Orientador: Varlei Rodrigues / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-28T03:02:40Z (GMT). No. of bitstreams: 1 Rodrigues_KevinLiu_M.pdf: 15717954 bytes, checksum: 0231043634d153e2ddc45e00a8630aaa (MD5) Previous issue date: 2015 / Resumo: O estudo de nanopartículas é desafiador devido à complexidade destes sistemas, que estão na interface entre o pequeno e o grande. A física dos sólidos deixa de valer em muitas das partículas menores devido ao alto grau de confinamento, e a fração de átomos de superfície para átomos no núcleo. Devido à natureza pequena dos \textit{clusters}, as medidas realizadas nestes sistemas são medidas de alto grau de precisão. Com o objetivo de caracterizar feixes de fontes de agregados de maneira rápida e acessível, um circuito capacímetro é utilizado para medir a influência da deposição de nanopartículas na região dielétrica de um capacitor, uma proposta em aberto na área de nanopartículas. Como essa medida captura a contribuição de inúmeros agregados diferentes, todos depositados na região dielétrica do capacitor, um filtro seletor de massas pode ser utilizado para estreitar a largura da distribuição de tamanhos e obter a influência causada por esse tamanho específico apenas. Neste trabalho será apresentado o projeto para a implementação de um filtro com esse propósito, original de Issendorf e Palmer, cujo princípio de operação é o tempo de voo das partículas, e tem resolução esperada de uma parte em quarenta. Medidas de capacitância também foram realizadas na tentativa de caracterizar a variação da capacitância em função da quantidade de material depositado, com resultados promissores, mas que requerem um maior refinamento das medidas. Os nanoagregados foram produzidos depositados e analisados no Grupo de Física de Nanossistemas e Materiais Nanoestruturados (GFNMN) da física da Unicamp / Abstract: The study of nanoparticles is a challenging one because of the complexity of these systems, which lie on the interface between the small and the big. By that it is meant that many crystals and solids approximations cease to work, and confinement effects begin to appear, as well as surface phenomena which gain strength as surface to volume atoms increase. Due to the small particle sizes, measurements become increasingly difficult, requiring higher and higher precision techniques. With the objective of quickly characterizing beams produced by nanoaggregates sources, a capacitance measuring circuit was created with the intent of measuring the influence of the aggregates on the dielectric constant of the medium between the electrodes, a technique which has not been applied to cluster beams yet. In combination with the capacitance measurements, a mass selecting device was built in order to make the capacitance measurements reflect only a narrow mass distribution, allowing the study of properties of a single cluster size provided they are small enough. In this study will be discussed the project for such a mass filter, original by Issendorf and Palmer, and its implementation on a cluster source. Its principle of operation is the time of flight mass spectrometry, and its projected resolution of about one part in forty. Capacitance measurements were also performed to try and characterize the capacitance change as a function of the density of deposited material. The results were promissing but require further refinement for a strong correlation. All the particle beams were produced at the cluster source operating at the GFNMN group at the department of applied physics at IFGW Unicamp / Mestrado / Física / Mestre em Física / 2011/15018-7 / FAPESP

Title: Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films Author: Daniil Nikitin Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics/Charles University Abstract: The PhD thesis aims at the investigation of nanostructures based on plasma polymers. The main attention is paid to the combination of a gas aggregation cluster source with plasma-assisted vapor phase deposition for the fabrication of metal-polymer nanocomposites with bactericidal potential. Copper nanoparticles were incorporated into a biocompatible matrix of plasma polymerized poly(ethylene oxide) (ppPEO). The efficiency of such nanocomposite against multi-drug resistant bacteria was demonstrated. It was found that the segmental dynamics of the plasma polymer significantly changed in the presence of nanoparticles as revealed by the measurements of the dynamic glass transition temperature. The nanoscale confinement crucially influences the non-fouling properties of poly(ethylene oxide). A separate chapter is dedicated to the examination of the nanoparticle formation, growth and transport inside the source. Copper and silver nanoparticles were detected in situ in the gas phase...

Title: Structuring of plasma polymers: new methods for fabrication of nano-architectured thin films Author: Daniil Nikitin Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Doc. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics/Charles University Abstract: The PhD thesis aims at the investigation of nanostructures based on plasma polymers. The main attention is paid to the combination of a gas aggregation cluster source with plasma-assisted vapor phase deposition for the fabrication of metal-polymer nanocomposites with bactericidal potential. Copper nanoparticles were incorporated into a biocompatible matrix of plasma polymerized poly(ethylene oxide) (ppPEO). The efficiency of such nanocomposite against multi-drug resistant bacteria was demonstrated. It was found that the segmental dynamics of the plasma polymer significantly changed in the presence of nanoparticles as revealed by the measurements of the dynamic glass transition temperature. The nanoscale confinement crucially influences the non-fouling properties of poly(ethylene oxide). A separate chapter is dedicated to the examination of the nanoparticle formation, growth and transport inside the source. Copper and silver nanoparticles were detected in situ in the gas phase...

Smooth fluorocarbon plasma polymer films have been for a long time considered for fabrication of hydrophobic and slippery coatings. Interest in fluorocarbon materials was also supported by their excellent self-lubricant, dielectric properties and chemical inertness. This thesis is focused on development of new methods for fabrication of fluorocarbon plasma polymes, which could combine the chemical composition and the physical structure necessary for reaching superhydrophobic character of coatings. Poly(tetrafluoroethylene) was the subject material. RF magnetron sputtering using gas aggregation cluster source was the method adapted to fabricate fluorocarbon nanostructured films with chemical composition close to conventional bulk PTFE, but with high degree of cross- linking and branched structure. A model of growth of such plasma polymer nanostructures was discussed.

Title: Multicomponent plasma polymers with spatially controlled properties Author: MSc. Pavel Pleskunov Department / Institute: Department of Macromolecular Physics/Charles University Supervisor of the doctoral thesis: Prof. Ing. Andrey Shukurov, PhD, Department of Macromolecular Physics / Charles University Abstract: Mixing of two (or more) polymers often leads to phase separation and to the formation of nanoscale architecture, which can be highly attractive in various applications including controllable drug delivery, fabrication of separation and solid electrolyte membranes, gas storage, etc. Different wet-chemistry techniques already exist to produce nanophase-separated polymers; however, capturing the resultant polymeric structure in a predictable manner remains a challenging task. In this thesis, a low-temperature plasma-based strategy is investigated for the production of multicomponent thin films of plasma polymers with spatially discriminated nanoscale domains. Gas aggregation cluster source is used for the fabrication of nanoparticles of plasma polymerized acrylic acid, whereas Plasma-Assisted Vapor Phase Deposition is used for the deposition of thin films of poly(ethylene oxide) plasma polymer. Embedding of nanoparticles into matrices of thermodynamically incompatible plasma polymer as well as...