons learnt during the development of glucose monitoring sensor cell, a sophisticated low-cost ultra-low power mobile graphene based non-invasive sensor has been assembled and clinically trialed in collaboration with King Faisal Hospitals in Jeddah and in Makkah. [pending review in Science 2015] As a future direction, this thesis also discusses potential of graphene growth on electrochemically deposited metallic seed layers and consequential usage in stretchable and transparent graphene antenna development for fully flexible only graphene based integrated electronic system integration.

Orientador: Alexandre Mesquita / Banca: Giovani Fornereto Gozzi / Banca: Waldir Avansi Junior / Resumo: Nos últimos anos, o estudo de materiais cerâmicos vem evoluindo muito rapidamente, principalmente os estudos relacionados com cerâmicas avançadas. As diversas aplicações envolvendo esses materiais, tais como pigmentos cerâmicos com partículas nanométricas, justificam cada vez mais a necessidade de uma melhor compreensão da influência da adição de dopantes nas propriedades finais dos materiais. No presente trabalho propõe-se analisar e estudar as propriedades estruturais e morfológicas de pigmentos cerâmicos a base de óxido de cério (CeO2) e dopados com diferentes porcentagens molares de lantânio (5 e 10%) e praseodímio (1%). Um dos principais objetivos foi obter pigmentos cerâmicos com tamanho de partícula nanométrico de baixa toxicidade. O processo químico adotado para a obtenção dos pós foi o método dos precursores poliméricos. As nanopartículas foram estruturalmente caracterizadas por difração de raios X (DRX), espectroscopia Raman e espectroscopia de absorção de raios X (XAS). A forma e o tamanho das nanopartículas foram observados por intermédio da microscopia eletrônica de varredura (MEV). A caracterização óptica foi realizada utlizando-se dos resultados de reflectância difusa para obtenção das coordenadas colorimétricas. Os padrões de DRX e espectros Raman indicam a formação de soluções sólidas cristalinas monofásicas com estrutura cúbica do tipo fluorita, pertencentes ao grupo espacial Fm3m. O tamanho dos grãos foi da ordem de 20 a 30 nanômetros, como estimado por MEV. Por reflectância difusa e coordenadas colorimétricas foi determinado que as amostras de CeO2 e CL (óxido de cério dopado com lantânio) possuem coloração amarela enquanto as amostras CLP (óxido de cério dopado com lantânio e praseodímio) e CP (óxido de cério dopado com praseodímio) possuem coloração que varia do ... (Resumo completo, clicar acesso eletrônico abaixo) / Abastract: In the last few years, the study of ceramic materials has increased very fast, mainly studies related to advanced ceramics. The several applications of these materials as ceramic pigments in nanometric scale justify more and more the need for a better understanding of the influence of the dopant addition on the final properties of the materials. In this present work, it was studied structural and morphological properties of ceramic pigments based on cerium oxide (CeO2) and doped with differents molar percentages of lanthanum (5 and 10%) and praseodymium (1%). The goal of this work was to obtain nanosized ceramic pigments with a low-toxicity. The chemical route adopted to obtain materials was the polymeric precursor method. The nanoparticles were structurally characterized by X-Ray Diffraction (XRD), Raman Spectroscopy, Scanning Electron Microscopy (SEM) and X-Ray absorption spectroscopy (XAS). Optical characterization was carried out using the results of diffuse reflectance to obtain the colorimetric coordinates. The XRD patterns and Raman spectra indicate the formation of crystalline solid solutions with single phase and cubic structure (fluorite), all belongs to the space group Fm3m. The obtained grain size was in nanoscale range, 20 to 30 nm, according to MEV. By diffuse reflectance tecnique and colorimetric coordinates were verified that the CeO2 and CL (cerium oxide doped with lanthanum) samples possess yellow coloration and the CLP (cerium oxide doped with lanthanum and praseodymium) and CP (cerium oxide doped with praseodymium) samples present coloration that varies from magenta-orange to red-brown. More intense shades were obtained in pigments doped with praseodymium at 800 ºC temperature / Mestre

abstract: In the last few years, significant advances in nanofabrication have allowed tailoring of structures and materials at a molecular level enabling nanofabrication with precise control of dimensions and organization at molecular length scales, a development leading to significant advances in nanoscale systems. Although, the direction of progress seems to follow the path of microelectronics, the fundamental physics in a nanoscale system changes more rapidly compared to microelectronics, as the size scale is decreased. The changes in length, area, and volume ratios due to reduction in size alter the relative influence of various physical effects determining the overall operation of a system in unexpected ways. One such category of nanofluidic structures demonstrating unique ionic and molecular transport characteristics are nanopores. Nanopores derive their unique transport characteristics from the electrostatic interaction of nanopore surface charge with aqueous ionic solutions. In this doctoral research cylindrical nanopores, in single and array configuration, were fabricated in silicon-on-insulator (SOI) using a combination of electron beam lithography (EBL) and reactive ion etching (RIE). The fabrication method presented is compatible with standard semiconductor foundries and allows fabrication of nanopores with desired geometries and precise dimensional control, providing near ideal and isolated physical modeling systems to study ion transport at the nanometer level. Ion transport through nanopores was characterized by measuring ionic conductances of arrays of nanopores of various diameters for a wide range of concentration of aqueous hydrochloric acid (HCl) ionic solutions. Measured ionic conductances demonstrated two distinct regimes based on surface charge interactions at low ionic concentrations and nanopore geometry at high ionic concentrations. Field effect modulation of ion transport through nanopore arrays, in a fashion similar to semiconductor transistors, was also studied. Using ionic conductance measurements, it was shown that the concentration of ions in the nanopore volume was significantly changed when a gate voltage on nanopore arrays was applied, hence controlling their transport. Based on the ion transport results, single nanopores were used to demonstrate their application as nanoscale particle counters by using polystyrene nanobeads, monodispersed in aqueous HCl solutions of different molarities. Effects of field effect modulation on particle transition events were also demonstrated. / Dissertation/Thesis / Ph.D. Electrical Engineering 2011

Orientadora: Maria del Pilar Taboada Sotomayor / Coorientador: Marcos Vinicius Foguel / Banca: Hideko Yamanaka / Banca: Ivo Milton Raimundo Junior / Resumo: O desenvolvimento de métodos analíticos com maior seletividade e sensibilidade tem ampla importância para a determinação de diferentes compostos químicos. O emprego de polímeros molecularmente impressos, do inglês "Molecularly Imprinted Polymers" (MIP), que são obtidos por polimerização na presença de uma molécula molde (template) a ser impressa, de tal forma que um esqueleto polimérico é formado ao redor do. No caso deste trabalho, o template utilizado foi a ciprofloxacina, antibiótico amplamente empregado no tratamento de doenças de seres humanos e animais. Desta maneira foi realizado a síntese das nanopartículas magnéticas de óxido de ferro, pelo método de co-precipitação, estas foram recobertas com MIP em sua superfície, formando assim um material híbrido do tipo Core-Shell. Foram realizadas duas sínteses distintas, sendo um primeiro MIP utilizando apenas o ácido acrílico como monômero funcional (Mag-MIP1), e um segundo MIP tendo em sua estrutura o ácido acrílico e o 1-vinilimidazol como monômeros funcionais (Mag-MIP2). Os materiais foram caracterizados fisicamente por diferentes técnicas. Foram realizados experimentos de otimização do Mag-MIP1 e Mag-MIP2, foi observado que o Mag-MIP1 exibiu um tempo ótimo de interação de 120 min em meio aquoso, enquanto que o Mag-MIP2 apresentou um tempo ótimo de interação de 30 min em meio de água/metanol (70:30) v/v. No que se refere ao parâmetro de seletividade, o Mag-MIP2 exibiu um valor de seletividade (S) ≥ 2, enquanto que o Mag-MI... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The development of analytical methods with greater selectivity and sensitivity is of great importance for the determination of different chemical compounds. The use of molecularly imprinted polymers (Molecularly Imprinted Polymers) (MIP), which are obtained by polymerization in the presence of a template molecule to be printed, such that a polymeric backbone is formed around the polymer. In the case of this w ork, the template used was ciprofloxacin, an antibiotic widely used in the treatment of diseases of humans and animals. In this way the synthesis of iron oxide magnetic nanoparticles was performed by the co - precipitation method, these were covered with MIP on their surface, forming a hybrid material of the Core - Shell type. Two distinct syntheses were performed, a first MIP using only acrylic acid as a functional monomer (Mag - MIP1), and a second MIP having acrylic acid and 1 - vinylimidazole as functional mono mers (Mag - MIP2). The materials were physically characterized by different techniques. Mag - MIP1 and Mag - MIP2 optimization experiments were performed, Mag - MIP1 showed an optimal interaction time of 120 min in aqueous medium, while Mag - MIP2 showed an optimal interaction time of 30 min in water / methanol (70:30) v / v medium. As for the selectivity parameter, the Mag - MIP2 exhibited a selectivity value (S) ≥ 2, while the Mag - MIP1 presented values of S ≥ 1 . The materials developed were applied as extractive phase dispersion in samples of bovine milk ... (Complete abstract click electronic access below) / Mestre