Plasma polymerisation (PP) is an emerging processing technology with immense potential for future industrial applications, which is increasingly being used for the fabrication of functional coatings on polymeric substrates. In this technique, the solid polymeric film is directly deposited onto the substrate surface to create a new surface of very interesting and unique properties. PP utilizes gas phase chemistries in low-pressure environment to produce well-defined high quality films in controllable and tunable fashion. A major advantage of this process is that it is an environmental safety technique and strategically superior compared to other thin film deposition techniques such as spin coating and spray coating. In general, the quality of the plasma polymer film can be controlled, precisely and reproducible. However, mechanism of the coating under plasma polymerisation is complex and has not yet been completely understood. / The ethylene propylene diene terpolymers (EPDMs) are increasingly being used in numerous technological applications, such as automotive sealing sections (~25kg of elastomer is used in an average car) due to their elasticity. ozone resistance, low weight, ease of fabrication in desired shape/form; favorable mechanical properties and low cost. However, the deficiency of EPDM in the surface specific secondary engineering characteristics that may play a critical role in many applications is encountered. The performance of this elastomeric materials may be further enhanced by deposition of organic surface coatings, which can satisfy one or more surface specific functions including, hydrophobicity, low friction, high abrasion resistance, decorative and protective coatings against harsh terrestrial and/or space environments, etc. / In this PhD thesis the objectives of the research were focused on: (i) creation of low friction and high abrasion resistance ultra thin functional PP coating onto EPDM substrate surface using fluorocarbons and organosilicones as precursors, (ii) investigation of the structure-property-processing relationship of the deposited film in detail, (iii) development of new plasma thin film characterisation and performance evaluation techniques. / Thesis (PhDAppliedScience)--University of South Australia, 2004.

Plasma polymerisation (PP) is an emerging processing technology with immense potential for future industrial applications, which is increasingly being used for the fabrication of functional coatings on polymeric substrates. In this technique, the solid polymeric film is directly deposited onto the substrate surface to create a new surface of very interesting and unique properties. PP utilizes gas phase chemistries in low pressure environment to produce well-defined high quality films in controllable and tunable fashion. A major advantage of this process is that it is an environmental safety technique and strategically superior compared to other thin film deposition techniques such as spin coating and spray coating. In eneral, the quality of the plasma polymer film can be controlled, precisely and reproducible. However, mechanism of the coating under plasma polymerisation is complex and has not yet been completely understood. / PhDAppliedScience

Thesis (Ph.D.)--Australian National University, 2004. / Errata slip inserted.

Thesis (Ph.D.) - University of St Andrews, March 2007.

Thesis (M.S.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaves 106-108).

Thesis (M.S.)--University of Michigan, 1988.

Thesis (Ph. D.)-- University of Washington, 2005. / Vita. Includes bibliographical references (leaves 115-118).

Thesis--University of California. / Includes bibliography.

Orientador: Elidiane Cipriano Rangel / Banca: Antonio Riul Junior / Banca: Maria Lucia Pereira Antunes Silva / Resumo: Neste trabalho foi investigada a possibilidade de se criar padrões regularmente distribuídos sobre a superfície da poliamida (PA), utilizando o processo de deposição de filmes em plasmas de baixa pressão. Para tal, um único procedimento foi empregado utilizando-se uma malha metálica comercial (60 μm) como máscara para delinear pilares na superfície da poliamida. Os plasmas de deposição foram gerados a partir de atmosferas contendo 70% de hexametildisiloxano (HMDSO) e 30% de oxigênio a uma pressão total de 23 Pa, já incluído o valor de 3 Pa referente à pressão de fundo. O plasma foi ativado pela aplicação do sinal de radiofrequência (13,56 MHz, 150 W) no suporte de amostras enquanto o eletrodo superior permaneceu aterrado. O tempo de deposição, t, foi alterado de 15 a 90 min. Na etapa inicial do trabalho o filme foi uniformemente depositado sobre o polímero sem a utilização de máscara. Uma segunda etapa de experimentos foi realizada, utilizando-se condições idênticas às anteriores, mas com o auxílio da trama metálica sobre as amostras para guiar a deposição do filme somente nos poros da máscara. Filmes organosilicones, compostos por estruturas granulares e com espessuras dependentes de t, foram uniformemente depositados sobre a PA quando a máscara não foi utilizada. A deposição do filme independentemente da condição de t, aumenta a rugosidade superficial e transforma a amostra inicialmente hidrofílica em hidrofóbica. Muito embora t afete de forma suave a composição química, es... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this work investigated the possibility of creating patterns regularly distributed on the surface of the polyamide (PA), using the process of film deposition in low pressure plasmas. For such, a single procedure was employed using a commercial metallic mesh (60 um) as a mask to delineate pillars on the polyamine surface. The deposition plasmas were generated from atmospheres containing 70% of hexamethyldisiloxane (HMDSO) and 30% of oxygen at a total pressure of 23 Pa, already included the amount of 3 Pa related to the background pressure. The plasma was activated applying a radiofrequency signal (13.56 MHz, 150W) to the sample holder while grounding the topmost electrode. Deposition time t, was changed from 15 to 90 min. In the initial stage of the work the film was evenly deposited on the polymer without the usage of mask. A second step of experiments was performed, usign the same conditions as earlier, but with the aid of the metallic frame on the samples to guide the film deposition only in the pores of the mask. Organosiliciones films consisting of granular structures and thickness dependent of t were evenly deposited on the PA when the mask was not used. The film deposition, independently of condition of t, increases the surface roughness and transforms the sample initially hydrophilic to hydrophobic. Although t affects smoothly the chemical composition, molecular structure and wettability of the film, its effect on the layer thickness is substantial. Patterns in the form of pillars were regularly defined on the surface of PA with the organosilicon film deposition and the usage of the mask. The height of the pillars grows with t reaching up to 1 micrometers. For higher values of t, the mask did not acte effectively as shadow in the wire region. It was observed that the surface wettability was stage with the aging time and it was not affected by the patterns / Mestre

Orientador: Aruy Marotta / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-03T02:08:00Z (GMT). No. of bitstreams: 1 Bublievsky_DmitryAlexandrovich_M.pdf: 1177094 bytes, checksum: c681f9fa549216acb2481c1084c3e875 (MD5) Previous issue date: 2003 / Resumo: Nesta tese foi introduzido um novo tipo de técnica de diagnóstico da mancha de arcos elétricos, chamado térmico-espectroscópico. A técnica foi aplicada ao estudo da velocidade de rotação da mancha do arco e da densidade de corrente na mancha. Ambas estão relacionadas com os fenômenos que ocorrem na erosão de eletrodos frios. As medidas foram realizadas em um catodo de cobre não refrigerado, operando em ar, usando uma instalação coaxial magnética. As experiências mostraram que há dois regimes de erosão: micro e macroerosão. Observamos que para o regime de microerosão, a velocidade é sempre maior, e a dispersão da velocidade sempre menor que na macroerosão. Ambos os fatos confirmam a existência de uma força de arraste de superfície ao movimento do arco. Podemos explicar que a fonte dessa força é proveniente dos jatos catódicos no regime de macroerosão, fazendo com que a mancha tenha um movimento descontínuo. As dificuldades das técnicas tradicionais de medida da densidade de corrente na mancha foram superadas, introduzindo-se o conceito de densidade de corrente efetiva na mancha, pela qual mede-se o início da fusão na mancha e não o diâmetro da mancha. O método, baseado no registro espectroscópico temporal da intensidade da linha de emissão do vapor de cobre, juntamente com o registro da evolução da temperatura da superfície do eletrodo, permitiu um grande aumento na sensibilidade de detecção do ponto de transição do regime de micro para macroerosão. A densidade de corrente da mancha, medida como uma função do campo magnético, apresenta um grande crescimento para baixos valores do campo magnético. O estudo experimental realizado nesta tese permite uma melhor compreensão dos fenômenos que ocorrem em manchas de arcos elétricos de eletrodos frios, contribuindo, assim, para uma maior utilização das tochas de plasma / Abstract: In this thesis, we introduced a new type of arc spot diagnostic technique, called thermo-spectroscopic. Attention was concentrated on the study of arc spot rotation velocity and arc spot current density as a function of magnetic field. Both are related to cold electrode erosion phenomena. Measurements were carried out in an uncooled copper cathode in air, using a magnetically driven arc coaxial setup. Experiments have shown that there are two erosion regimes: a micro and a macroerosion one. We observed that for the microerosion regime, velocity was always higher and velocity dispersion lower than for the macroerosion one. Both facts confirm the existence of a surface drag force to the movement of the arc. We could explain that the source of this force is provided by cathode jets in the macroerosion regime, making the spot to move with frequent stops. We overcame the difficulties in traditional techniques in measuring spot current density by introducing the concept of effective arc spot current density, by which we measure the spot fusion onset and not the arc spot diameter. The method, based on the temporal spectroscopic registration of copper vapor atomic line emission intensity, together with the registration of the electrode surface temperature evolution, provided a significative increase in the sensibility of detection of the transition point from micro to macroerosion. The arc spot current density, measured as a function of magnetic field shows a strong increase for low magnetic field values. Experimental study, carried out in this thesis, allows a better understanding of the phenomenon taking place in cold electrode arc spot, thus contributing for a wider utilization of plasma torches / Mestrado / Física / Mestre em Física