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Dissertations / Theses on the topic 'Plasma polymerization'
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1
Ryan, Martin Edward. "Mechanistic studies of plasma polymerization." Thesis, Durham University, 1995. http://etheses.dur.ac.uk/5455/.
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Plasma polymerization is a solventless method for depositing polymeric layers onto any substrate at room temperature. This technique comprises excitation, fragmentation, and polymerization of precursor molecules by an electrical discharge. Although widely used, the fundamental molecular processes associated with plasma polymerization are not fully understood. Basic plasma / polymer interactions were studied by investigating the surface treatment of polytetrafluoroethylene (PTFE) using inert and reactive gas discharges. Depending upon the feed gas employed, chemical, UV, or ion beam modification of the PTFE surface were found to be important. Argon glow discharge treatment was found to result in similar physicochemical phenomena at the PTFE surface to that observed during argon ion beam studies, thereby supporting the relative importance of ion bombardment during noble gas plasma modification. In high power discharges it has been shown that extensive ion bombardment of PTFE can lead to the simultaneous sputtering and plasma polymerization of ejected species onto an adjacent substrate. The chemical nature of the resultant fluorocarbon deposits for various gases was found to correlate to the earlier surface treatment studies. Another way of carrying out plasma polymerization is to use pulsed plasmas; these offer the advantage of greater retention of monomer structure within the plasma polymer matrix. In the case of maleic anhydride less fragmentation of the precursor, reduced beam damage of the polymer, and radically initiated polymerization was observed by increasing the off-period of the pulse. Similarly the structural characteristics of 2- iodothiophene plasma polymers were found to be influenced by the electrical discharge power and pulsing parameters leading to a gradual destruction of the aromatic ring structure.
2
FIELDING, JENNIFER CHASE. "FLUORINATION OF SILICONE RUBBER BY PLASMA POLYMERIZATION." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1085442499.
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Gilliam, Mary A. "A plasma polymerization investigation and low temperature cascade arc plasma for polymeric surface modification." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4355.
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Thesis (Ph.D.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 25, 2007) Vita. Includes bibliographical references.
4
Tarducci, Cinzia. "Functionalization of solid surfaces by pulsed plasma polymerization." Thesis, Durham University, 2002. http://etheses.dur.ac.uk/4157/.
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Pulsed plasma polymerization provides a direct method for the functionalization of solid surfaces. Compared to low power continuous wave plasma conditions, it provokes very little monomer fragmentation and leads to high levels of structural retention. The monomers investigated in this thesis contained a polymerizable double bond and either a perfluoro, epoxide, cyano, hydroxyl or furan functionality. Under pulsed conditions activation of the double bond occurs during the time on period and conventional intermolecular propagation reactions occur during the time off. In the case of dienes, cyclic structures are formed, via intramolecular propagation. The plasma polymers were investigated using X-ray photoelectron, infrared, ultraviolet/visible and secondary ion mass spectroscopies, nuclear magnetic resonance, contact angle and gel permeation chromatography. Epoxide and hydroxyl functionalized solid surfaces could be further functionalized via conventional chemistry reactions. Furan functionalized solid surfaces were capable of undergoing Diels-Alder reactions. The cyano functionalized layers were found to readily complex silver ions from solution. Epoxide and cyano functionalized surfaces exhibited adhesive behavior.
5
JOHNSON, ERIC MICHAEL. "PLASMA POLYMERIZATION FOR THE FABRICATION OF OPTICAL STACKS." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1004706209.
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Huang, Chun. "An optical emission study on DC plasma polymerization /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418031.
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Kostyleva, Kseniia. "Příprava vrstev metodou plazmové polymerace a jejich charakterizace." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2021. http://www.nusl.cz/ntk/nusl-449395.
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The diploma work deals with the preparation of biocompatible hydrophilic layers from a propane-butane mixture by plasma polymerization. Subsequent characterization of the layers was performed using both biological (antibacterial tests and biocompatibility test) and physico-chemical diagnostics (SEM, OES and surface energy determination). The theoretical part presents the basic principle of dielectric barrier discharge, its use and various types, including surface dielectric barrier discharge (SDBD), which was used during deposition. Next, cell cultures, cell morphology and clarification of the term biocompatibility were described. At the end of the theoretical part, all used during the experimental part of the diagnostics were also described. In the experimental part, the procedure of deposition of hydrophilic layers and the overall apparatus, which was used during deposition, were presented. Prior to the characterization of the samples, the discharge was diagnosed using optical emission spectroscopy. Furthermore, the level of hydrophilicity of the layers and their elemental composition on the surface was determined. Biological tests for biocompatibility and antibacterial properties provided information on the viability of the cells on the layers and their antibacterial effects.
8
Unver, Alper. "Plasma Induced Solid State Polymerization Of N-isopropylacrylamide (nipam)." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609242/index.pdf.
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Poly(N-isopropylacrylamide) (PNIPAM) is a smart polymer exhibiting an inverse temperature-solubility relationship with a sharp transition at 32°C in its aqueous solution. Due to its reversible thermo-responsive phase transition behavior at around body temperature, PNIPAM promise a potential for a variety of novel applications especially in biotechnology and medicine. PNIPAM can be produced by conventional polymerization methods, as well as by use of ionizing radiation, primarily by gamma which leads mainly to a residual-free crosslinked polymer. In this study, RF plasma (glow discharge) technique is used as a novel synthesis method in solid state leading to higher proportions of linear polymer. Since plasma method is an additive-/initiator-free process, a residual-free polymer is expected. To obtain a better understanding of the plasma induced solid state polymerization mechanism of NIPAM, X-ray data are used. It is found that crystalline structures of Acrylamide (AAm) and NIPAM are isomorphous. Plasma and post plasma aging effects on crystalline structure of NIPAM are followed. From the Electron Paramagnetic Resonance (EPR) investigations it is observed that post plasma polymerization of NIPAM in solid state proceed by radicalic mechanism. After determination of temperature range in which the radical formed by plasma treatment of NIPAM is highly stable, decay kinetics of the propagating radical in solid state after plasma treatment has been studied in detail.
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Zhang, Ning. "SURFACE MODIFICATION OF MICRON-SIZE POWDERS BY PLASMA POLYMERIZATION." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin971280515.
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Slapelis, Linda. "Plasma modification of poly(ester sulfonic) acid anionomeric membranes /." Online version of thesis, 1994. http://hdl.handle.net/1850/11445.
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Jordan, Alexander Thomas. "Liquid phase plasma technology for inkjet separation." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47543.
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Currently most deinking technologies are dependent upon flotation and dissolved air flotation
(DAF) technology in order to separate inkjet ink from fiber and water. Much of this
technology is based on ink that is extremely hydrophobic. This made flotation and DAF
very easy to use because the ink in the water would very easily move with the air in flotation
and be brought to the surface, after which the ink can be skimmed and the pulp can
be used.
Now that small scale printing has become the norm, there has been a move to high
quality, small scale printing. This involves the use of a hydrophilic ink. Hydrophilic ink
cannot be easily separated from water and fiber the same way the hydrophobic ink can be.
With low concentrations of hydrophilic ink in the process water stream, it can be absorbed
into the process but as the hydrophilic ink concentration rises alternative methods will be
needed in order to separate inkjet ink from water.
One solution is to find a method to effectively increase ink particle size. This will
enable the ink particles to be filtered or to have an increase ecacy of removal during
flotation. In this thesis, one solution is discussed about how electric field and electric
plasma technologies can be used to increase particle size and help purify process water in
recycle mills.
This plasma treatment can very effectively bring ink particles together so that they may
be separated by another method. There are two methods by which this may take place. One
is polymerization and the other is electro-coagulation. These processes can work side by
side to bring ink particles together.
This plasma treatment process creates free radicals by stripping off hydrogen atoms
from surrounding organic matter. These free radicals then react with the high alkene bond
content within the ink to create a very large covalently bonded molecule. This is the new
mechanism that is being investigated in this thesis. The other action that is taking place is electro-coagulation.
Plasma treated ink can be filtered out using a cellulose acetate or cellulose nitrate membrane
or they can be filtered using paper or fiber glass filters as well. The extent at which
these can be filtered out is dependent on the size of the pores of the filter. In this study, it
was shown that the plasma treatment was able to clean water with a fairly small amount
of energy. It was also found that treatment time and concentration had very little eect on
the outcome of the treatment ecacy. One factor that did have an effect was the pH. At
very high pH values the process became noticeably less eective. The high pH essentially
eliminated the electro-coagulation aspect of the treatment process and also hurt the polymerization
aspect as well because of lower amount of hydrogen atoms available for the
plasma to create free radicals.
A model of the process was used to try to give the reader an idea of the ecacy that the
process would have in an industrial scale process. The model assumes that two types of ink
particles exist. One is ink that has a radical and another in which the ink does not have a
radical. The model also assumes that if ink is at all polymerized, ink is filtered out with the
0.8 micron filter. The model assumes three reactions; initialization, propagation and partial
termination. The partial termination is a result from the general chemical structure of ink.
Ink has many double bonds in its general structure which makes termination very unlikely
to occur, so the model assumes that on average when two radials interact that only one is
eliminated. This model is only supposed to give the reader an idea of the ecacy of the
process. The numbers provided in the model will change very significantly in a different
system.
The evidence behind polymerization aspect of the process comes from two main sources.
One is the small molecule analysis from methanol after being exposed to the plasma and the
other from the plasma being exposed to allyl alcohol. The small molecule analysis shows
that the process generates free radicals on organic molecules. Methanol was exposed to
the plasma and then the resulting GC/MS analysis showed that 1,2-ethanediol was present, this showed that the electric discharge process was able to create free radicals on organic
molecules in the liquid phase.
Using a similar process the plasma discharge process was exposed to a mixture of allyl
alcohol, water and propanol and water in two separate experiments. The difference between
these two molecules is an alkene bond that is between the carbon two and carbon three
atoms. The particle size of both samples was then analyzed and it was shown that the
solution with allyl alcohol had an average particle size about an order of magnitude larger
than the solution with propanol in it.
Because of all the evidence discussed here and in the rest of the thesis we believe that
the plasma treatment of ink has both polymerization and electro-coagulation aspect. This
process could also be a potential solution to the water soluble ink problem that will soon
face the recycling industry.
12
Tamirisa, Prabhakar A. "Plasma polymerized hydrogel thin films for applications in sensors and actuators." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2006. http://hdl.handle.net/1853/19827.
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Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2007.Committee Chair: Hess, Dennis W.; Committee Member: Henderson, Cliff L.; Committee Member: Hunt, William D.; Committee Member: Meredith, J. Carson; Committee Member: Prausnitz, Mark R.
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Till, Clare. "An investigation of plasma polymerization and copolymerization using fluoroaromatic compounds." Thesis, Durham University, 1986. http://etheses.dur.ac.uk/6834/.
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The work detailed in this thesis concerns polymers synthesised by R.F. inductively coupled plasmas excited in fluorine containing monomer vapours. The structure and bonding in a series of polymers prepared from per-fluoroaromatic monomers by plasma polymerization was investigated by ESCA. The composition and structural features of these films were compared and contrasted with each other and with plasma polymers derived from the same parent compounds with lower degrees of fluorination. Critical emission spectra, ~260-600nm, from these plasmas were recorded and a correlation made between certain species fluorescing in the gas phase and functional groups within the polymer. An association hcis also been made between the peaks at ~280 and ~510nm in the optical emission spectrum. Difluorocarbene is responsible for the peak at ~280nm but the peak at 510nm has an unknown origin. The effect of copolymerizing a fluoroaronatic compound with a second component on polymer composition has been examined, where the comonomer has ranged from an inert gas to an organic hydrocarbon analogue. Copolymerizaticn resulted in a stabilisation of the rearrangement mechanisms normally associated with the plasma polymerization of a perfluoroaromatic compound; CF=CF(_n) and CF(_2) groups were greatly reduced in intensity in the ccpolymer. The binding energy of the CF-CF(_n) peak indicated that the component peak was, in fact, due to CF-CF(_aromatic) i.e. copolymerization had also resulted in a greater retention of the aromatic nature of the parent fluorocotpound. Polymers were also prepared by irradiating the monomer vapour with wavelengths >130nm. Perfluorobenzene could not be polymerized with UV irradiation of wavelengths greater than 200nm, but could however be polymerized with wavelengths below 200nm. This produced a polymer whose composition, as determined by ESCA, was very similar to the composition of plasma polymers derived from the same monomer indicating that the mechanisms involved in both polymerizations are similar. Vibrationally excited ground state perfluorobenzene is thought to be involved in the reaction pathway.
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MANIAN, HRISHIKESH. "MECHANICAL AND PROTECTIVE PROPERTIES OF RF DEPOSITED PLASMA POLYMERS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1108996115.
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Anderson, Kyle D. "Functional and complex topological applications of plasma polymerized ultrathin films." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/48969.
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This study is focused on the fabrication of plasma polymerized ultrathin films and the elucidation of their unique properties with an emphasis on the solvent-less, dry polymerization process to introduce post-deposition functionality, robustness, and shape preservation. Two major classes of materials are the subject of this study: biological monomers, specifically the amino acids tyrosine and histidine and synthetic organic and inorganic monomers including acrylonitrile, 2-hydroxyethyl methacrylate, N-isopropylacrylamide, titanium isopropoxide and ferrocene. The unique chemical and physical properties of highly cross-linked ultrathin plasma polymerized amino acid and synthetic polymer films are demonstrated along with their functional response and robustness on both planar and complex surface structures. The work emphasizes the facile ability of plasma polymerization to create unique, tailored ultrathin coatings. Chemical functionality retention (OH, NH₂) of the tyrosine and histidine amino acids is demonstrated by the subsequent mineralization of gold or titania nanoparticles on the plasma polymerized ultrathin films using a wet chemical approach. Inorganic nanoparticle mineralization is further investigated as a method to modify the optical properties of composite nanocoatings. Plasma co-polymerization of tyrosine and synthetic monomers is used to create nanocomposite coatings with unique surface functionalities, responsive behavior, optical characteristics and a high level of integration between monomers. The fabrication of novel plasma polymerized Janus microspheres, micropatterned substrates and free-standing films also demonstrate numerous plasma polymerized materials which exhibit unique structural properties. Overall, facile plasma polymerization of novel, functional ultrathin films and complex topological coatings having potential biocompatible and optical applications is established.
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Weikart, Christopher M. "Plasma-induced fluid holding capability of polymeric materials /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9974700.
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Keen, Imelda dePaz. "The plasma-induced copolymerisation of polystyrene onto polypropylene-polyethylene copolymer substrates." Thesis, Queensland University of Technology, 2002.
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Chen, Xiao Hua. "Patterning etch masks via the "Grafting-from polymerization." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/30768.
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Francesch, de Castro Laia. "Surface modification of Polymers by plasma polymerization techniques for tissue engineering." Doctoral thesis, Universitat Ramon Llull, 2008. http://hdl.handle.net/10803/9290.
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El treball que es presenta en aquesta tesi pretén contribuir al camp de la ciència de superfícies biològiques, amb el desenvolupament de superfícies adaptades amb cadenes lateral reactives per tal de unir covalentment biomolècul·les d'interès a la superfície.La polimerització assistida per plasma del recobriments actius és un mètode atractiu per tal d'obtenir cadenes laterals reactives, mitjançant pel·lícules nanomètriques amb densitats de grups funcionals adaptats. Sota control de les condicions experimentals, l'estructura del dipòsit polimèric es pot control i les estructures químiques obtingudes poden variar des de xarxes polimèriques altament funcionalitzades amb baixa reticulació fins a xarxes altament reticulades amb baix contingut funcional.
La recerca descrita en aquesta tesi tracta de la modificació de superfície de diversos substrats per polimerització de plasma. La part essencial del treball es dirigeix cap al funcionalització amb grups èster de pentafluorofenil a la superfície, durant la polimerització per grafting i polimerització de plasma pulsat de pentafluofenil metacrilat. Aquesta classe de grup làbil és de gran interès per a la seva fàcil reactivitat amb molècules amb mines terminals, com pèptids. Altres monòmers comercials també s'han emprat al començament de l'estudi, com a primera aproximació a les tècniques de plasma. La caracterització d'aquestes superfícies s'ha fet a través de tècniques analítiques com FTIR, XPS, AFM o ToF - SIMS entre d'altres.
A més, s'ha dut a terme un estudi per fer a mida el polímer de PFM per a millorar la retenció de la seva estructura, i així com un estudi profund de la seva reactivitat davant de molècules amb amines terminals diferents d'interès, afegint SPR o l'aplicació de sensors microcantiliver a les tècniques de caracterització per aconseguir una millor comprensió de la química i cinètica de la reacció.
Sobre el propòsit d'aconseguir superfícies funcionalitzades útils, s'ha realitzat un patterning de les superfícies amb l'ús de màscares per a capa selectiva de les mostres per controlar les àrees modificades. Això s'ha fet per a l'aplicació d'aquesta pel·lícula a dispositius reals, així com a prova de la seva biocompatibilitat per cultiu cel·lular i per assaigs in vivo.
El trabajo que se presenta en esta tesis pretende contribuir al campo de la ciencia de superficies biológicas, con el desarrollo de superficies adaptadas con cadenas lateral reactivas con el fin de unir covalentemente biomoléculas de interés a la superficie.
La polimerización asistida por plasma de recubrimientos activos es un método atractivo con el fin de obtener cadenas laterales reactivas, mediante películas nanométricas con densidades de grupos funcionales adaptados. Bajo control de las condiciones experimentales, la estructura del depósito polimérico se puede control y las estructuras químicas obtenidas pueden variar desde redes poliméricas altamente funcionalitzadas con baja reticulación hasta redes altamente reticuladas con bajo contenido funcional.
La investigación descrita en esta tesis trata de la modificación de superficie de diversos sustratos por polimerización de plasma. La parte esencial del trabajo se dirige hacia el funcionalización con grupos éster de pentafluorofenilo en la superficie, durante la polimerización por grafting y polimerización de plasma pulsado de pentafluofenilmetacrilato. Esta clase de grupo lábil es de gran interés para su fácil reactividad con moléculas con minas terminales, como péptidos. Otros monómeros comerciales también se han servido al principio del estudio, como primera aproximación a las técnicas de plasma. La caracterización de estas superficies se ha hecho a través de técnicas analíticas como FTIR, XPS, AFM o ToF - SIMS entre otros.
Además, se ha llevado a cabo un estudio para hacer a medida el polímero de PFM para mejorar la retención de su estructura, y así como un estudio profundo de su reactividad delante de moléculas con aminas terminales diferentes de interés, añadiendo SPR o la aplicación de sensores microcantiliver a las técnicas de caracterización para conseguir una mejor comprensión de la química y cinética de la reacción.
Sobre el propósito de conseguir superficies funcionalizadas útiles, se ha realizado un patterning de las superficies con el uso de máscaras para capa selectiva de las muestras para controlar las áreas modificadas. Eso se ha hecho para la aplicación de esta película en dispositivos reales, así como a prueba de su biocompatibillidad por cultivo celular y para ensayos in vivo.
The work presented in this thesis has the main aim to contribute in the field of biological surface science, by developing tailored surfaces with reactive side chains in order to attach desired biomolecules to the surface by a covalent link.
Plasma polymerization of surface active coatings is an attractive method to obtain reactive side chains, by making nanometer thick films of tailored functional group densities. By controlling the experimental conditions, the structure of the polymer deposit can be largely controlled and the chemical structures obtained can range from highly functional polymer networks of low cross link density to polymer networks of low functional group but high cross link densities.
The research described in this thesis deals with the surface modification of various substrates by plasma polymerization. The major part of the work is directed towards the funtionalization with pentafluorophenyl ester groups on the surface, through the grafting polymerization and pulsed plasma polymerization of pentafluophenyl methacrylate. This kind of labile group is of high interest for its easy reactivity to amino terminated molecules, such as peptides. Other commercial monomers were also used at the beginning of the study, as a first approach to the plasma techniques. The characterization of these surfaces is done through several analytical techniques as FTIR, XPS, AFM or ToF-SIMS among others.
Furthermore, a study for tailoring the PFM polymer for better structure retention and deep study of its reactivity in front of different amino terminated molecules of interest was performed, adding SPR or the implementation of microcantilever sensors to the characterization techniques to achieve a better understanding of the chemistry and kinetic of the reaction, in order to achieve the best peptide binding for reliable well characterized bioactive interface..
On the aim of achieving useful functionalized surfaces, a patterning of the surfaces with the use of masks for selective coating of the samples has been performed to control the modified areas. This has been done for application of this film to real devices, as well as to test of its biocompatibility by cell culture and in vivo assays.
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Young, Kevin. "Equivalent circuit modeling of TMS plasma polymer coating system on cold-rolled steel." Diss., Columbia, Mo. : University of Missouri-Columbia, 2004. http://hdl.handle.net/10355/4104.
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Thesis (M.S.) University of Missouri-Columbia, 2004.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 30, 2006). Vita. Includes bibliographical references.
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Fernandes, Fábio Luis Figueiredo [UNESP]. "Perfil de índices de refração do cristalino humano: simulação computacional." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/91807.
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Este trabalho trata da simulação da ótica do olho humano, em especial a determinação do perfil de índices de refração do cristalino. Mostramos que a hipótese de índice de refração constante, para os meios óticos, não é adequada quando o objetivo é minimizar aberrações e se fazer um estudo da imagem formada na retina. Desenvolvemos um código computacional que utiliza a técnica do Traçado de Raio (ray tracing) acoplada a um processo de busca e otimização (recozimento simulado), visando determinar o perfil de variação dos índices de refração do cristalino, com a condição de minimização das aberrações. A parametrização do modelo foi baseada em resultados da Literatura e utilizamos faces asféricas (parabólicas). Para validar nosso modelo, comparamos nossos resultados com outros modelos existentes, e verificamos a qualidade da imagem formada na retina
This work deals with the human eye optics simulation, focusing in the lens refraction index profile. We show that the hypothesis of constant refraction index, for the lens, is not adequate when the objective is minimize aberrations and to study the image formed in the retina. We developed a computational code that uses the ray tracing technique coupled to a search and optimization algorithm (simulated annealing), seeking to determine the profile of the refraction index for the crystalline lens that minimize the aberrations. The model's parametrization was based on Literature results and we implemented aspherical faces for the lenses. In order to validate our results, we compare with those in the Literature, and verify the image quality formed on the retina
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Tomečková, Klára. "Depozice a charakterizace polymerních vrstev připravených na bázi 2-methyl-2-oxazolinu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-414133.
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Polyoxazolines are class of polymers which are suitable for medical applications because they have many interesting properties. These polymers are characterized by antibacterial properties so they can stop bacterial colonization of medical devices and significantly reduce the risk of infection. Furthermore, polyoxazolines are interesting for good biocompatibility. Basic topic of this diploma work is preparation of oxazoline-based thin films by plasma polymerization. Thin films were prepared by plasma polymerization from 2-methyl-2-oxazoline vapors in a nitrogen atmosphere in a dielectric barrier discharge. During the deposition was increased the substrate temperature. Polyoxazoline films were analyzed by several diagnostic methods. Physical and chemical properties of thin films were studied by SEM, AFM, FTIR by measuring contact angles and nanoindentation method. The films were found to be homogeneous, hydrophilic and have a higher nitrogen content. Furthermore, films showed viscoelastic properties. Polyoxazoline films were subjected to antibacterial and biocompatibility tests and the result showed, that films have antibacterial properties and support of viability cells viability.
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Lu, Kan P. "Surface modulation of fluoropolymers for the improvement of adhesion : O₂-CF₄-Ar radio frequency plasma modification of poly (tetrafluoroethylene) /." Online version of thesis, 1994. http://hdl.handle.net/1850/11696.
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Kim, Hong-Youl. "PMMA bone cement reinforced by plasma treated particles /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841158.
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Yu, Zhou. "Surface Polymerization, Interface Structure, and Low Temperature Consolidation of Nano Ceramic Particles." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin971379308.
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Huang, Chun. "An experimental investigation of low temperature plasma sterilization, treatment, and polymerization processes." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4434.
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Thesis (Ph.D.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 26, 2007). Vita. Includes bibliographical references.
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Nagai, M., M. Hori, and T. Goto. "Decomposition and polymerization of perfluorinated compounds in microwave-excited atmospheric pressure plasma." American Institute of Physics, 2005. http://hdl.handle.net/2237/7053.
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Lotz, Alexander [Verfasser]. "Designing an antimicrobial and cell-adhesive multilayer via plasma polymerization / Alexander Lotz." Mainz : Universitätsbibliothek Mainz, 2012. http://d-nb.info/1022299956/34.
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Lewis, Gregory Todd. "Surface nano-structuring of materials by atmospheric pressure plasma-induced graft polymerization." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1695050961&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Gao, Yong. "Surface modification of nanoparticles and nanotubes by plasma polymerization and properties characterization." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1091480190.
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Qin, Cao. "Synthesis of organic layer-coated metal nanoparticles in a dual-plasma process." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103280.
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A novel dual-plasma process for the synthesis of organic layer-coated metal nanoparticles is presented. Metal nanoparticles are synthesized by the low-pressure pulsed arc evaporation of a metal cathode surface, followed by the in-flight deposition of a thin organic layer by capacitively-coupled radio-frequency (CCRF) plasma polymerization from a gaseous hydrocarbon monomer. The system is simple to operate and can be designed for high throughput. The combination of the synthesis and surface treatment of metal nanoparticles in the whole system avoids newly produced metal nanoparticles from being contaminated by surrounding environment.A home-made self-oscillatory pulsed power supply has been designed and built for the arc evaporation of metal sources. The stability of the pulsed arc system and the cathode erosion rate are discussed. The inductor present in the discharge loop is shown to have a stabilizing effect on the train of pulsed arcs. It was shown that the erosion rate was strongly dependent on peak arc currents due to the increased emission of macroparticles with peak arc currents, and the yield of metal nanoparticles was found to be slightly influenced by the peak arc current.
The produced coated copper nanoparticles were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). It was revealed that the coated copper nanoparticles have a metal core of size ranging from a few to 50 nm, and that the thickness of the organic layer ranges from 3 to 10 nm. The smallest copper nanoparticles are crystalline, while the organic coating has a macromolecular structure and shows a hydrophobic behavior. The XPS results showed that the plasma polymer film is chemically adsorbed onto the surface of the copper nanoparticle.
The effects of operating conditions such as reactor pressure and inert gas flow rate on the average size of the produced bare copper nanoparticles were studied. It was demonstrated that the metal nanoparticle size tends to decrease with decreasing reactor pressure, while inert gas flow rate has little influence on the mean nanoparticle size.
The morphology of the plasma polymer coating was revealed to be strongly dependent on the RF plasma power, reactor pressure, and inert gas flow rate. Two kinds of organic films were produced: a smooth, uniform and dense polymer film and a liquid polymer film. Based on a series of experiments, a "characteristic map" for the in-flight plasma polymerization from the C2H 6 monomer generating an organic layer onto the Cu nanoparticles was developed. A simplified free-radical mechanism was proposed for the plasma polymerization from ethane.
Other metal sources such as iron and aluminum were used as cathodes in the arc evaporation reactor. Transmission electron microscopy confirmed the production of coated nanoparticles similar in morphology to the ones obtained with the copper cathode. Lastly, ethylene glycol vapor were introduced as an alternative monomer into the plasma polymerization region. A non-uniform coating was observed on the metal nanoparticle surface.
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Fernandes, Fábio Luis Figueiredo. "Perfil de índices de refração do cristalino humano: simulação computacional /." Guaratinguetá : [s.n.], 2004. http://hdl.handle.net/11449/91807.
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Orientador: Carlos Renato ZachariasBanca: Ernesto Vieira Neto
Banca: Alvaro Jose Damião
Resumo: Este trabalho trata da simulação da ótica do olho humano, em especial a determinação do perfil de índices de refração do cristalino. Mostramos que a hipótese de índice de refração constante, para os meios óticos, não é adequada quando o objetivo é minimizar aberrações e se fazer um estudo da imagem formada na retina. Desenvolvemos um código computacional que utiliza a técnica do Traçado de Raio (ray tracing) acoplada a um processo de busca e otimização (recozimento simulado), visando determinar o perfil de variação dos índices de refração do cristalino, com a condição de minimização das aberrações. A parametrização do modelo foi baseada em resultados da Literatura e utilizamos faces asféricas (parabólicas). Para validar nosso modelo, comparamos nossos resultados com outros modelos existentes, e verificamos a qualidade da imagem formada na retina
Abstract: This work deals with the human eye optics simulation, focusing in the lens refraction index profile. We show that the hypothesis of constant refraction index, for the lens, is not adequate when the objective is minimize aberrations and to study the image formed in the retina. We developed a computational code that uses the ray tracing technique coupled to a search and optimization algorithm (simulated annealing), seeking to determine the profile of the refraction index for the crystalline lens that minimize the aberrations. The model's parametrization was based on Literature results and we implemented aspherical faces for the lenses. In order to validate our results, we compare with those in the Literature, and verify the image quality formed on the retina
Mestre
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Santos, Miguel. "Synthesis of bio-functional nanomaterials in reactive plasma discharges." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17921.
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Plasma processing technologies have been extensively used as surface modification platforms in many biomedical applications. Particularly, plasma polymerization (PP) is a versatile deposition technology which has the potential to deliver biocompatible interfaces for a myriad of medical devices. To successfully translate new materials for specific clinical applications, the plasma process needs to be scalable and incorporate appropriate control feedback strategies. However, the plasma medium in PP is exceptionally complex and identifying the main physical quantities that allow a suitable formulation and description of the interface growth mechanisms is challenging. The first part of the thesis reports the design and optimization of a single step ion assisted PP process to create plasma-activated coatings (PAC) that meet the extreme mechanical demands for cardiovascular implants and in particular stents. An ideal working window in the parameter space is identified, and found suitable for the synthesis of PAC interfaces that are mechanically robust, hemocompatibility and allow one step covalent protein immobilization without the need for chemical processes. This window is identified by combining plasma optical emission spectroscopy (OES) with a comprehensive macroscopic process description that isolates key coating growth mechanisms. During process scalability, OES diagnostics revealed the formation of plasma polymer nanoparticles (nanoP3), usually known as plasma dust, in parallel with the deposition of PAC coatings. The second part of the thesis reports the demonstration of carbonaceous plasma nanoparticles for nanomedicine applications. By controlling nanoparticle formation and collection, nanoP3 were engineered with unique immobilization capabilities facilitating multifunctional nanocarriers. The unique surface chemistry of nanoP3, allowing a robust immobilization of the cargo without the need for intermediate functionalization strategies, has great potential to overcome major limitations of currently proposed platforms. As many of the favorable characteristics of nanoP3 are inherent to the fabrication process, this work proposes PP as a nanoparticle synthesis route with valuable potential for broad clinical and commercial applications.
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GAO, YONG. "SURFACE MODIFICATION OF NANOPARTICLES AND CARBON NANOFIBERS BY PLASMA POLYMERIZATION AND PROPERTIES CHARACTERIZATION." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1091480190.
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Rau, Kaustubh R. "Surface modification of biomaterials by pulsed laser ablation deposition and plasma/gamma polymerization." [Gainesville, Fla.] : University of Florida, 2000. http://etd.fcla.edu/etd/uf/2000/ane5966/thesis.PDF.
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Thesis (Ph. D.)--University of Florida, 2000.Title from first page of PDF file. Document formatted into pages; contains xv, 221 p.; also contains graphics. Vita. Includes bibliographical references (p. 209-220).
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Yu, Qingsong. "Plasma deposition and treatment by a low temperature cascade arc torch /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9904876.
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Muir, Benjamin Ward. "Oxygen plasma treatment of polycarbonate for improved adhesion of plasma deposited siloxane thin films." Monash University, School of Physics and Materials Engineering, 2004. http://arrow.monash.edu.au/hdl/1959.1/9721.
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Fernandes, Rodrigo Sampaio. "Caracterização estrutural e propriedades óticas e mecânicas do diglime polimerizado a plasma /." Guaratinguetá : [s.n.], 2004. http://hdl.handle.net/11449/97117.
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Resumo: Esta dissertação de mestrado trata do estudo da caracterização estrutural, e de propriedades óticas e mecânicas do dietilenoglicoldimetiléter (DIGLIME) polimerizado via plasma. Este tipo de plasma produz filmes poliméricos com características físicas, químicas e biológicas semelhantes àquelas observadas em poli(óxido de etileno)- (PEO) e polietileno-glicol (PEG), que são polímeros produzidos através de processos químicos convencionais. Os polímeros a plasma foram obtidos usando descargas de rádio-freqüência operando em 13,56 MHz. Os parâmetros do processos de deposição utilizados foram potência de 10 a 40W e pressão de operação de 120 a 440 mTorr. A estrutura molecular dos polímeros foi estudada por espectroscopia infravermelha. De acordo com os resultados obtidos, baixas pressões e potências de RF produzem filmes poliméricos com características tipo PEO. A tensão mecânica residual nos filmes poliméricos foi investigada pelo método da deflexão de um feixe de laser. Os resultados indicaram tensões compressivas em todos os polímeros e boa estabilidade em função do tempo de envelhecimento. As propriedades óticas dos polímeros a plasma, como coeficiente de absorção, gap ótico e índice de refração foram investigadas através de espectroscopia ultravioleta-visível. O índice de refração calculado é próximo de 1,5 e o gap ótico decresce de 5,0 para 3,5 eV quando a potência de rádio-freqüência é aumentada de 10 para 40W .Abstract:This Mastering Dissertation deals with the study of structural characterization mechanical and optical properties of the diethyleneglycoldimethylether (diglime) polymerized by plasma. This kind of plasma produces polymer films with interesting physical, chemical and biological characteristics likely those observed in polyethylene-oxide (PEO) and polyethylene-glycol (PEG) that are polymers produced by conventional chemical processes. The plasma polymer films were obtained using 13.56 MHz radio-frequency discharges. The process parameters were RF power from 10 to 40W and operation pressure from 120 to 440 mTorr. The molecular structure of the films was investigate by infrared spectroscopy. According to the obtained results, low pressures and RF power discharges, produce polymer films with PEO-like characteristics. The residual mechanical stress in the films was investigated by the laser beam deflection method. The results indicated compressive stresses in all films and good stability as a time function. The optical properties of the plasma polymers such as absorption coefficient, optical gap and refractive index were investigated using ultraviolet-visible spectroscopy. The calculated refractive index is near 1.5 and the optical gap decreases from 5.0 to 3.3 eV as the RF power is increased from 10 to 40W.
Orientador: Rogerio Pinto Mota
Coorientador: Nilson Cristino da Cruz
Banca: Elson de Campos
Banca: Munemasa Machida
Mestre
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Ledernez, Loïc [Verfasser], and Gerald A. [Akademischer Betreuer] Urban. "Investigation of a magnetron enhanced AF plasma polymerization process for sensor coating = Untersuchung eines Magnetron-Angereicherten AF Plasma-Polymerisationsprozesses für Sensorbeschichtung." Freiburg : Universität, 2011. http://d-nb.info/1123463263/34.
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Fernandes, Rodrigo Sampaio [UNESP]. "Caracterização estrutural e propriedades óticas e mecânicas do diglime polimerizado a plasma." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/97117.
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Universidade Estadual Paulista (UNESP)
Esta dissertação de mestrado trata do estudo da caracterização estrutural, e de propriedades óticas e mecânicas do dietilenoglicoldimetiléter (DIGLIME) polimerizado via plasma. Este tipo de plasma produz filmes poliméricos com características físicas, químicas e biológicas semelhantes àquelas observadas em poli(óxido de etileno)- (PEO) e polietileno-glicol (PEG), que são polímeros produzidos através de processos químicos convencionais. Os polímeros a plasma foram obtidos usando descargas de rádio-freqüência operando em 13,56 MHz. Os parâmetros do processos de deposição utilizados foram potência de 10 a 40W e pressão de operação de 120 a 440 mTorr. A estrutura molecular dos polímeros foi estudada por espectroscopia infravermelha. De acordo com os resultados obtidos, baixas pressões e potências de RF produzem filmes poliméricos com características tipo PEO. A tensão mecânica residual nos filmes poliméricos foi investigada pelo método da deflexão de um feixe de laser. Os resultados indicaram tensões compressivas em todos os polímeros e boa estabilidade em função do tempo de envelhecimento. As propriedades óticas dos polímeros a plasma, como coeficiente de absorção, gap ótico e índice de refração foram investigadas através de espectroscopia ultravioleta-visível. O índice de refração calculado é próximo de 1,5 e o gap ótico decresce de 5,0 para 3,5 eV quando a potência de rádio-freqüência é aumentada de 10 para 40W .
This Mastering Dissertation deals with the study of structural characterization mechanical and optical properties of the diethyleneglycoldimethylether (diglime) polymerized by plasma. This kind of plasma produces polymer films with interesting physical, chemical and biological characteristics likely those observed in polyethylene-oxide (PEO) and polyethylene-glycol (PEG) that are polymers produced by conventional chemical processes. The plasma polymer films were obtained using 13.56 MHz radio-frequency discharges. The process parameters were RF power from 10 to 40W and operation pressure from 120 to 440 mTorr. The molecular structure of the films was investigate by infrared spectroscopy. According to the obtained results, low pressures and RF power discharges, produce polymer films with PEO-like characteristics. The residual mechanical stress in the films was investigated by the laser beam deflection method. The results indicated compressive stresses in all films and good stability as a time function. The optical properties of the plasma polymers such as absorption coefficient, optical gap and refractive index were investigated using ultraviolet-visible spectroscopy. The calculated refractive index is near 1.5 and the optical gap decreases from 5.0 to 3.3 eV as the RF power is increased from 10 to 40W.
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Peri, Someswara Rao. "Interface Structure of Photonic Films Created by Plasma Enhanced Chemical Vapor Deposition." University of Akron / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=akron1271687789.
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YANG, HAI. "PLASMA TREATMENT OF ORGANIC INHIBITORS FOR CORROSION PROTECTION OF AEROSPACE ALLOYS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1058383366.
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Oates, Thomas William Henry. "Metal plasma immersion ion implantation and deposition using polymer substrates." Connect to full text, 2003. http://hdl.handle.net/2123/571.
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Thesis (Ph. D.)--University of Sydney, 2004.Title from title screen (viewed 5 May 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Physics, Faculty of Science. Degree awarded 2004; thesis submitted 2003. Includes bibliographical references. Also available in print form.
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Mohamed, Alaa Fahmy Verfasser], and Jörg [Akademischer Betreuer] [Friedrich. "Plasma-Initiated Polymerization and Copolymerization and Analysis of Products / Alaa Fahmy Mohamed. Betreuer: Jörg Friedrich." Berlin : Universitätsbibliothek der Technischen Universität Berlin, 2011. http://d-nb.info/101653356X/34.
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CHASE, JENNIFER E. "SEMI-CONTINUOUS PLASMA POLYMERIZATION OF A FILM TO ENHANCE THE TEXTURE PROPERTIES OF AN ELASTOMER." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin975349091.
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Lima, Roberto da Rocha. "Polimerização por plasma de éter e ésteres orgânicos: caracterização e possíveis usos em microeletrônica." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-04082004-185245/.
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O presente trabalho teve por objetivo verificar a possibilidade de obtenção de filmes finos pela polimerização por plasma de éter etílico, acetato de metila e de etila, e testes dos referidos filmes quanto à possibilidade de adsorção de compostos orgânicos polares, pois filmes adsorventes podem ser usados na construção de sensores e pré-concentradores. Utilizou-se para a polimerização por plasma os reagentes puros, mistura de éter etílico com oxigênio ou acetona ou os acetatos de metila e etila. Em todos os casos obtiveram-se filmes sobre substrato de silício e estes filmes apresentaram pouco ou nenhum descolamento por cerca de um ano. Os filmes foram caracterizados por perfilometria, para determinar a taxa de deposição, por espectroscopia de infravermelho, para avaliar as espécies polares e medida de ângulo de contato com uma gota de 4 µL de água destilada e soluções aquosas de 2-propanol ou acetona, para comprovar o caráter hidrofílico e organofílico, respectivamente. Os filmes a base de éter etílico apresentaram taxas de deposição entre 80 e 300 Å/min, além de alta intensidade relativa da banda de OH, medida por espectroscopia de infravermelho. Os ângulos de contato ficaram próximos a 75°, mostrando uma superfície hidrofílica. Adição de oxigênio ao plasma favoreceu a oxidação da molécula, conseqüente formação de CO e aumento da medida de ângulo de contato. Acetona, por sua vez, além de favorecer a produção de CO aumenta a formação de particulados e a medida de ângulo de contato. Deposição em câmara fechada favorece o aumento da taxa de deposição e formação de OH, além de pequena diminuição da medida de ângulo de contato. Adições dos acetatos de metila e/ou etila torna o sistema complexo e de difícil controle. Para os ésteres obteve-se janela de processo estreita, onde para acetato de metila observaram-se taxas de deposição maiores e medidas de ângulo de contato menores, entre 160 e 510 Å/min, e 54° a 68°, respectivamente, o que prova que a superfície é hidrofílica. A espectroscopia de infravermelho mostrou bandas semelhantes às bandas encontradas para éter etílico. Deposição em câmara fechada aumentou a taxa de deposição e favoreceu a diminuição das medidas de ângulo de contato. No plasma de acetato de etila observaram-se taxas de deposição alta e ângulos de contato intermediários entre filmes a base de éter etílico e acetato de metila, entre 350 e 1200 Å/min, e 61° a 72°, respectivamente. A superfície é hidrofílica e a espectrocopia de infravermelho mostrou bandas semelhantes às bandas encontradas para éter etílico, porém a banda CO apresenta alta intensidade relativa. A deposição em câmara fechada aumentou a taxa de deposição e a intensidade relativa de CO, obtendo-se ângulos de contato menores se comparados aos da deposição em fluxo contínuo.A medida de ângulo de contato para soluções aquosas de 2-propanol e acetona mostrou que os filmes são organofílicos e que apresentam maior afinidade por 2-propanol. A deposição sobre estrutura padrão em alumínio mostrou boa conformidade de degrau para todos os filmes. Medidas em microbalança de quartzo mostraram que os filmes adsorvem compostos orgânicos polares. Deposição dos filmes de éter e ésteres sobre filme a base de hexametildissilazana mostrou a formação de um filme contínuo, mas que rapidamente apresenta estresse, apesar de não ocorrer descolamento. A deposição sobre placas planas de acrílico mostrou um filme aderente tanto para éter etílico quanto para os ésteres. Estes filmes se apresentam hidrofílicos e organofílicos. Microcanais usinados em acrílico demonstraram a possibilidade do uso do filme na produção de estruturas pré-concentradoras.The aim of this work is to characterize thin films obtained by plasma polymerization of ethyl ether, ethyl or methyl acetate. The films were tested for adsorption of polar organic compounds in order to evaluate their use for sensors or preconcentrators manufacturing. It was tried plasma polymerization of pure reactants and mixtures of ethyl ether with oxygen, acetone, methyl or ethyl acetate. For all reactants and mixtures films were obtained on silicon and peeling did not occur during one year of observation. Measurements of profilemeter, infrared spectroscopy, contact angle for drop of water, 2-propanol and acetone aqueous solutions were used to determine deposition rate, polar species and hydrophilic or organophilic character, respectively. For ethyl ether the films show a deposition rate between 80 and 300 Å/min and high OH relative intensity. Water contact angles were approximately 75º for all films, therefore the surfaces are hydrophilic. Oxygen addition to the plasma favors ethyl ether oxidation, increase in CO relative intensity and water contact angle. Acetone addition favors rise not only in CO relative intensity and water contact angle but also in particle formation. Deposition on closed chamber mode favors the increase of deposition rate and OH formation but the diminish on water contact angle. Mixture with methyl or ethyl acetate turns the system complex and difficult to control. The acetates process window acetates were narrow but presented higher deposition rates, from 160 A/min to 510 A/min, and lower water contact angles, from 54 º to 68º. Infrared spectroscopy shows the same species found for ethyl ether deposition. Deposition on closed chamber mode increases deposition rate and decreases the water contact angle. Ethyl acetate plasmas show high deposition rate but low water contact angle values when compared to methyl acetate. The deposition rates and water contact angles lie between 350 and 1200 A/min and 61º and 72º, respectively. Infrared spectroscopy shows the same species found on ethyl ether deposition but co presents high relative intensity. Deposition on closed chamber mode not only rises the deposition rate and CO relative intensity but also lowers the water contact angle. Contact angle measurements for 2-propanol and acetone aqueous solution show the surface is organophilic and show bigger affinity for 2-propanol aqueous solution. Deposition on aluminum lines deposited on silicon shows conformal deposition for all films. Quartz crystal measurements show the films adsorb polar organic compounds. Plasma deposited ethyl ether, methyl or ethyl acetate films on plasma deposited hexametyldisilazane substrates showed a continuous film that easily stress, although peeling was not observed. Deposition on poly(methyl methacrylate) showed good adhesion for all films. These films are also hydrophilic and organophilic. Micromachinned microchannels showed the possibility of adsorption and preconcentrators development.
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Mertens, Jeremy. "Atmospheric plasma treatment of aluminum alloy surfaces: Oxide growth and oxygen rich organic coating deposition." Doctoral thesis, Universite Libre de Bruxelles, 2019. https://dipot.ulb.ac.be/dspace/bitstream/2013/287803/3/these.pdf.
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L’objectif de cette thèse consiste en une étude fondamentale de différentes approches pour la modification de surfaces d’alliages d’aluminium. Elle s’inscrit dans le cadre du projet FLYCOAT, subventionné par la région Wallonne. Ce dernier avait pour objectif le développement d’alternatives au couplage classique d’un procédé d’anodisation utilisant des bains de Cr (VI) aux résines époxy pour la protection des alliages d’aluminium contre la corrosion. Dans un premier temps, la synthèse par plasma atmosphérique dans un réacteur de type décharge à barrière diélectrique (DBD) de films riches en groupements carboxyliques à partir de 8 précurseurs organiques est étudiée. Une attention particulière est portée à la compréhension fondamentale des mécanismes de polymérisation de ces précurseurs. L’influence significative de minimes variations de la structure chimique du précurseur est étudiée. Concrètement, nous démontrons l’impact de la présence et de la position de doubles liaisons ou encore le ratio C/O dans le monomère injecté sur le mécanisme de synthèse des couches déposées. Pour ce faire, une méthodologie combinant des analyses de la phase plasma et des films déposés est proposée. Les propriétés électriques de la DBD d’argon sont évaluées par oscilloscope avant et durant l’injection des différents précurseurs. La quantité d’énergie transférée de la décharge vers le précurseur est évaluée par spectroscopie d’émission optique et corrélée à sa structure. Une fragmentation réduite est mise en évidence par spectrométrie de masse pour les monomères contenant une double liaison. Ces analyses de la phase plasma sont alors corrélées avec les propriétés physiques et chimiques des films synthétisés. Les compositions chimiques de surface et de la matrice des couches minces sont étudiées par spectroscopie à photoélectrons X (XPS) et infrarouge. Le rôle essentiel de la présence et de la position de la double liaison dans la molécule injectée est démontré. Les vitesses de dépôt et la rugosité des films déposés par plasma atmosphérique avec l’injection des 8 précurseurs sont évaluées par profilométrie à stylet. Dans la seconde partie, le couplage de deux méthodes de plasma atmosphérique est proposé pour la synthèse de couches d’alumine aux propriétés adaptables. Le premier traitement consiste en un nombre varié de passages d’une torche plasma opérant dans un régime d’arc. L’effet du nombre de passages sur les propriétés physiques et chimiques du substrat est étudié par XPS, angle de contact, microscopie électronique à balayage et mesures de diffraction à rayons X. Une corrélation est suggérée entre le nombre de passages de la torche et les propriétés électrochimiques du substrat. L’influence de ce premier traitement sur les propriétés de la couche d’oxyde d’aluminium synthétisée par oxydation par plasma électrolytique est mise en évidence. Dans un troisième temps, le plasma pouvant être considéré comme un réservoir d’énergie, une étude de faisabilité est réalisée afin d’évaluer sa potentielle utilisation pour la réticulation d’une résine de type benzoxazine. L’efficacité du traitement par DBD atmosphérique d’argon ou hélium est comparée et discutée.Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Wolf, Marcus. "Plasmaabscheidung von Metall-Polymer-Nanokompositen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-69923.
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Das Ziel der vorliegenden Arbeit war die Entwicklung eines neuartigen Abscheideverfahrens für Dünnschichten aus Polymer-Metall-Nanokompositen sowie die Charakterisierung sensorischer und antibakterieller Eigenschaften von ersten, mit diesem System abgeschiedenen Komposit-Schichten . Durch den Einbau eines rotierenden Probenhalters zwischen den beiden Plasmaquellen ist es möglich, Plasmapolymere und metallische Nanopartikel als Einzelschichten, Komposite oder Multischichten abzuscheiden. Mit der Gasflusssputterquelle werden Silber-Nanopartikel einer Größe von 1,8…20 nm mit einer Verteilungsbreite der gewichteten Normalverteilung von 0,1…2,7 nm durch Kathodenzerstäubung und anschließende Agglomeration der Cluster in der Gasphase generiert. Die Entladungsbedingungen, welche durch die Elektronentemperatur und -dichte charakterisiert werden, zeigen eine sprunghafte Änderung bei Drücken von 70…85 Pa und einer Spannung von 550 V. Ab einem Gasfluss von 3 slpm kehrt sich die Proportionalität zwischen zugeführter elektrischer Leistung und Elektronentemperatur um. Dies wird durch die vermehrte Emission von Sekundärelektronen erklärt. Die abgeschiedenen Partikel sind aus verschieden orientierten Clustern aufgebaut. Durch Kühlung des Substrates wurde nachgewiesen, dass eine Agglomeration auf dem Substrat nur bei Gasflüssen von 5 slpm stattfindet. Anhand der Auswertung von faktoriellen Versuchsplänen wurde gezeigt, dass der Gasfluss auf die Partikelgröße und Abscheiderate den größten Einfluss hat. Die Präkursoren Styrol, Methylmethacrylat und 3-Methyl-1,2-butadien wurden durch Plasmapolymerisation in einer 60 MHz-Linearquelle als dünne, homogene Schichten im nm-Bereich abgeschieden. Aus den Emissionsspektren von Argon konnten, unter Verwendung des Stoß-Strahlungs-Modells, Elektronendichten von 6*1010…1,5*1011 cm-3 und Elektronentemperaturen von 3…9 eV in Abhängigkeit von der Verweilzeit der Monomermoleküle im Plasma sowie des Energieeintrages berechnet werden. Die Elektronen haben bei Energieeinträgen oberhalb von 6*107 J/kg genügend Energie, um -Bindungen des Kohlenstoffs in der Gasphase zu spalten. Die freien Radikale initiieren Oxidationsreaktionen, was zur Bildung von Carbonylverbindungen in Schichten aus Styrol- und Isoprenplasmapolymeren führt. Die mit XPS-Messungen gefundenen hohen Sauerstoffgehalte der Plasmapolymer-Schichten konnten durch Kontaktwinkelmessungen bestätigt werden. Die Quellungsmessungen in organischen Lösungsmitteln (Aceton, Ethanol, Chloroform, Toluol) mit reflektometrischer Interferenzspektroskpie bestätigen die Tendenzen der Kontaktwinkelmessung im Fall von Styrol und Methylmethacrylat. Die Abscheiderate der Plasmapolymere wird besonders durch den Energieeintrag beeinflusst. Dabei zeigt sich nur bei Isopren eine deutliche Auswirkung der Abbaureaktionen.Die Härte der Isopren-Schichten korreliert ebenfalls mit der Elektronendichte. Die Perkolationsschwelle der Silber-Plasmapolymer-Nanokomposite liegt bei einem Füllgrad von 57 %, was typisch für Partikel mit geringem Aspektverhältnis ist. Die Schichten reagieren selektiv auf Dämpfe der Lösungsmittel. Bisher war die Langzeitstabilität von Membranen zur Trinkwasseraufbereitung durch Ultrafiltration durch das starke Wachstum von Mikroorganismen auf der Membranoberfläche eingeschränkt. Dies konnte durch die Beschichtung mit Silber-MMA-Kompositen verbessert werden. Durchflussmessungen an behandelten Membranen sowie elektronenmikroskopische Aufnahmen bestätigen die gute antibakterielle Wirkung der Beschichtung.
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Merche, Delphine. "Synthèse et caractérisation de couches de polystyrène et de polystyrène sulfoné obtenues par polymérisation-plasma à pression (sub)-atmosphérique." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209871.
Full textAbstract:
Lors de ce travail, de fins films de polystyrène ont été déposés dans la post-décharge d’une torche plasma atmosphérique commerciale, mais aussi dans la décharge d’une DBD (Décharge à Barrière Diélectrique), conçue et développée par nos soins au laboratoire. Une DBD est un procédé permettant d’obtenir des plasmas froids à pression atmosphérique. Nos résultats ont montré que la DBD permettait d’obtenir des films de polystyrène de meilleure qualité (degré d’oxydation moindre…) qu’avec la torche commerciale en raison de l’atmosphère contrôlée de l’enceinte DBD. Les films sont déposés en présence d’un gaz porteur (Ar ou He dans la DBD). Nous avons pu mettre en évidence l’influence de la nature de ce gaz porteur sur la structure des films (degré de branchement, et de réticulation des films et de préservation des cycles aromatiques de la molécule de départ).
Les dépôts de polystyrène sulfoné ont été synthétisés dans la DBD en une seule étape, par « copolymérisation » de deux précurseurs (styrène et acide trifluorométhane sulfonique) injectés simultanément dans la décharge. Ces membranes pourraient servir d’électrolyte dans les piles à combustibles miniaturisées de type PEMFC (« Polymer Electrolyte Membrane Fuel Cell »), utilisant de l’hydrogène ou du méthanol et ce pour des applications portables.
L’acide trifluorométhane sulfonique permet le greffage de groupements sulfoniques échangeurs d’ions (nécessaires pour la conductivité de la membrane) sur le squelette de polystyrène.
La complémentarité des différentes techniques spectroscopiques utilisées -Spectroscopie des Photoélectrons X (XPS), Infra-Rouge à Transformée de Fourier (FTIR), Spectroscopie des Ions Secondaires (SIMS) statique et dynamique- ont montré que les groupements acides sulfoniques (bien préservés dans la décharge à pression sub-atmosphérique) étaient bien greffés dans la matrice de polystyrène, et ce sur toute l’épaisseur de la membrane. L’influence des paramètres (température de l’acide, tension appliquée entre les électrodes, nature du gaz porteur…) sur la quantité de groupements ionisables greffés, sur la vitesse de dépôt et aussi sur la morphologie des films a été étudiée respectivement par XPS et par microscopie.
En plus des dépôts sur substrats usuels (Si, acier…) utilisés pour les caractérisations chimiques, nous avons synthétisé les films directement sur des électrodes de carbone enrichies en platine.
Nous avons déposé le catalyseur à partir d’une solution colloïdale de platine nébulisée dans la post-décharge d’une torche plasma atmosphérique sur des couches de carbones poreuse et sur du carbone vitreux (utilisé comme modèle pour le profilage par SIMS dynamique) dans différentes configurations et ce pour différents paramètres afin de constituer des électrodes servant de substrat pour l’adhésion de la membrane-plasma pour des perspectives d’assemblage membrane-électrodes pour PAC. /
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Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Nielsen, Lynette D. "A comparative study of plasma-induced polymerization and plasma-state polymerization of acrylonitrile for modification of cellophane." 1996. http://catalog.hathitrust.org/api/volumes/oclc/35860088.html.
Full textAbstract:
Thesis (Ph. D.)--University of Wisconsin--Madison, 1996.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 198-205).