Submitted by GILSON PIQUERAS GARCIA null (gilson.piqueras@gmail.com) on 2018-03-13T17:35:56Z No. of bitstreams: 1 Garcia, Gilson Piqueras. Efeito do tratamento de polímeros em plasmas de nitrogênio 2018. Tese (Doutorado).pdf: 3148171 bytes, checksum: 4ca44c01e1ec375c08f9b89261de68f3 (MD5) / Approved for entry into archive by Lucimara Kurokawa Shinoda null (lucimaraks@sorocaba.unesp.br) on 2018-03-14T17:38:12Z (GMT) No. of bitstreams: 1 garcia_gp_dr_soro.pdf: 3148171 bytes, checksum: 4ca44c01e1ec375c08f9b89261de68f3 (MD5) / Made available in DSpace on 2018-03-14T17:38:12Z (GMT). No. of bitstreams: 1 garcia_gp_dr_soro.pdf: 3148171 bytes, checksum: 4ca44c01e1ec375c08f9b89261de68f3 (MD5) Previous issue date: 2018-02-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O politetrafluoretileno (PTFE) e a poliamida 6 (PA 6) são polímeros que têm excelentes qualidades mecânicas, elétricas e químicas. Por isto, são utilizados em diversos componentes de equipamentos mecânicos e elétricos entre várias outras aplicações. Entretanto o PTFE possui um ângulo de contato com a água (WCA) de cerca de 120º e a PA 6 um WCA de cerca de 60º. Isto, especialmente no caso do PTFE, diminui a sua adesividade com outros materiais. Para resolver este problema várias técnicas têm sido sugeridas, como, por exemplo, tratamentos químicos e tratamento a plasma. Entre elas o tratamento a plasma, que tem a vantagem de produzir modificações apenas na superfície, não alterando o interior do material. O objetivo deste trabalho é estudar como o WCA varia em função dos parâmetros do tratamento a plasma de nitrogênio, a pressão do gás (p), a potência (P) e o tempo de tratamento (t). O nitrogênio foi escolhido por ser um gás cujo plasma, segundo a literatura, causa reduções significativas no ângulo de contato da superfície de polímeros. Várias séries de tratamento foram conduzidas, tanto para o PTFE quanto para a PA 6. Foram obtidas reduções significativas no WCA, ocorrendo o resultado notável de WCA = 0º para p = 2,6 Pa, P = 300 W e t = 30 min, tanto para o PTFE quanto para a PA 6. Em função dos resultados, dentro do intervalo de parâmetros utilizado, concluiu-se que, de uma forma geral, o WCA diminui com a potência e com o tempo de tratamento, e que o WCA tem um comportamento notável em função da pressão do gás, diminuindo inicialmente até atingir o valor mínimo (ótimo) de 0º para p = 2,6 Pa, e então passa a crescer a partir deste ponto. A redução do WCA das amostras tratadas foi consequência do aumento da energia de superfície, motivado pela incorporação de funções nitrogenadas e oxigenadas nas suas superfícies. A Espectroscopia de fotoelétrons excitados por raios X (XPS) foi usada para caracterizar a composição e estrutura da superfície do PTFE e da PA 6. A rugosidade e o ângulo de contato dos polímeros foram medidos por perfilometria e goniometria, respectivamente. A análise XPS mostrou, para o PTFE, que houve incorporação de oxigênio e nitrogênio, para a PA 6, o aumento da concentração de oxigênio, e para ambos, a presença de grupos químicos polares em sua superfície. As medições do WCA em função do tempo decorrido após o de tratamento, mostraram que, para o PTFE e para a PA 6, o WCA volta a crescer, estabilizando em torno de 90 dias, quando, para o PTFE atinge cerca de 80% do WCA da amostra sem tratamento. A PA 6 apresentou um resultado notável, com o WCA estabilizando com um valor de cerca do dobro do valor do WCA da amostra sem tratamento, o que transforma a sua superfície de hidrofílica para hidrofóbica, possibilitando novas possibilidades de usos em engenharia. / Polytetrafluoroethylene (PTFE) and polyamide 6 (PA 6) are polymers that have excellent mechanical, electrical and chemical properties. Therefore, they are used in diverse mechanical and electrical equipment components among many other applications. However, PTFE has a water contact angle (WCA) about of 120º and PA 6 has a WCA about of 60º. This, especially for PTFE, decreases their adhesiveness with other materials. To solve this problem, many techniques have been proposed, such as chemical and plasma treatments. Among them the plasma treatment has the advantage of producing modifications on the surface only, altering the bulk. The objective of this work is to study how the WCA varies as a function of the nitrogen plasma treatment parameters, the gas pressure (p), the applied power (P) and the treatment time (t). Nitrogen plasmas were used in this study since, according the literature, such plasmas significantly reduce the surface contact angle of polymers. Several series of treatment were conducted, for PTFE as for PA 6. Significant reductions in WCA were obtained, including a WCA of 0º notable for p = 2.6 Pa, P = 300 W and t = 30 min, for PTFE as for PA 6. Thus, from the results, within the range of the parameters studied, it was concluded that, in general, the WCA diminishes as the power and as the treatment time increases, and that the WCA has a notable behavior as a function of the gas pressure, initially decreasing to reach a minimum (optimum) value of 0 º for p = 2.6 Pa, and then increasing after this point. The reduction in WCA of the treated samples was a consequence of the increase in surface energy, motivated by the incorporation of surface functionalities. X-ray photoelectron spectroscopy (XPS) was used to characterize the structure and composition of the PTFE and PA 6 surfaces. Roughness and surface contact angles of the polymers were measured using profilometry and goniometry, respectively. XPS analyses reveal, for PTFE, the incorporation of oxygen and nitrogen, for PA 6 the increase of oxygen concentration, and for both the presence of polar chemical groups on the treated surface. Measurement of the WCA as a function of the time after the treatment, showed that, for PTFE and PA 6, the WCA tends to increase, stabilizing after about 90 days, when, for PTFE, it reaches about of 80% of the value for virgin PTFE. PA 6 showed a notable result, the WCA stabilized at about double the value of the WCA of virgin PA6, indicating a switch from a hydrophilic to a hydrophobic surface, thus enabling new uses as an engineering polymer.

Lors de ce travail nous avons étudié les modifications de HDPE, PVF, PVDF et PTFE par des plasmas O2 et N2. Nous nous sommes focalisés sur l’effet des ions et des neutres. Nous constatons dans tous les cas une modification de la composition des échantillons, cette modification de composition est accompagnée d’une modification de l’énergie de surface. Les traitements plasma greffent de nouvelles fonctions polaires (oxygénées ou azotées) à la surface des échantillons, responsables de l’augmentation de l’énergie de surface. Le PTFE traité par plasma O2 présente lui un comportement particulier. Il est possible de greffer de faibles quantités d’oxygène à sa surface et d’augmenter faiblement son énergie de surface lors de traitements de courte durée à faibles puissances. Les traitements de plus fortes puissances érodent fortement la surface du PTFE sans y greffer de fonctions oxygénées. Les surfaces obtenues sont extrêmement rugueuses et leur énergie de surface est fortement diminuée, nous obtenons des surfaces de type ultra-hydrophobes. Les résultats obtenus lors des traitements plasma ont été comparés à ceux obtenus dans le cas de traitements par des ions O2+/O+ ou N2+/N+. Ceci nous a permis de mettre en évidence une différence de réactivité des échantillons face aux différents traitements. Cette différence de réactivité nous permet de conclure que les ions ne sont pas l’espèce principale responsable de la modification de nos échantillons lors des traitements plasma. Nous avons également pu mettre en évidence une différence de réactivité entre les différents échantillons. Le HDPE, PVF et PVDF ont des réactivités semblables alors que le PTFE est beaucoup plus résistant aux modifications, nous pensons que ceci est dû à la structure entièrement fluorée du PTFE. Nous avons également étudié la résistance de nos échantillons à l’adsorption de protéines dans le cadre d’une étude sur la biocompatibilité. Nous avons pu montrer que les échantillons de PTFE rendu ultra hydrophobe, après traitement par plasma O2 de haute puissance, présentent une bonne résistance à l’adsorption de protéines. Cette caractéristique est intéressante pour la synthèse de matériaux biocompatibles.

Vatten är en viktig resurs inom processindustrin. Dess användning sträcker sig över olika processområden där exempelvis utspädning av kemikalier och rengöring förekommer. Införande av strängare utsläppskrav, ökade kostnader för vattenrening och begränsning av vattentillgång leder till att effektivisering av vattenanvändning inom vattenkrävande processer ses som ett viktigt arbete. Papperstillverkning är en vattenkrävande process och ständiga förbättringar med avseende på färskvatten intag och avloppsgenerering är önskvärda att genomföra. För att kunna uppskatta förbättringsmöjligheten i en process kan en vatten-pinchanalys tillämpas. I vatten- pinchanalys ingår framtagning av processinformation, framtagning av målvärden och nätverksdesign som nyckelsteg. Vid framtagning av processinformation kartläggs sänkor, dvs enhetsoperationer som kräver vatten av en viss kvalitet, och källor som är enhetsoperationer som genererar vatten i systemet. Målvärden utgörs av det minimala intaget av färskvatten och avloppsgenerering. Syftet med arbetet är att undersöka hur vatten-pinchanalys kan tillämpas i papperstillverkningsprocessen. I detta arbete har vatten-pinchanalys tillämpats på två fallstudier som behandlar papperstillverkningen. Målet med arbetet är att ta fram en validerad Excel-modell med inbyggd målframtagningsmetod och använda modellen vid genomförandet av vatten-pinchanalys vid papperstillverkning. Målet är även att kunna ge rekommendation på hur framtagning av processinformation ska genomföras i papperstillverkningsprocessen utifrån en känslighetsanalys. Arbetet resulterade i att vattenkaskadanalys användes som metod för målframtagning och byggdes in som en Excel-modell. Vidare användes närmastegrannen metoden för design av vattennätverk där maximering av vattenåteranvändning sker. Den skapade Excel-modellen som togs fram validerades mot publikationer som tillämpat vattenkaskadanalys. Som resultat erhölls en skillnad på mindre än 1 % mellan Excel-modell och publikationer där vattenkaskadanalys tillämpats. Detta leder till att Excel-modellen bidrar till en automatiserad framtagning av målvärden från papperstillverkningsprocessen. Användning av vattenkaskadanalys och närmastegrannen metoden för vatten- pinchanalys på fallstudiernas data leder till att besparingar i form av färskvatten och avloppsgenerering kan tas fram i papperstillverkningsprocessen. För den första fallstudien skulle intaget av färskvatten till mäldflödessystemet kunna uteslutas helt genom att återanvända befintliga procesströmmar och för den andra fallstudien kan ytterligare användningen av procesströmmen från flotationstanken i det befintliga systemet leda till en minskning av färskvatten intag i formningssektion. Generellt blir press-och formningssektion viktiga för återanvändning av vatten. Framtagning av processinformation utgör grunden i vatten-pinchanalys och för att kunna ta fram det minimala färskvatten intaget till processen som analyseras anses identifierade sänkor i systemet ha en stor betydelse utifrån känslighetsanalysen som genomfördes. Sänkor ska kartläggas så dessa har den högsta tillåtna koncentrationen. Det är även av stor vikt att informationsframtagning om enhetsprocesser med höga massflöden exempelvis formningssektionen genomförs noggrant då även dessa har en stor påverkan på färskvatten intag och avloppsgenereringen. / Water is an important resource in the process industry. Its use extends over various process areas such as dilution of chemicals and cleaning. The introduction of stricter emission requirements, increased costs of water treatment and limitation of water resources means that the efficiency of fresh water use in water-demanding processes is seen as an important topic. Paper production is a water-demanding process and continuous improvements with respect to fresh water use and wastewater effluent are desirable to implement. In order to be able to estimate the possibility of improvement in a process, water pinch analysis can be applied to processes. Water pinch analysis includes the extraction of process information, setting minimum target values and network design development as key steps. Extraction of process information involves, mapping sinks, that means unit operation that require water of a certain quality, and sources which are unit operations that generate water in the system. Minimum target values consist of the minimum freshwater intake and wastewater effluent. The purpose of the work is to investigate how water pinch analysis can be applied in the papermaking process. In this work, water pinch analysis has been applied to two case studies dealing with paper production. The goal of the work is to develop a validated Excel model with a built-in targeting method and apply it in water pinch analysis. The goal is also to provide recommendations on extraction of process information in the papermaking process based on a sensitivity analysis. This work resulted in the use of the water cascade analysis as a method for targeting minimum water requirements and built-in as an Excel model. Furthermore, nearest neighbor algorithm was used for water network design for maximization of water reuse. The developed Excel model was validated against publications where water cascade analysis is applied. As a result, a difference of less than 1% was obtained between the Excel model and publications. Hence the Excel model is considered to contribute automatization of targeting the minimum requirements in the process. The use of the water cascade analysis and nearest neighbor algorithm for water pinch analysis on cases study data leads to savings in the form of fresh water and waste effluent can be mapped in the papermaking process. For the first case study, use of fresh water to the approaching flowsystem could be completely excluded by reusing existing process streams and for the second case study further use of the process stream from the flotation tank will lead to a reduction of fresh water use in the forming section. In general, the pressing and forming section become important for water reuse. Extraction of process information is fundamental in water pinch analysis and in order to be able to obtain the minimum fresh water intake for processes being analyzed, the identified sinks in the system are consider having a great impact based on a sensitivity analysis conducted. The sinks should be mapped with the highest allowed concentration. It is also of great importance that extraction of process information for process operations such as the forming section, is done accurately as these also have a major effect on fresh water intake and the wastewater effluent due to the magnitude of water required in these processes.

This work comprises studies addressing fundamental questions of the diamond surface physics for different doping concentrations of nitrogen and boron, and how doping is reflected in the core shell analysis, valance band structure and work function values. A second aspect of the work is the controllable creation of nitrogen-vacancy (NVs) centers accompanied by comprehensive surface spectroscopy studies (XPS,UPS and MIES). Additionally, in order to increase and stabilize NV negative (NV-), which are required for quantum computing system, studies on diverse oxygen termination procedures has been executed. The efficiency of oxygen termination procedures compared and is confirmed by spectroscopy and wet contact angle (WCA) measurements. Furthermore, an alternative method of hydrogen termination of the diamond surface is proposed and compared to the traditional hydrogen plasma termination. As related side aspect, the deposition of C60 molecules on the diamond surface is performed and investigated by means of UPS and MIES spectroscopy. A distinctive experimental capability of studies is the implementation of the Metastable Impact Electron Spectroscopy (MIES) spectroscopy. This unique surface spectroscopy technique and individual instrumentation design for probing the electronic structure of the outermost surface layer, including measurement examples is introduced in this work.

Lors de ce travail nous avons étudié les modifications de HDPE, PVF, PVDF et PTFE par des plasmas O2 et N2. Nous nous sommes focalisés sur l’effet des ions et des neutres. Nous constatons dans tous les cas une modification de la composition des échantillons, cette modification de composition est accompagnée d’une modification de l’énergie de surface. Les traitements plasma greffent de nouvelles fonctions polaires (oxygénées ou azotées) à la surface des échantillons, responsables de l’augmentation de l’énergie de surface. Le PTFE traité par plasma O2 présente lui un comportement particulier. Il est possible de greffer de faibles quantités d’oxygène à sa surface et d’augmenter faiblement son énergie de surface lors de traitements de courte durée à faibles puissances. Les traitements de plus fortes puissances érodent fortement la surface du PTFE sans y greffer de fonctions oxygénées. Les surfaces obtenues sont extrêmement rugueuses et leur énergie de surface est fortement diminuée, nous obtenons des surfaces de type ultra-hydrophobes.<p>Les résultats obtenus lors des traitements plasma ont été comparés à ceux obtenus dans le cas de traitements par des ions O2+/O+ ou N2+/N+. Ceci nous a permis de mettre en évidence une différence de réactivité des échantillons face aux différents traitements. Cette différence de réactivité nous permet de conclure que les ions ne sont pas l’espèce principale responsable de la modification de nos échantillons lors des traitements plasma.<p>Nous avons également pu mettre en évidence une différence de réactivité entre les différents échantillons. Le HDPE, PVF et PVDF ont des réactivités semblables alors que le PTFE est beaucoup plus résistant aux modifications, nous pensons que ceci est dû à la structure entièrement fluorée du PTFE.<p>Nous avons également étudié la résistance de nos échantillons à l’adsorption de protéines dans le cadre d’une étude sur la biocompatibilité. Nous avons pu montrer que les échantillons de PTFE rendu ultra hydrophobe, après traitement par plasma O2 de haute puissance, présentent une bonne résistance à l’adsorption de protéines. Cette caractéristique est intéressante pour la synthèse de matériaux biocompatibles. <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

No description available.