Dissertations / Theses on the topic 'Plasma deposits'

High field strength elements (HFSE) are geologically and economically important. These elements were once thought to be immobile during metasomatic processes, however, a growing body of empirical evidence indicates that HFSE can be mobilized under certain conditions. Despite this evidence, little is known about the factors controlling solubility, transport and deposition of HFSE by aqueous fluids, apart from some theoretical estimates and rare experimental studies. Therefore, the study of natural systems (e.g., HFSE ore deposits) provides an excellent opportunity to evaluate HFSE mobility by aqueous fluids. Five localities where evidence of hydrothermal transport of HFSE has been previously documented were included in this study: Gallinas Mountains, New Mexico; South Platte, Colorado; Rock Canyon Creek, British Columbia; St. Lawrence, Newfoundland; and Strange Lake, Quebec/Labrador. Minerals and, in the case of South Platte, fluid inclusions from these localities were analyzed using petrography and laser ablation inductively-coupled plasma mass spectrometry (LA-ICPMS) to evaluate the source of the HFSE and the hydrothermal fluids responsible for HFSE transport, and factors controlling HFSE and gangue mineral (e.g., fluorite, quartz) precipitation. Analysis of some of the important gangue minerals, which are also the primary host of fluid inclusions in many of these deposits (e.g., fluorite), is difficult using 266 nm Nd:YAG-based LA-ICPMS. Furthermore, complex mineral intergrowths and the desire to quantify the chemical composition of unknown minerals required the development of analytical and data reduction protocols for LA-ICPMS. Methods for conducting traversed opening of fluid inclusions, removing the host mineral contribution to fluid inclusion signals by calculating count rate ratios, and quantifying the composition of minerals without using an internal standard are presented. In general, hydrothermal enrichment of HFSE in these deposits appears to have resulted from interaction of an HFSE- and F-bearing magmatic fluid with another, Ca-bearing fluid or with Ca-bearing wall rocks or preexisting minerals. In most cases, HFSE appear to be derived locally, within the associated igneous intrusion.

Le traitement des eaux industrielles usées est un enjeu pour la société. Notamment, les colorants très utilisés dans les produits manufacturés sont des polluants pour nos sources d'eau. Ce travail de thèse porte sur la dégradation de colorant(s) par un système de couche mince nanocomposite cuivre/carbone. Nos nanocomposites ont été élaborés grâce à un procédé plasma par pulvérisation cathodique en atmosphère réactive de cyclohexane (ou procédés hybride PVD/PECVD dépendant). Des études par spectroscopie d'émission optique et spectrométrie de masse ont été menées afin d'analyser le plasma lors de la phase de dépôt. Après leur synthèse, nos couches minces ont été caractérisées d'un point de vue structural (morphologie et microstructure), optique et électrique en fonction de différents paramètres de dépôt. Dans ce travail, le polluant utilisé est le carmin d'indigo classé dans la famille des indigoïdes célèbre pour la couleur bleu des jeans. Le suivi de la dégradation de ce colorant en solution aqueuse a été réalisé par spectrophotométrie UV-visible. Nos nanocomposites ont pu décolorer les solutions lors d'une illumination par une lampe halogène ou lors d'une phase de chauffage. Nous nous sommes intéressés à l'étude thermique de ce phénomène en fonction de différents paramètres (température, concentration initiale,…) et aux modèles thermodynamiques de cette réaction (Eyring et Arrhénius). Pour justifier la dégradation du colorant, un électro-nébuliseur couplé à un spectromètre de masse a été utilisé. Cette expérimentation montre que la molécule de carmin d'indigo a subi une perte de masse et que nos matériaux se comportent bien en catalyseurs
The treatment of industrial wastewater is an issue for the society. For instance, used dyes in manufactured products are pollutants for our waters sources. The thesis work focuses on dye degradation by thin films of copper/carbon nanocomposite. Our nanocomposites have been elaborated through a plasma method by a cathodic sputtering in reactive atmosphere of cyclohexane (hybrid process of PVD/PECVD). Studies by optical emission spectroscopy and mass spectroscopy have been carried out in order to analyze the plasma during the deposition. After elaboration, our thin films have been characterized from a structural (morphology and microstructure), electrical and optical point of view as a function of deposit parameters. In this work, we used indigo carmine as a pollutant. The dye belongs to the indigoid family and is commonly used for the blue color of jeans. The degradation of this dye in aqueous solutions has been monitored by UV-Visible spectrophotometry. Our nanocomposites have been able to discolour solutions by halogen lamp illumination or during moderate heating. The investigation focused on the thermal aspects of this phenomenon as a function of several parameters (temperature, initial concentration,…) with the help of thermodynamic models such as Arrhenius and Eyring. To justify the degradation of the dye, an electrospray ionization mass spectrometer has been used. It revealed that the molecule of indigo carmine underwent a loss of mass and that our materials perform as catalysts

Bacterial infection is a growing concern in hospital and community settings, where the issue of biofilms is a major problem. Most current methods of preventing microbial attachment and biofilm formation are limited due to application, process or inherent flaws. It was proposed that thin films containing an organometallic element could be deposited using plasma, a quick, clean surface modification technique; to create antimicrobial films which could then be applied to a range of substrates.
Several novel antimicrobial monomer systems were synthesised and characterised based on silver, copper and zinc as the active constituent with phosphines, phosphites, maleimide and a novel Schiff base among the ligand systems. All monomers were found to greatly inhibit the growth of P. aeruginosa and S. aureus in solution and on solid media. Successful monomers were deposited onto suitable substrates (glass, gold, plastics, non-woven polypropylene) using continuous wave and pulse plasma, with the films characterised and low levels of active metal found in analysis using XPS and SIMS. Films were tested against solutions of pathogenic bacteria using a number of traditional and modern microbiological techniques and found to inhibit growth under a range of conditions, potentially due to the synergistic action of metal and ligand on bacterial cells. Effective control of bacteria was exhibited at times varying from 1h to 24h+. Highly volatile compounds were produced which allowed quick deposition of plasma films, which showed excellent activity against bacteria (99.9%+ growth reduction), indicating viability for potential application. All films tested showed no inhibition or toxicity to eukaryotic cells.

Hexagonal boron nitride (h-BN) thin films are deposited by plasma enhanced chemical vapor deposition (PECVD). Effects of heat treatment and source gases on the structure and physical properties are investigated. Chemical bonding is analyzed in comparison with the better understood isoelectronic carbon compound, graphite. It seems that the basic difference between h-BN and graphite arises from the different electronegativities of boron and nitrogen atoms. Optical absorptions in UV-visible range for crystalline and amorphous structures are outlined. The expressions used for the evaluation of mechanical stress induced in thin films are derived. The deposited films are considered to be turbostratic as they do not exhibit the characteristic optical absorption spectra of a crystal. A new system, stylus profilometer, is implemented and installed for thin film thickness and mechanical stress measurements. Hydrogen atom density within the films, estimated from FTIR spectroscopy, is found to be a major factor affecting the order and mechanical stress of the films. Heat treatment of the films reduces the hydrogen content, does not affect the optical gap and slightly increases the Urbach energy probably due to an increased disorder. Increasing the nitrogen gas flow rate in the source gas results in more ordered films. The virtual crystal of these films is detected to be unique. Relative bond concentrations of the constituent elements indicate a ternary boron-oxygen-nitrogen structure. The physical properties of h-BN such as high resistivity and wide band gap seem suitable for optoelectronic applications such as gate dielectrics in thin film transistors and light emitting devices in the blue region.

Optical diagnostics on fusion devices are important for both research and real time control. All of these diagnostics depend on reflective optics in the form of metallic mirrors. Etching and re-deposition during fusion operation from the beryllium inner wall onto the mirrors can cause severe degradation in the reflectivity. Using the mirror as the powered electrode to form a capacitively coupled plasma above the surface is seen as the most favourable method for recovery of the mirror reflectivity. The ions created within the plasma can bombard the surface and remove the deposit. This method has been tested experimentally in various ways and in various geometries and has been proven to work in these cases. However, in order to optimise the system modelling efforts are carried out within this thesis. The Hybrid Plasma Equipment Model (HPEM) is configured to simulate the etching plasma and is benchmarked against experimental results. After successful benchmarking parameters are varied in an attempt to find optimum settings for the successful implementation of this method on ITER. Results concluding that individual mirrors require individual modelling efforts as trends cannot necessarily be applied to each mirror geometry. A beryllium/argon/oxygen gas chemistry set is created to more accurately model the ITER environment which is compared with a published aluminium/argon/oxygen set. Aluminium is currently used as a proxy for beryllium in the majority of experimental work. They are shown to be dissimilar in their behaviour within a bulk Ar plasma which will have knock on effects for the etching process. The bulk plasma properties remain identical at low fractions of Be or Al. Also presented is work involving understanding the mechanism behind modification of polypropylene using an atmospheric-pressure plasma jet. A two stage process is identified involving atomic oxygen from the jet and nitrogen from the surrounding atmosphere.

[Truncated abstract] This study investigates the thermal stability of Plasma Enhanced Chemical Vapor Deposited (PECVD) silicon nitride thin films. Effects of heat-treatment in air on the chemical composition, atomic bonding structure, crystallinity, mechanical properties, morphological and physical integrity are investigated. The chemical composition, bonding structures and crystallinity are studied by means of X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR) Spectroscopy and Transmission Electron Microscopy (TEM). The mechanical properties, such as hardness and Young’s modulus, are determined by means of nanoindentation. The morphological and physical integrity are analyzed using Scanning Electron Microscopy (SEM) . . . The Young’s modulus (E) and hardness (H) of the film deposited at 448 K were measured to have E=121±1.8 GPa and H=11.7±0.25 GPa. The film deposited at 573 K has E=150±3.6 GPa and H=14.7±0.6 GPa. For the film deposited at 573 K, the Young’s modulus is not affected by heating up to 1148 K. Heating at 1373 K caused significant increase in Young’s modulus to 180∼199 GPa. This is attributed to the crystallization of the film. For the film deposited at 448 K, the Young’s modulus showed a moderate increase, by ∼10%, after heating to above 673 K. This is consistent with the much lower level of crystallization in this film as compared to the film deposited at 573 K. In summary, low temperature deposited PECVD SiNx films are chemically and structurally unstable when heated in air to above 673 K. The main changes include oxidation to SiO2, crystallization of Si3N4 and physical cracking. The film deposited at 573 K is more stable and damage and oxidation resistant than the film deposited at 448 K.

Ti-V-Zr-Nb-Hf metallic and nitride films were deposited by filtered vacuum arc plasma from a single equiatomic HEA cathode. The composition, microstructure, mechanical properties, thermal stability and corrosion properties were investigated. The deposited metallic film has a two-phase structure with bcc and hcp-lattice. The nitride films were found to have only an fcc structure. All coatings have nano-grained structures, with grain sizes 5 nm for metallic and 36 nm for nitride. The nitride coatings have a compressive stress of around – 12,5 GPa, high hardness ~ 40 GPa and elastic modulus ~ 450 GPa. After annealing in vacuum in range 400-1200 °C, 3 h for every temperature, hardness decreased to 25 GPa. It was found that both the metallic and nitride coatings exhibited their best corrosion resistance than steel samples in a 3,5 wt. % NaCl solution. The metallic coatings showed better corrosion resistance than the nitride coatings. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35323

Les infections associées au milieu hospitalier demeurent une cause majeure de mortalité et de morbidité dans le monde, malgré plusieurs décennies dédiées à promouvoir une meilleure surveillance et des méthodes de désinfection plus complètes. La capacité des bactéries pathogènes à survivre sur des substrats solides a été identifiée comme un facteur clé de la pathogenèse de ces infections, en multipliant les sources de transmission et de contamination. Au niveau de la recherche, cette situation s’est récemment traduite par un intérêt marqué pour le développement de revêtements antibactériens novateurs pouvant constituer une ligne de défense complémentaire contre la colonisation bactérienne de surfaces, pourvu qu’ils puissent résister à l’environnement rigoureux des établissements de santé. Dans cette thèse, nous avons émis l'hypothèse qu'un revêtement antibactérien avec une stabilité supérieure pouvait être déposé en utilisant un procédé plasma modulable, de sorte que les propriétés du revêtement résultant pourraient être adaptées aux exigences de différentes situations ou applications. Par conséquent, des revêtements nanocomposites de carbone amorphe adamantin contenant de l'argent (Ag-DLC) ont été développés et étudiés comme plate-forme polyvalente pour des surfaces antibactériennes. L’intérêt de ce matériau réside dans la combinaison des excellentes propriétés mécaniques, de la résistance à l'usure et de l'inertie chimique du carbone amorphe adamantin avec les propriétés antibactériennes à large spectre des nanomatériaux d'argent au sein d’un même revêtement déposé par plasma. Ce travail a d'abord identifié les défis de conception spécifiquement associés au développement de revêtements antibactériens pour le milieu hospitalier. Des analyses approfondies des revêtements Ag-DLC ont ensuite démontré une bonne efficacité antibactérienne in vitro ainsi qu’une stabilité des propriétés, de la structure et de l’état chimique des revêtements dans le temps. L'étendue de la polyvalence des revêtements Ag-DLC a été évaluée au travers de l’identification des mécanismes de croissance principaux, permettant d’obtenir des informations essentielles sur la façon dont les propriétés des films, telles que la dureté, la teneur et la distribution d’argent, pouvaient être contrôlées en ajustant des paramètres spécifiques du dépôt plasma. De plus, un traitement de surface in situ a été développé pour surmonter les problèmes de délamination et a montré la capacité de favoriser l'adhérence de revêtements DLC sur des substrats métalliques. Dans l'ensemble, cette étude a mis en évidence l'importance de la stabilité dans l'application des revêtements antibactériens et a démontré le vaste potentiel des procédés plasma pour le dépôt de revêtements antibactériens stables avec des propriétés adaptables.
Les infections associées au milieu hospitalier demeurent une cause majeure de mortalité et de morbidité dans le monde, malgré plusieurs décennies dédiées à promouvoir une meilleure surveillance et des méthodes de désinfection plus complètes. La capacité des bactéries pathogènes à survivre sur des substrats solides a été identifiée comme un facteur clé de la pathogenèse de ces infections, en multipliant les sources de transmission et de contamination. Au niveau de la recherche, cette situation s’est récemment traduite par un intérêt marqué pour le développement de revêtements antibactériens novateurs pouvant constituer une ligne de défense complémentaire contre la colonisation bactérienne de surfaces, pourvu qu’ils puissent résister à l’environnement rigoureux des établissements de santé. Dans cette thèse, nous avons émis l'hypothèse qu'un revêtement antibactérien avec une stabilité supérieure pouvait être déposé en utilisant un procédé plasma modulable, de sorte que les propriétés du revêtement résultant pourraient être adaptées aux exigences de différentes situations ou applications. Par conséquent, des revêtements nanocomposites de carbone amorphe adamantin contenant de l'argent (Ag-DLC) ont été développés et étudiés comme plate-forme polyvalente pour des surfaces antibactériennes. L’intérêt de ce matériau réside dans la combinaison des excellentes propriétés mécaniques, de la résistance à l'usure et de l'inertie chimique du carbone amorphe adamantin avec les propriétés antibactériennes à large spectre des nanomatériaux d'argent au sein d’un même revêtement déposé par plasma. Ce travail a d'abord identifié les défis de conception spécifiquement associés au développement de revêtements antibactériens pour le milieu hospitalier. Des analyses approfondies des revêtements Ag-DLC ont ensuite démontré une bonne efficacité antibactérienne in vitro ainsi qu’une stabilité des propriétés, de la structure et de l’état chimique des revêtements dans le temps. L'étendue de la polyvalence des revêtements Ag-DLC a été évaluée au travers de l’identification des mécanismes de croissance principaux, permettant d’obtenir des informations essentielles sur la façon dont les propriétés des films, telles que la dureté, la teneur et la distribution d’argent, pouvaient être contrôlées en ajustant des paramètres spécifiques du dépôt plasma. De plus, un traitement de surface in situ a été développé pour surmonter les problèmes de délamination et a montré la capacité de favoriser l'adhérence de revêtements DLC sur des substrats métalliques. Dans l'ensemble, cette étude a mis en évidence l'importance de la stabilité dans l'application des revêtements antibactériens et a démontré le vaste potentiel des procédés plasma pour le dépôt de revêtements antibactériens stables avec des propriétés adaptables.
Healthcare-associated infections remain a major cause of mortality and morbidity worldwide, with a substantial financial burden on society, despite decades of monitoring and disinfection efforts. The ability of pathogenic bacteria to survive on solid substrates has emerged as a key contributing factor in the pathogenesis of these infections by multiplying the sources of transmission and contamination. This has prompted investigations into the development of innovative antibacterial coatings, which could provide a complementary barrier against bacterial colonization of surfaces provided that they can withstand the harsh operating environment of healthcare facilities. In this thesis, we hypothesized that an antibacterial coating with superior stability could be deposited using a tailorable plasma process, so that the resulting coatings’ properties could be adapted to match the requirements of different situations or applications. Therefore, silver-containing diamond-like carbon (Ag-DLC) nanocomposite coatings were developed and investigated as a versatile platform material for antibacterial surfaces. The interest of this material lies in the combination of the excellent mechanical properties, wear-resistance and chemical inertness of diamond-like carbon with the broad-spectrum antibacterial properties of silver nanomaterials in a single, plasma-deposited coating. This work first identified the specific design challenges associated with the development of antibacterial coatings for healthcare environments. Thorough investigations of Ag-DLC coatings then revealed good antibacterial efficacy in vitro as well as stability of the coatings’ properties, structure, and chemistry over time. The extent of the tailorability of Ag-DLC coatings was also assessed through the identification of the main growth mechanisms, providing insights on how the film’s properties, such as the hardness, silver content, and silver distribution, could be controlled by adjusting specific plasma deposition parameters. Furthermore, an in situ interface plasma treatment was developed to overcome delamination issues and showed the ability to promote the adhesion of high stress DLC coatings on metallic substrates. Overall, this study highlighted the importance of stability in the application of antibacterial coatings and demonstrated the vast potential of plasma processes for the deposition of stable antibacterial coatings with tunable properties.
Healthcare-associated infections remain a major cause of mortality and morbidity worldwide, with a substantial financial burden on society, despite decades of monitoring and disinfection efforts. The ability of pathogenic bacteria to survive on solid substrates has emerged as a key contributing factor in the pathogenesis of these infections by multiplying the sources of transmission and contamination. This has prompted investigations into the development of innovative antibacterial coatings, which could provide a complementary barrier against bacterial colonization of surfaces provided that they can withstand the harsh operating environment of healthcare facilities. In this thesis, we hypothesized that an antibacterial coating with superior stability could be deposited using a tailorable plasma process, so that the resulting coatings’ properties could be adapted to match the requirements of different situations or applications. Therefore, silver-containing diamond-like carbon (Ag-DLC) nanocomposite coatings were developed and investigated as a versatile platform material for antibacterial surfaces. The interest of this material lies in the combination of the excellent mechanical properties, wear-resistance and chemical inertness of diamond-like carbon with the broad-spectrum antibacterial properties of silver nanomaterials in a single, plasma-deposited coating. This work first identified the specific design challenges associated with the development of antibacterial coatings for healthcare environments. Thorough investigations of Ag-DLC coatings then revealed good antibacterial efficacy in vitro as well as stability of the coatings’ properties, structure, and chemistry over time. The extent of the tailorability of Ag-DLC coatings was also assessed through the identification of the main growth mechanisms, providing insights on how the film’s properties, such as the hardness, silver content, and silver distribution, could be controlled by adjusting specific plasma deposition parameters. Furthermore, an in situ interface plasma treatment was developed to overcome delamination issues and showed the ability to promote the adhesion of high stress DLC coatings on metallic substrates. Overall, this study highlighted the importance of stability in the application of antibacterial coatings and demonstrated the vast potential of plasma processes for the deposition of stable antibacterial coatings with tunable properties.

The Fäboliden gold deposit is an ore body in northern Sweden’s Bothnian Basin and has been the subject of studies and test mining since the early 2000s when the Gold Line, an area of anomalously high-Au glacial till in Northern Sweden, became a center of economic interest. The deposit is a hypozonal orogenic gold deposit that displays many characteristic features of ore bodies of this type, including the presence of compound sulfide grains composed of a core of löllingite surrounded by a rim of arsenopyrite, and an abundance of pyrrhotite throughout the deposit and surrounding alteration zone. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to first map the distribution of trace elements in several of the arsenpyrite-löllingite grains, then to perform spot analyses of pyrrhotite grains in samples from across the distal and proximal alteration zones of the deposit. The maps of the trace elements in the compound löllingite-arsenopyrite grains show that: As and Au are found in greater abundance in the löllingite than in the arsenopyrite; Cu, Fe, S, and Ti are found in greater abundance in the arsenopyrite than in the löllingite; and Ag, Au, Bi, La, Mn, Pb, Sr, Ti and Tl are found in zones of secondary enrichment along fractures within the grains. Uranium and V may also be enriched along fractures, although this isn’t clear on all of the maps. Gold is an element of particular interest, because its distribution throughout the sulfide phases can be used to constrain the mechanism and relative timing of mineralization within the deposit. The presence of invisible gold within the löllingite, but not within the arsenopyrite, shows that gold is not incorporated into arsenopyrite at high temperatures and will instead be concentrated in the löllingite core of the composite grain and at the margin between the two sulfide phases as the löllingite is altered to arsenopyrite. Previous research on the Fäboliden gold deposit, including geothermometric analysis of vein-hosted graphite within fluid inclusions and garnet-biotite geothermometry as well as structural evidence provided by regional deformation, indicate that mineralization occurred post-peak metamorphism. The textures seen are therefore not conclusive of mineralization occurring syn- or pre-peak metamorphism, as has previously been proposed based on research of orogenic gold deposits in Western Australia. The spot analysis of pyrrhotite samples from across the deposit shows a distinct decrease in Ni and Co content in the proximal alteration zone, suggesting uptake of these elements by other minerals such as the löllingite and arsenopyrite. Multiple analyses performed on single grains show local variation, but are insufficient to establish the presence or determine the character of growth zonation within pyrrhotite.

The development of flexible lightweight OLED devices requires oxygen/moisture barrier layer thin films with water vapour transmission rates (WVTR) of < 10-6 g/m2/day. This thesis reports on single and multilayer architecture barrier layers (mostly based on SiO2, Al2O3 and TiO2) deposited onto glass, Si and polymeric substrates using remote plasma sputtering. The reactive sputtering depositions were performed on Plasma Quest S500 based sputter systems and the morphology, nanostructure and composition of the coatings have been examined using SEM, EDX, STEM, XPS, XRD and AFM. The WVTR has been determined using industry standard techniques (e.g. MOCON) but, for rapid screening of the deposited layers, an in-house permeation test was also developed. SEM, XRD and STEM results showed that the coatings exhibited a dense, amorphous structure with no evidence of columnar growth. However, all of the single and multilayer coatings exhibited relatively poor WVTRs of > 1 x 10-1 g/m2/day at 38 °C and 85 % RH. Further characterisation indicated that the barrier films were failing due to the presence of substrate asperities and airborne particulates. Different mechanisms were investigated in an attempt to reduce the density of film defects including incorporation of a getter layer, modification of growth kinetics, plasma treatment and polymer planarising, but none were successful in lowering the WVTR. Review of this issue indicated that the achievement of good barrier layers was likely to be problematic in commercial practice due to the cost implications of adequately reducing particulate density and the need to cover deliberately non-planar surfaces and fabricated 3D structures. Conformal coverage would therefore be required to bury surface structures and to mitigate particulate issues. Studies of the remote plasma system showed that it both inherently delivered an ionised physical vapour deposition (IPVD) process and was compatible with bias re-sputtering of substrates. Accordingly, a process using RF substrate bias to conformally coat surfaces was developed to encapsulate surface particulates and seal associated permeation paths. An order of magnitude improvement in WVTR (6.7 x 10-2 g/m2/day) was measured for initial Al2O3 coatings deposited with substrate bias. The development of substrate bias to enhance conformal coverage provides significant new commercial benefit. Furthermore, conformal coverage of 5:1 aspect ratio structures have been demonstrated by alternating the substrate bias between -222 V and -267 V, with a 50 % dwell time at each voltage. Further development and optimisation of the substrate bias technique is required to fully explore the potential for further improving barrier properties and conformal coverage of high aspect ratio and other 3D structures.

In this study, coatings of hydroxyapatite (HAp) prepared by thermal spraying technique are investigated for biological response. Spraying was done on two geometrically different Ti-6Al-4V alloy substrates under atmospheric conditions. Subsequent immersion experiments, mimicking physiological environment, were carried out using simulated body fluids (SBF). Non-destructive techniques utilizing conventional and high-energy synchrotron diffractometry were employed for depth–resolved investigations of phase composition, crystallinity and residual stresses within the coating for both substrate geometries. Microscopy techniques were used to examine surface morphology and microstructure. In both substrate geometries and for all immersion periods, HAp is the predominant phase with tetra-calcium phosphate (TTCP) and tri-calcium phosphate (TCP) the two main thermal products. The coating deposited on cylindrical rod substrate show a higher volume fraction of HAp at the near-surface region for the as-sprayed condition and samples immersed for 7 and 28 days. Further immersion shows the former decreasing gradually while the latter saturates after 28 days. Thermal products TTCP and TCP, for the coating deposited on the flat geometry substrate decreased with immersion, while those deposited on the cylindrical rod remains roughly the same before increasing slightly. Through-thickness behavior shows the as-sprayed HAp increasing almost linearly with depth, reaching a maximum around the coating midpoint before decreasing with further depth. Immersion in SBF does not alter the general trend across the coating however it increased the volume fraction of HAp within the first half of the coating with the biggest change occurring between 7 and 28-days of immersion. The variation of HAp with depth and immersion at the three lateral positions shows agreement within error bars indicating the coating to be homogenous. The trend is observed for coating deposited on cylindrical substrate geometry. Both substrate geometries show high near-surface region crystallinity with an index of ~90%. The interface region is less crystalline with a degree of crystallinity index of 67% and 56% for the flat and cylindrical substrates, respectively. Immersion in SBF does not alter the general through-thickness trend however it increased the degree of crystallinity at both ends. Residual stresses for the coating deposited on both substrate geometries are tensile and small, not exceeding 42 MPa and 65 MPa, respectively. The stresses are mainly confined in the near-surface region with the interior region showing neglible stresses, <10 MPa. Immersion in SBF relaxes the stress with the interior to almost zero. In the as-sprayed condition, the magnitudes of the average normal stresses 11 and 22 are 36.1 ± 2.9 MPa and 36.2  3.0 MPa, respectively; the stresses increase by ~10% and ~13% to 39.6 ± 2.6 MPa and 41.0 ± 2.6 MPa respectively upon immersion. With further immersion i.e. after 28 days, they relax and stabilize around 25.6 ± 2.8 MPa and 28.4 ± 2.8 MPa. Coatings deposited on cylindrical rod show similar trend with 11 and 22 increasing from 57.7 ± 3.2 MPa to 37.2 ± 3.1 MPa to 63.4  2.6 MPa and 41.9  3.5 MPa, respectively and subsequently decreasing 51.0 3.5 MPa and 39.3  3.3 MPa, respectively. Microscopy analysis of the coating show typical plasma sprayed coating morphology with glassy smooth regions, pancake splats, cracks as well as partial molten particles across coating surface. Immersion in SBF resulted in dissolution of ions from the coating hence increasing the surface roughness. Further immersion led to the formation of a precipitate layer which grew in thickness with immersion period. The precipitate extended deeper into the coating through a 3-D network of channels. Overall, the first 7 days of immersion are crucial with SBF-induced changes of the above-mentioned occurring during this period and the near-surface region being the most affected. Substrate geometry seems to have an effect on the crystallinity, phase composition, residual stress as well as their dissolution.
Thesis (PhD)--University of Pretoria, 2019.
Physics
PhD
Unrestricted

The structure and the energy band gap of hydrogenated amorphous silicon carbide are theoretically revised. In the light of defect pool model, density of states distribution is investigated for various regions of mobility gap. The films are deposited by plasma enhanced chemical vapor deposition system with various gas concentrations at two different, lower (30 mW/cm2) and higher (90 mW/cm2), radio frequency power densities. The elemental composition of hydrogenated amorphous silicon carbide films and relative composition of existing bond types are analyzed by x-ray photoelectron spectroscopy measurements. The thicknesses, deposition rates, refractive indices and optical band gaps of the films are determined by ultraviolet visible transmittance measurements. Uniformity of the deposited films is analyzed along the radial direction of the bottom electrode of the plasma enhanced chemical vapor deposition reactor. The molecular vibration characteristics of the films are reviewed and analyzed by Fourier transform infrared spectroscopy measurements. Electrical characteristics of the films are analyzed by dc conductivity measurements. Conduction mechanisms, such as extended state, nearest neighbor and variable range hopping in tail states are revised. The hopping conductivities are analyzed by considering the density of states distribution in various regions of mobility gap. The experimentally measured activation energies for the films of high carbon content are too low to be interpreted as the difference between Fermi level and relevant band edge. This anomaly has been successfully removed by introducing hopping conduction across localized tail states of the relevant band. In other words, the second contribution lowers the mobility edge towards the Fermi level.

Cette etude vise a une meilleure comprehension des decharges microonde (creees par ondes de surface) et radiofrequence, utilisees pour les depots a basse temperature de couches minces dielectriques. Elle permet de valider le concept de reacteur a double plasma pour les depots d'oxydes et de nitrures de silicium. Elle comporte deux aspects differents faisant appel a la physico-chimie des plasmas et a la science des materiaux. Une premiere partie est consacree a l'etude des plasmas (microonde et/ou radiofrequence) d'ar, d'o#2, d'ar-o#2 et d'ar-he-o#2 a deux positions differentes de la decharge. L'interferometrie microonde et la spectroscopie d'emission optique (techniques d'autoabsorption et d'actinometrie) sont utilisees pour determiner respectivement la densite electronique, la densite des metastables d'argon et la densite d'oxygenes atomiques. Une deuxieme partie est consacree d'une part a l'etude des conditions de depot, d'autre part a l'analyse des proprietes optiques, chimiques et structurelles des films deposes. Nous avons etudie l'influence de differents parametres comme la temperature de depot, la puissance microonde, les differents debits de gaz ou les differentes dilutions, ainsi que les effets de couplage des deux plasmas. Les couches minces deposees ont ete analysees par ellipsometrie uv-visible in situ, transmission infrarouge, mesures nucleaires (erda, rbs), edx et absorption dans l'uv lointain. Nous avons mis en evidence le role du bombardement ionique et le fait qu'il est possible de reduire la quantite d'hydrogene (sous forme de groupement o-h) contenu dans les films en les exposant a une illumination uv

Nanoscience and Nanotechnology have experienced a tremendous growth in few years. Nanotechnologies are the design, characterization, production and application of structures, devices and systems by controlling shape and size at nanometer scale. Carbon exists in several forms, depending on how the carbon atoms are arranged, their properties vary. One of the carbon forms is carbon nanotubes, which are capped at each end by half of a fullerene, and have aroused great interest in the research community because of their exotic electrical, thermal and mechanical properties. MWCNTs and SWCNTs were discovered in 1991 and 1993, respectively, by Ijima. A single-wall carbon nanotube can be described as a graphene sheet rolled into a cylindrical shape so that the structure has one-dimensional axial symmetry. Carbon nanotubes (CNTs) have unique characteristics that allow them to act as electrodes in charge storage devices, sensors and traps for pollutants, among others. On the one hand, for applications that require a certain amount of energy in pulse form, the traditional capacitors used in electronic circuits are not suitable because they cannot store enough energy in the volume and weight available. However, given the characteristics of CNTs that have a narrow size distribution, large specific surface area, low resistivity and high stability, CNTs have been regarded as a suitable material for electrodes in supercapacitors. On the other hand, the development of new systems, based in CNTs, which could overcome some of the current limitations in the capture of emerging pollutants in fluids, such as nanometric particles (being, moreover, difficult to detect) and organic pollutants at very low concentrations, is an additional objective of the present thesis. Water plasma and nitrogen plasma treatments were performed to remove amorphous carbon and to functionalize the surface of CNTs with different oxygen or nitrogen groups. Conditions of plasma treatments were optimized by adopting a Box-Wilson experimental design. Various microscopic and spectroscopic techniques were used to characterize the morphology, structure and elemental compositions before and after the plasma treatments. Electrochemical measurements show that water plasma treatment significantly increases the active surface area of CNTs, and nitrogen plasma is more effective to improve the charge transfer. Both nitrogen and water plasma raise the capacitance of CNTs notably in comparison to untreated CNTs. Manganese dioxide was deposited by galvanostatic method on untreated CNTs and plasma treated nanotubes. The MnO2 structure changes from nanoflower (as deposited) to needle like or to a layer coating on the surface of CNTs depending on the voltage applied during the cycling measurements. CNTs treated with 75 W plasma power and 10 Pa nitrogen pressure, and further functionalized with MnO2, exhibit the highest specific capacitance obtained in this thesis; 955 Fg-1 at 10 mVs-1. This value is almost 87% of the theoretical value for MnO2. The structural evolution of CNTs during water assisted growth has also been studied. The obtained length of CNTs was ~ 800 µm on silicon wafer. Transfer of ultralong CNTs on conductive adhesive aluminum tape was carried out using a novel methodology that lowers the series resistance of the electrode. The specific capacitance of CNTs/Al increases from 87 to 148 Fg-1 for untreated and water plasma treated CNTs/Al, respectively. In addition, we found that for a successful and faster growth of CNTs on copper substrate, strong adhesion of the buffer layer (Al2O3) is essential. A multilayered setup (Cu/Ni/Ti/Al2O3) prior to catalyst deposition boosts the growth rate and quality of CNTs. Vertically-aligned CNTs were synthesized on quartz fiber filters for environmental applications. Three chlorinated VOCs; trichloroethylene, chloroform and 1,2-dichlorobenzene were used to study the adsorption/desorption properties of CNTs/QF. The ability to detect or remove organic pollutants increases after the water plasma treatment, which functionalizes the CNTs surface and removes the catalyst from the top of CNTs (inner cavities are available for use). We found that molecules with aromatic rings present stronger interactions with CNTs (Phi-stacking).
La nanociencia y la nanotecnología han experimentado un enorme crecimiento en pocos años. Una de las formas del carbono son los nanotubos de carbono, que están limitados en cada extremo por medio fulereno, y que han despertado un gran interés en la comunidad científica debido a sus exóticas propiedades eléctricas, térmicas y mecánicas. Un nanotubo de carbono de pared simple puede ser descrito como una hoja de grafeno enrollada en forma cilíndrica de modo que la estructura tiene una simetría axial. Los nanotubos de carbono (CNTs) tienen características únicas que les permiten actuar como electrodos en dispositivos de almacenamiento de carga, sensores y adsorción de contaminantes, entre otros. Los principales objetivos de esta tesis son la síntesis de CNTs sobre los diversos sustratos para aplicaciones de almacenamiento de carga (supercondensadores) y ambientales. Tratamientos de plasma de agua y nitrógeno se realizaron para eliminar el carbono amorfo y funcionalizar la superficie de los CNTs con diferentes grupos de oxígeno o nitrógeno. Las condiciones de los tratamientos de plasma fueron optimizados mediante la utilización de un diseño experimental de Box-Wilson. Las medidas electroquímicas muestran que el tratamiento con plasma de agua aumenta significativamente el área superficial activa de los CNTs, y el plasma de nitrógeno es más eficaz para mejorar la transferencia de carga. Tanto el plasma de nitrógeno como el de agua aumentan la capacidad de los nanotubos de carbono en comparación con los CNTs no tratados. El dióxido de manganeso se depositó electroquímicamente mediante el método galvanostático sobre los nanotubos de carbono sin tratar y tratados con plasma. La estructura de MnO2 cambia de una estructura de “nanoflor” (inicialmente) a una en forma tipo aguja o de capa superficial en función del voltaje aplicado durante los experimentos de ciclado. Los CNTs tratados con 75 W de potencia de plasma y 10 Pa de presión de nitrógeno, y posteriormente funcionalizados con MnO2, exhiben la capacitancia específica más alta obtenida en esta tesis; 955 Fg-1 a 10 mVs-1. Este valor es aproximadamente el 87% del valor teórico para MnO2. La evolución estructural de los nanotubos de carbono durante su crecimiento asistido por agua ha sido estudiada. La longitud obtenida de los CNTs es de ~ 800 micras sobre una oblea de silicio. La transferencia de CNTs ultralargos a una cinta adhesiva de aluminio conductor se llevó a cabo utilizando una metodología novedosa que reduce la resistencia en serie del electrodo. La capacidad específica de los CNTs / Al aumenta de 87 a 148 Fg-1 para los CNTs / Al sin y con tratamiento de plasma de agua, respectivamente. Una configuración de múltiples capas (Cu/Ni/Ti/Al2O3) antes de depositar el catalizador aumenta la velocidad de crecimiento y la calidad de los CNTs. CNTs verticalmente alineados se sintetizaron sobre filtros de fibra de cuarzo para aplicaciones ambientales. Tres compuestos orgánicos volátiles clorados; tricloroetileno, cloroformo y 1,2 diclorobenceno se utilizaron para estudiar las propiedades de adsorción / desorción de CNTs / QF. Se vio que las moléculas con anillos aromáticos presentan interacciones más fuertes con los nanotubos de carbono (apilamiento de tipo pi).

碩士
國立成功大學
材料科學(工程)研究所
82
TiN 鍍層是目前耐磨耗鍍層材料中使用相當成功的一個範例，而後來新發 展的TiAlN 鍍層與TiN 鍍層比較有如下之優點:(1)可抵抗高溫氧化至800 ℃,TiN只有550℃(2)較佳的耐磨耗性(尤其是難加工材料)(3)較低的熱傳 導係數(TiAlN:16,TiN:19w/mK(4)較好的附著性(Scratch test ;Lc: TiAlN=80.3N,TiN=60.3N)。所以在目前工業上，TiAlN 鍍層已漸漸取代 TiN 鍍層，成為刀、模具使用的新耐磨耗鍍層，尤其是對於高速切削的應 用。唯其影響耐磨耗性差異的原因錯綜複雜很難有定論，本研究擬嘗試著 探討它。本研究首先是擬探討以Arc Evaporation 技術，於工具鋼上蒸鍍 Ti AlN 鍍層之最佳蒸鍍條件，再以田口式實驗設計法(L-18)，所歸納出 影響TiAlN 鍍層耐磨耗性的兩個最主要實驗變數:(1)基板偏壓(2) 氮氣分 壓，來進行主要變數實驗(Ti/Al=50/50及72/28各七組)探討TiAlN 鍍層的 耐磨耗性質。而鍍層磨耗測試是使用FALEX-6 磨耗試驗機與S45C碳鋼對磨 方式進行鍍層磨耗測試。於其中選出耐磨耗性不一的六組試件(Ti/ Al=50/50 No.4,2,5;Ti/Al=72/28 No.12,8,9)，經由XRD相分析、EDS成份 分析、表面粗糙度量測、SEM表面形態觀察及微結構晶粒觀察、AUGER縱深 分析、Mapping 元素分析，以探討TiAlN鍍層耐磨耗性差異之所在。實驗 結果顯示: 靶材成份為Ti/Al=50/50 者結晶相中B1-phase(111)面成長越 不顯著，耐磨耗性越佳；Ti/Al=72/28靶材所鍍鍍層之耐磨耗性則無明顯 變化；同一成份之鍍層中Ti 含量越高，耐磨耗性亦越佳；鍍層表面形態 及粗糙度對耐磨耗性並無顯著性影響； 微結構的晶粒趨向柱狀晶或等軸 晶的鍍層，有較好的耐磨耗性； 鍍層微結構的晶粒趨向纖維狀，則耐磨 耗性較差；耐磨耗性較佳之鍍層經磨耗之後， 鐵屑易殘留附著於磨耗區 ；磨耗區所附著之鐵元素有固體潤滑作用； 本實驗之磨耗形態屬於黏附 磨耗。

碩士
龍華科技大學
工程技術研究所
97
In this study, a unique fabrication technique, with combination of hot-wall low pressure chemical vapor deposition (LPCVD), sputtering of buffer layers, and RF plasma surface treatment experiment, was developed and used to produce zinc oxide films with outstanding optronic properties. Three sets of experiments were performed; solely CVD, plasma treatment of substrates before CVD, or treatment of deposited layers after CVD. Fluorescence spectroscopy (PL), X-ray diffractometry (XRD), atomic force microscope (AFM), and scanning electron microscopy (SEM) were used to analyze samples. The PL analysis results show that, as compared with solely CVD, surface modification after CVD has been confirmed to be a very effective way to improve the near band edge emission PL line near 380 nm. Some post CVD treated samples have PL peak intensity 30 times stronger than samples with no treatment. Actually, for almost all samples, with the oxygen concentration in CVD chamber from 10% to 90%, it was found out that plasma modification may increase the PL peak intensity for several orders of magnitude. For all plasma treated CVD samples tested, samples deposited with an oxygen content of 70% give the best results. On the other hand, XRD analysis shows these samples are nearly all (002) preferential oriented ZnO poly-crystals. For samples with treatment after CVD, the XRD peak intensity reduces, seemingly due to sputtering effect from Ar ions in plasma. SEM images show that, after treatment, the grain size of CVD ZnO solid remains unchanged, but the density decreases. No significant effect was observed on the grain size and shape. AFM shows, after treatment, surface roughness are reduced, giving a more flat surface. As regarding to PL studies for semiconductor materials, since the photon escape depth is limited, PL has been regarded as surface phenomena. However, the effective region for plasma treatment is also just only a few nm thick. It was proposed that this is the reason why plasma treated CVD films can achieve better light-emitting PL efficiency.

碩士
中原大學
化學工程學系
85
In order to improve the membrane's oxygen selectivity, ethylenediamine was deposited on a polybutadiene/porous polycarbonate (PB/PC) composite membrane and a polyurethane (PU) membrane. The latter was further immered in a Cobalt salt solution to form a cobalt complex. Plasma treatment result in physical and chemical change on the surface of PB/PC composite membrane. To study the chemical effect, a PB/PC composite membrane was modified chemically by ethylenediamine, compared with the composite membrane treated with nonreactive plasma, at the same N2 flux, the former owned a higher oxygen selectivity(α=5.7). It was obvious that the grafted ethylenediamine enhance the oxygen selectivity. Then, the PB/PC composite membrane was modified by ethylenediamine plasma treatment, as the plasma power increased, the selectivity increased by a sacrifice of permeability. We also found that the 70w plasma treated membrane(α=10.5, P/l=0.07GPU) owned both higher selectivity and permeability than the 50w one(a=8.9, P/l=0.04GPU). We recognized that it was the competition of etching and grafting effect on the surface of PB/PC membrane. From the SEM analysis, the top layer thickness of 70w plasma treated membrane was half of the 50w one. From the ESCA analysis, N/C ratio of 70w plasma treated membrane was higher than the 50w one. It was indicated that a high nitrogen containing thin top layer of the 70w plasma treated membrane was responsible for the higher oxygen selectivity and permeability. The PU membrane was modified by ethylenediamine plasma treatment, the selectivity increased from 2.6 to 3.1 but the permeability decreased from 35 barrer to 15 barrer. The selectivity was further improved to 4.4 by immersing the plasma treated membrane in a solution of CoCl2.6H2O/Formamide for 1 hr, but the permeability decreased to 9 barrer. We also found that as the immersing time increased the permeability could be greatly increased by slightly sacrificing the selectivity. This is the result of swelling effect of the PU membrane caused by Formamide solution.

碩士
國立交通大學
電子工程系
89
To reduce the probability of moisture uptake and to strength the adhesion between MSQ/liner-LPD and copper, the improvement of liner LPD-SiO2 deposited on MSQ is studied. In this work, to make LPD-SiO2 deposited on MSQ film, we adopted H2 plasma treatment on MSQ. In addition, H2 plasma treatment can improve MSQ leakage current but dielectric constant invariant. Although LPD deposition after H2 plasma can make leakage current slightly increase, however the increase can be reduced if the time of plasma treatment is long enough. Besides, LPD-SiO2 incubation time also increases as H2 plasma treatment time increases. However the deposition rate is almost independent of plasma treatment. We have proposed a model to explain the phenomenon about incubation time according to the results of SIMS spectra and LPD deposition-rate graph. Conclusively, 10min H2 plasma is the best condition in this work. To further improve the performance of LPD-SiO2 with N2O plasma, at the first time, we investigated two-steps N2O plasma. From the C-V curves, we obviously found that the flat-band voltage of these samples shifts to either left or right. And we have tried to introduce two mechanisms about the flat-band voltage shift. However, the amount of left-shift for the first mechanism is larger than that of right-shift for the second. From the leakage current (J-E) curves, we found the better improvement of LPD-SiO2 with two-steps N2O plasma. Nitrogen incorporation at Si/LPD-SiO2 interface and reoxidation reaction can make leakage current decrease. As the thickness of LPD-SiO2 in the first-step N2O plasma decreases, the leakage current density obviously decreases. In addition, to deposit high quality LPD oxide film, we adopted new SiO2 powder & new H2SiF6 liquids with less impurity. Under the condition of new H2SiF6 liquids, the leakage current density of LPD-SiO2 prepared with new SiO2 powder at E=2MV/cm is 2x10-9 A/cm2, and approximately two orders lower than that with old SiO2 powder. The breakdown field is also slightly high. The uniformity of deposition thickness is about ~2%, and the dielectric constant value is ~3.3.

碩士
元智大學
機械工程學系
94
In this Thesis , we focus on this microwave plasma chemical vapor deposit system which research and develop diamond membrane and nanotubes experiment . First , we try to use microchip and some hardware to carry the goal which is remote control . Second , we compare all kind of the ways of operate between control law and human’s experience , and we can believe that contol law is better than human experience . This thesis proposes that a kind of control method " searching method ", tests and can know via the experiment can get more rapidly , accurately and reflect the result lower in power by using control method to adjust the reflect of power . Make use of and improve this systematic reappearing , success rate and dependability varying the parameter in the course of experiment with this result .

碩士
國立中央大學
光機電工程研究所
105
In recent years there have been many research of surface hydrophobicity characteristics, in which there is a surface of extreme wet behavior known as super-hydrophilic properties. When the water droplets on the super-hydrophilic surface, the water contact angle is less than 10 °. On this surface is conducive to rapid spread of water so that it has a fast drying of the excellent performance, so super-hydrophilic surface with rapid evaporation cooling, Anti-fog and other functions. In this research organic silane was used as the process reaction gas, finally organic silane Superhydrophilic thin film deposited on the substrate by plasma polymerization. By changing the process parameters, such as anode voltage, deposition time, etc., making the organic silane plasma polymer film with super-hydrophilic properties, using optical emission spectrometer for dynamic observation in the process. In the case of lifting the anode voltage, the increase in CN signal strength indicates that the nitrogen content of the thin film is increased. The water contact angle is less than 10 ° with super-hydrophilic characteristic measured by the water contact angle. Analysis of membrane element composition ratio by XPS, the results show that the highest N / Si ratio under the high anode voltage parameters indicates that the surface has the most nitrogen-containing functional groups. This functional group is the main reason for the super-hydrophilic properties of organic silane plasma polymer films. Optical properties, the average visible light transmittance of glass substrates are greater than 90.4%, PC plastic substrates are greater than 88.9%, with good optical properties.

博士
國立成功大學
化學工程學系碩博士班
100
Diamond-like carbon (DLC) nanocomposite films containing nanostructures were synthesized by various deposition techniques, including inductively-coupled plasma chemical vapor deposition (ICP-CVD), sputtering-assisted CVD, capacitive-coupled plasma CVD, plasma jet CVD etc. By incorporating high densities of ceramic nanoparticles (SiC, Si3N4, ZrO2, TiC, TiO2, ZnO, etc.) and nano-carbons, DLC nanocomposites can present the increase of film hardness and the reduction of film stress, as well as the enhancement of toughness, increase of film adhesion, and decrease of friction coefficients with novel function of light-induced hydrophilicity. SiCxNy nanocrystallites-containing DLC nanocomposite films were prepared by ICP-CVD using a hexamethyldisilazane (HMDSN) precursor. The substrate was biased by a pulsed-DC power supply to provide the necessary energy of deposited ions. The effects of substrate bias on the surface morphology, roughness, and the mechanical properties of nanocomposite film were well investigated. The results revealed the film has maximum hardness of 15 GPa at a relative low stress of 0.5 GPa at an ICP power of 100W, and a substrate bias of -200V. The films exhibited a lower coefficient of friction in the range of 0.06 to 0.09 via nano-scratch technique, and had lower wear depth with a good wear performance using nano-wear test. The fracture toughness of the film was greatly enhanced by the incorporation of SiCxNy nanoparticles in the DLC matrix, measured from its resistance to crack propagation by the indentation method of Vickers indenter. Zirconia-containing DLC nanocomposite films were prepared by sputtering-assisted plasma CVD. ZrO2-DLC films were deposited using acetylene as the carbon source, and argon was used to sputter ZrO2 target. AFM results show that the surface of the films is very smooth. The tribological properties of the films could be controlled by adjusting the substrate biases during depositions. A higher energy of ion bombardment in this system biasing by pulsed-DC, induces the formation of sp2 carbon bonding in the film and makes the films’ hardness and Young’s modulus drop. The fractured toughness of DLC nanocomposite films measured by Vickers indenter were in the range from 14 to 22 MPa•m1/2, revealing the enhancement of film toughness. Nano-carbons embedded in DLC nanocomposite films were synthesized by plasma jet CVD in the mixed gases of benzene and nitrogen. Transmission electron microscopy images of the films indicate the existence of nanostructured carbon. A high degree of dissociation and reaction in plasma jet reactor and appropriate nitrogen contents in the gas phase are important for the growth of nanostructured carbon embedded in the DLC matrix. Synthesis of TiO2-DLC nanocomposite films with novel functions were studied by sputtering-assisted plasma CVD. With titanium-oxygen species sputtered from titania (TiO2) target by argon using a radio-frequency (RF) power, DLC films were simultaneously grown on the negatively-biased substrate by plasma CVD of acetylene gas using a pulsed direct-current (DC) power. By adjusting the sputtering power, both TiO2 and TiC nanoparticles could be incorporated in the DLC films. The TiO2-DLC nanocomposite films deposited at 80.7 % Ar exhibited a high hardness of around 14 GPa at a relatively low stress and, particularly, a fast rate of turning super-hydrophilic by reaching zero degree of water contact angle under 40 minutes of ultraviolet irradiation. Synthesis of amorphous boron nitride films (a-BN) at low temperature were studied by hollow cathode discharge CVD. Borazine and N2 gases were employed as the precursors to deposit a-BN films. The as-deposited films were amorphous phase with a transparent and smooth surface. Fourier transform infrared spectroscopy (FTIR) revealed that with a high nitrogen concentration and a high hollow cathode power, high content of sp3-bonded BN can be obtained. Hollow cathode plasma was essential in forming the sp3-bonded BN in the film.

碩士
逢甲大學
材料科學研究所
84
Recent investigation on the current status of hard coatings shows that cathodic arc plasma (CAP) deposition is the most widely used process for tool application while titanium nitride (TiN) is the most common material.Great advantages can be obtained from CAP coating that plenty of reports about wear behavior were appeared. However, these reports emphasized the performance of tool materials with and without CAP coating. A systematical study on the coating parameters that affecting the wear behavior is lake. In this study, wear test were carried out by using Ball-on- Disk sliding wear test which is the closest method to real metal forming. Substrate bias and nitrogen pressure, which are the most important coating parameters for arc-evaporation, and the substrate bias during the initial etching stage ( titanium ion bombardment ) were changed to evaluate the influence on wear performance. Experimental results showed that the amounts and sizes of macroparticles, film thickness, hardness, adhesion and microstructure of TiN film were all affected by coating parameters. The deposited films were observed with a decrease in the amount and size of macroparticles, deposition rate, hardness and adhesion when increasing substrate bias. With increasing substrate bias the TiN(111) preferred orientation was replaced by TiN(220). A decrease in the amount of macroparticles and voids with increasing nitrogen pressure, while the deposition rate and adhesion increased, the preferred orientation changed to TiN(111). During the etching stage, the higher substrate bias suffered a higher ion flux and the subsequent higher substrate temperature, which flattened the macroparticles in the deposited film and the higher adhesion strength. The wear test showed that TiN films whatever deposited exhibited a low wear loss.Some appeared a negative values. The films deposited at low substrate bias with higher density in macroparticles caused a mass transfer of the counter material and the negative value in wear loss was obtained. The higher friction coefficient of the TiN film obtained at high substrate bias was dominantly attributed to the contribution of gouging wear. The wear modes observed were abrasion wear, gouging wear, brinelling and adhesive wear in mass transfer mode.The decreased friction coefficient with increasing nitrogen pressure should then be attributed to a decreased amount of macroparticles on the surface of deposited films and wear loss gradually changed to a negative value,owing to mass transfer. The wear modes observed were composed of abrasion wear of the counter material against the deposited films and substrate, gouging wear, the spalling of deposited films and adhesive wear in mass transfer mode.

碩士
大同工學院
材料工程研究所
87
Plasma contains activated species able to initiate chemical and physical reactions at solid surface. The organic gas plasma deposition leads to polymer-forming reactions. The water-soluble polymeric chains can be readily induced on the surface of plasma polymerized deposited films by photo-induced graft polymerization. In this study, graft polymerization of acrylamide (AAm) was used to modify the surface of inorganic materials, which were pre-treated with plasma polymerization. The surface modifications of the polymers both by plasma CVD and by the subsequent UV photo-induced graft polymerization of AAm were evaluated. The results were summarized as on the followings: 1. The effect of graft AAm on humidity sensing properties A resistive type sensor device was made by semi-conductor manufacture technology on the Si wafer. Plasma-polymerized organic film with semi-conductive SnOx was used as a sensitive layer with peroxide and radical. This film is fabricated by duplex process; (1) photo-initiated surface graft polymerized hydrophilic acrylamide (AAm); (2)immobilization of water soluble polymer solution such as PAAm by γ-ray irradiation. By surface modification of plasma deposited films, transition from hydrophobic to hydrophilic has been achieved to improve humidity sensibility in sensor application. After grafting hydrophilic copolymer, the humidity sense range will increase from R.H. 45~65 % to R.H. 45~85 %, while the response time will decrease to about 3 sec. 2. The interlayer between the inorganic substrate and enzyme The structures of metals and ceramics are distinct from the polymers. In general, it is difficult to combine polymer with metals and ceramics. Plasma deposited films have good adhesion with substrates, and some radicals and peroxides are generated on it. After grafting Acrylamide (AAm) polymerization, functional structure that suitable for chemical bond proteins on surface can be formed on the surface. Therefore, the enzyme can be immobilized on the surface of an inorganic substrate convalently. However, in the process of enzyme immobilization, the amount of —NH2 group on the grafting AAm surface is not enough for GA bonding with the —NH2 group of enzyme. In this study, before GA reaction we introduced a pre-treatment on the surface to increase the amide groups by PEI (polyethylene-imine, (C2H5N)n)) treatment on the surface. An amide bond is formed between the amino group of PEI and grafted-AAm surface. Thus, the enzymes were effectively covalent bonding between GA treated surface. The Glucose oxidase (GOD) enzyme was used to immobilize on the inorganic materials surface, which was treated by duplex process, i.e., the plasma polymerized organo-tin films and subsequent surface-graft AAm with glutaraldehyde (GA) as a linking agent. The activity of immoilized GOD on the sample with PEI pre-treatment increase about 15~20 times higher than that without PEI pre-treatment. Therefore the PEI pre-treatment could improve the immobilized amount of GOD on inorganic materials.

碩士
中原大學
化學工程學系
85
2,3-(epoxypropyl)-methacrylate (EPMA) was graft-polymerized onto a crosslinked polyurethane (CPU) membrane which had been pretreated by glow discharge plasma. The EPMA-g-CPU membrane was applied to the pervaporation process for removing water from a ethanol aqueous solution. In this study, the effects of the plasma power, plasma treatment time, and grafted polymerization time on the graft yield and pervaporation performance were investigated. The effects of the operating conditions of plasma treatment on the structure of EPMA-g-CPU membranes were examined by FTIR, ESCA, Contact Angle, and SEM. It was found that the graft yield first reached a maximum value and then fell down as the plasma power, and treatment time increased. The appearance of a maximum was due to the competition of plasma etching and grafting. An EPMA-g-CPU membrane was found to have a separation factor of 97, and a permeation rate of 240g/m(2)h at 25℃ when the feed concentration was 90wt% water-ethanol solution. This specific membrane had a graft yield of 4.81mg/cm(2) and was obtained by glow discharging for 120sec at 10W and grafting polymerization for 2h at 60 ℃. The EPMA-g-CPU (graft yield 4.81mg/cm(2)) membranes were reacted with ethyleriediamine (EDA), diethylamine (DEA), H2SO4, or NaHSO3-NazSO3. The pervaporation performances of the reacted membranes were discussed. It was found that the permeation rates of the reacted membranes-wereall higher than that of the unreacted one.

碩士
國立中央大學
光電科學與工程學系
103
The large stress causes films cracking or wrinkling and resulted the thin films peeling, so that reduced the yield and stability of the optical thin films production. Therefore, how to coat flexible polymeric films effectively and reduce the stress of multilayer optical films is the aim in this study. In this study, HMDSO monomer was lysed by plasma polymerization, and then the plasma polymer films was coated. The composition structure, optical properties, proportion of elements and films stress of the coated polymer films were investigated by changing the flow of HMDSO, the flow of oxygen, beam current and anode voltage. The average transmittance of the deposited films is above 90%. When the Linear/Cage ratio decreases, the stress decreases from GPa to GPa. It proved that we can control the Linear/Cage ratio effectively and predicted the plasma polymer films stress by changing parameters. Finally, the multilayers were coated on the precoated polymer film shown that the stress of the multilayers was reduced 70 % effectively.

Thesis (Ph. D.)--University of Alberta, 2010.
Title from pdf file main screen (viewed on July 8, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Materials Engineering, Department of Chemical and Materials Engineering, University of Alberta. Includes bibliographical references.

碩士
國立成功大學
化學工程學系
102
The C60 incorporated diamond-like carbon films with low wear as well as high hardness were deposited on high temperature Si(100) substrate by RF-plasma-assisted chemical vapor deposition under different C60 content in acetylene. The lowest wear rate was achieved by 87.77 (10^-7mm3/mN) with 26.48 GPa in hardness. Incorporation of C60 into DLC decreases hardness, however decreases wear rate as well as friction coefficient within a range of suitable C60 content; beyond this range, over content of C60 endows DLC with high roughness therefore increases wear rate as well as friction coefficient.

碩士
龍華科技大學
工程技術研究所
101
In this study, the microwave plasma nitriding method will be carried out for the aluminum nitride surface treatment way to explore the formation and research. Research methods to change process parameters include base temperature, reaction gas ratio,microwave power to microwave plasma nitriding treatment. Analysis results base temperature 550℃, reaction gas ratio N2:H2=50:150sccm, microwave power 1000W to better nitridation reaction Finally, In this study, the best parameters are: microwave power 1000W, Reaction gas N2:H2=50:150sccm and base temperature 550℃to microwave plasma nitriding treatment, nitrided aluminum plate specimen analysis,the results showed that nitrogen ratio can be as high as 23.38% and a thickness of 15μm.

碩士
元智大學
化學工程與材料科學學系
97
In this study, atmospheric pressure plasma chemical vapor deposition (APPCVD) technique was employed to deposit SiOx thin film on Polycarbonate (PC) substrates. We anticipate improving the surface properties of plastic substrates. Hexamethyldisilazane (HMDSN) and Hexamethyldisiloxane (HMDSO) were utilized as the precursor for APPCVD. Atmospheric pressure plasma deposited SiOx thin films have been analyzed by the optical thin-film thickness detector, FTIR, XPS, AFM, and UV-VIS. With various operational parameters including in RF plasma power level, the distance of nozzle to substrate, oxygen gas flow rate, APP deposited SiOx thin films have been investigated for the change of surface properties and chemical composition. Moreover, Optical Emission Spectrometry (OES) was used for analysis the luminous gas phase of APPCVD process. The experimental results determined that the oxygen gas flow rate is the key point of APPCVD process. Depending on the proper operational parameters, SiOx thin film has excellent inorganic features. The hardness of atmospheric pressure plasma deposited PC substrates was improved from 6B to H, and obtains a transmission of 93 % in the visible region. Atmospheric pressure plasma surface modification technique was employed to improve adhesion between SiOx thin film and PC substrate. After atmospheric pressure plasma surface modification, the adhesion of plasma modified PC substrate is improved from 0B (percent area removed＞65 %) to 5B (none area removed).

碩士
國立成功大學
化學工程學系碩博士班
90
Diamond-like carbon (DLC) films are commonly used in industry because its high hardness, resistivity, and heat conductivity, good for wear, abrasion, chemical oxidation, and erosion. However, its application for both high hardness and electrical conductivity is few. In this study, we use capacitive RF plasma to deposit DLC films by benzene and acetylene, and add nitrogen gas at high temperature. The prepared DLC film shows high hardness and good conductivity. It could reach resistivity of 54 W-cm and hardness of 18.1 GPa in the case. We discussed the effects of nitrogen on conductivity and hardness of DLC. Increasing nitrogen concentration decreases its resistivity and hardness. It’s resistivity decreases fast initially, and than slowing down. We expressed the reason by IR analysis. The appearance of N-H bond shows the reason is caused by the termination of dangling bonds by hydrogen. Raman analysis showed the ratio of sp2/sp3 is increasing by nitrogen concentration, and its conductivity increased. Graphitization and formation of CºN bonds decrease the cross-linking of DLC, and hardness decreases. We found graphitic structure as carbon onion-like in DLC films using benzene as carbon sources. We found graphitic structure at low depositing temperature using TEM analysis. We thought that the ring structure of benzene supplied the mechanism of forming graphitic structure. It’s not easy to become such structure using acetylene as carbon source. Hydrogen concentration is influenced by high self-bias. The intensity of photoluminescence is caused by hydrogen, and we measured the slope of Raman spectrum to discuss the effect of self-bias to hydrogen content. TEM analysis found no graphitic structure in DLC films at low depositing self-bias. And we proposed the key factors of forming graphitic structure were benzene its self and high self-bias.

碩士
國立高雄應用科技大學
化學工程與材料工程系博碩士班
106
In this study, nickel oxide (NiO) thin films were deposited on glass substrate at temperature of 250℃and 300℃ by a homemade low temperature atmospheic pressure plasma system. The axial gas flow rate of 50 sccm to 200 sccm are used in this study. No diffraction peak was observed at 250℃ by the x-ray diffraction analysis. Nither the formation of particles nor thin films could not be found on the surface by a FE-SEM, which might be due to the insufficient thermal energy of the substrate. When the substrate temperature was 300℃ and the axial flow rate of 50 sccm, the NiO thin films were not formed. However, the NiO thin films were formed at the axial flow rate of 100 sccm to 200 sccm, which is confirmed by x-ray diffraction patterns (JCPDS #47-1049). The transmittance of the NiO thin films was 48% (100 sccm), 38% (150 sccm) and 35% (200 sccm) in the visible region. The best condition for the formation of the NiO thin films was the axial flow rate of 100 sccm at 300℃. The NiO thin films had P-type characteristics by a hot-probe method. The resistivity, electrical conductivity, carrier concentration, and mobility of the NiO thin films are measured by a Hall effect.

碩士
中原大學
電子工程研究所
99
Radio frequency plasma enhanced atomic layer deposition (RF-PEALD) technique was used to deposit nitrogen-doped (N-doped) p-type ZnO thin films on sapphire substrate at 75 - 250oC with an RF power of plasma source 0 - 200 W and NH3 flow rate of 5 – 50 sccm. Ammonia (NH3) gas, decomposed by the plasma to form N, NH and NH2, was used as the source of nitrogen and the flow rate of it was varied. The N-doped ZnO was deposited on sapphire substrate, and the thickness of 110 nm. Post-annealing treatment was conducted to remove the hydrogen ions in the as-grown films at 800oC to 900oC by a rapid thermal annealing (RTA) system. N-doped ZnO films were characterized by Hall measurements, X-ray diffraction (XRD), low temperature photoluminescence (LTPL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Hall measurements showed the highest hole concentration of 4.041017 cm-3, the lowest resistivity of 52.10 -cm, and the hole mobility of 0.55 cm2/V-s for N-doped ZnO, which was fabricated at 100oC substrate temperature 、with RF power of 100W and NH3 flow rate of 10sccm. Besides, the crystallographic structures and bonding configurations obtained from the XRD results demonstrated the formation of No acceptors by substituting N atom for O sublattice or N2 for O atom. The LTPL spectra for N-doped p-type ZnO films exhibited the emissions ascribed to the neutral donor bound excitons (DoX) at 3.361 eV, free electrons to acceptor (FA) transition at 3.311 eV, and the donor-acceptor pair (DAP) recombination at 3.255 eV with a weaker peak at 3.180 eV assigned to the longitudinal optical (LO) phonons. The appearance of both FA and DAP transitions related emissions are suggested to be associated with the replacement of N atom for O atom (No) in ZnO. XPS results indicated that a part of N substrate O atom to form the accepter-like defects. The binding energy of No could be established at 397.5 eV.

碩士
國立交通大學
材料科學與工程學系所
102
Flexible organic light emitting diode (FOLED) is an emerging technology of next-generation display and lighting for its excellent form factor and mobility. However, FLOED suffers a shortcoming that the oxygen and water permeating through plastic substrate at a relatively high rate, can react with the cathode, resulting in severe degradation. Therefore, high WVTR (water vapor transmission rate) performance barrier films with high transmittance and 10,000-hr lifetime are required for FLOED application. In this thesis, a multi-layered structure of SiCxNy/PPMMA (plasma polymerized methyl methacrylate) deposited on flexible PET substrate by PECVD at low temperature has been successfully developed to passivate OLED devices from moisture. In specific, two different precursors, N-Methyl-Aza-2,2,4- trimethylsilacyclopentane (MTSCP) and 1,3,5-trimethyl-1,3,5-trivinylcyclo- trisilazane (VSZ) were used for the deposition of SiCxNy film, while methyl methacrylate and styrene monomer were used as the precursor for PPMMA and plasma-polymerized polystyrene (PPS) films, respectively. The correlation between WVTR and the pinhole density of SiCxNy films using two different precursors were examined. It was found that MTSCP-derived SiCxNy film possessed better barrier effectiveness, i.e. WVTR because of its lower pinhole density compared to VSZ-derived film. Moreover, the WVTR of organic layer, PPMMA film was better than PPS film, due to its higher film density and small moisture solubility. The effect of inorganic/organic layer pairs was further studied to understand their contributions in the lag-time and WVTR. It was found that one additional pair of SiCxNy/PPMMA layers can extend the lag-time by 20% and reduce WVTR significantly within lag-time region, but has less effect in steady-state WVTR region. Three pairs of SiCxNy/PPMMA can reduce WVTR down to 9×10-4 g/m2/day, with a lag-time of 13 hours. The four-pair SiCxNy/PPMMA barrier stack on PET with an estimated WVTR of 5×10-4 g/m2/day was used to passivate an OLED lighting device. At an initial luminance of 4000 cd/m2, the operational half-lifetime was 93.3 hrs and an estimated lifetime of 3200 hrs (133days) at 500 cd/m2 was calculated, which was 70% longer than bare PET passivation.