Dissertations / Theses on the topic 'Adsorption of stray light'

La pollution de l'environnement, sa remédiation et l'obtention de sources d'énergie plus propres et plus efficaces sont des problématiques difficiles auxquels les humains sont confrontés. Parmi les nombreux matériaux développés par les scientifiques, les polymères de coordination cristallins type MOFs sont de plus en plus développés dans plusieurs domaines, du fait de la facilité et la versatilité de leur synthèse. La recherche sur ces matériaux est récente, mais les possibilités qu’offrent ces matériaux pour différentes applications sont énormes.C'est dans ce cadre que nous avons travaillé sur la conception et la synthèse de différents MOF pour la récupération, le recyclage et/ou la dégradation de certains polluants. En utilisant différentes approches de synthèse, nous avons obtenu des matériaux efficaces pour les diffèrent applications ciblées de ces matériaux. Nous pensons que les MOF ont le potentiel pour solutionner certains problèmes cruciaux comme la décontamination de l'environnement
The pollution of the environment, its remediation and to obtain a cleaner and more efficient energy sources are some of the most challenging topics that humans are now facing. Among the several materials that scientists have developed, Metal Organic Frameworks (MOFs) are gaining a lot of attention on several fields due to the easiness and the versatility in which these materials can be designed, synthesized and used. Even when research on these materials is still young, the possibilities that they offer are enormous.It is on this frame that our work group has worked on the design and the synthesis of different MOFs for the recovery, the recycling and/or the degradation of some pollutants of interest. By using different synthesis approaches we have tested the versatility in the synthesis and the possible applications of these materials. We believe that MOFs hold the potential to solve some crucial issues in the recovery of the environment

Objetivo: Estudiar el efecto del LASIK, las cataratas y la opacificación de la cápsula posterior (PCO) en la luz dispersa intraocular y determinar si la medición de la luz dispersa intraocular ofrece un valor adicional en la evaluación de la calidad visual. Métodos: La agudeza visual (AV) y la luz dispersa intraocular (IOSL) fueron medidas antes y después LASIK y capsulotomía posterior y en pacientes antes de ser intervenidos de extracción de cataratas. Adicionalmente, la sensibilidad al contraste fue medida en los pacientes de LASIK. La severidad de las cataratas y la PCO fueron graduadas y comparadas con los valores de AV e IOSL para estudiar la relación entre la opacidad de los medios ópticos y el compromiso de la calidad visual. Se estudió la correlación entre AV e IOSL. Resultados: la AV sin corrección mejoró después del LASIK (1,048 y 0.091 logMAR antes y después respectivamente) mientras que la IOSL permaneció sin cambios (0.98 y 0.96 log s antes y después respectivamente). En presencia de cataratas y PCO, la AV fue menor de lo normal (0.130 y 0.298 logMAR respectivamente) y la IOLS fue mayor de lo normal (1.45 y 1.38 log s respectivamente). La correlación entre AV y IOSL con los grados de severidad de catarata y PCO fue débil. La AV y la IOSL mostraron una débil correlación ante la presencia de cataratas pero no mostraron una correlación significativa después del LASIK ni ante la PCO. Conclusión: El diferente comportamiento de la AV y la IOSL en las tres situaciones clínicas demuestran que puede haber pacientes con valores de AV cercanos a la normalidad y una IOSL elevada, y pacientes con una IOSL cercana a la normalidad con una AV disminuida. Estos resultados indican que la calidad visual puede verse independientemente comprometida tanto por una disminución de la AV como por un aumento de la IOSL, y por lo tanto, ambos parámetros deberían ser considerados al momento de evaluar la calidad visual.
Purpose: To study the effect of LASIK, cataracts, posterior capsule opacification (PCO) and posterior capsulotomy on intraocular straylight and determine if intraocular straylight measurement offers an additional value for the evaluation of visual quality. Methods: Visual acuity (VA) and intraocular straylight (IOSL) were measured in patients before and after LASIK and posterior capsulotomy, and in patients before cataract surgery. Additionally contrast sensitivity was measured in LASIK patients. Cataracts and PCO were graded and compared with VA and IOSL values to study the relationship between ocular media opacity and visual quality impairment. VA and IOSL were tested for correlation. Results: Uncorrected VA improved after LASIK (1,048 and 0.091 logMAR before and after, respectively) whereas IOSL remained unchanged (0.98 and 0.96 log s before and after, respectively). In the presence of cataracts and PCO VA was lower than normal (0.130 and 0.298 logMAR respectively) and IOSL was higher than normal (1.45 and 1.38 log s respectively). There was a weak correlation between VA and IOSL with cataract and PCO severity grades that was statistically significant. VA and IOSL were only weakly correlated in the presence of cataract and didn’t have a significant correlation after LASIK or in the presence of PCO. Conclusion: The different behavior of visual acuity and intraocular straylight in the three clinical situations show that there can be some patients with close to normal visual acuity that have increased intraocular straylight values and patients with normal intraocular straylight values with decreased visual acuity. These results indicate that visual quality can be independently affected by a decrease in visual acuity or an increase in intraocular straylight, and thus both parameters should be considered when assessing visual quality.

Arthrospira (Spirulina) platensis, cianobactéria fotoautotrófica, é importante comercialmente devido ao seu valor nutricional (elevado teor de proteínas, lipídios, vitaminas e minerais), além da presença do ácido graxo γ-linolênico e pigmentos, os quais agregam valor a esta biomassa. Este micro-organismo foi cultivado em fotobiorreator tubular, e os seguintes parâmetros foram avaliados: aplicação de diferentes sistemas de circulação de células, intensidades luminosas, adição simultânea de diferentes proporções de sulfato de amônio e nitrato de sódio como fontes de nitrogênio, adição de dióxido de carbono proveniente de fermentação alcoólica e, finalmente, a aplicação desta biomassa para remoção de metais pesados. Para a avaliação do sistema de circulação de células e da intensidade luminosa foram utilizadas as variáveis dependentes: concentração celular máxima (Xm), produtividade em células (Px), fator de conversão de nitrogênio em células (YX/N), eficiência fotossintética (EF) e teores de proteínas e lipídios da biomassa. Os protocolos de alimentação de nitrogênio e o uso de CO2 proveniente de cilindro ou de fermentação alcoólica foram avaliados com uso das mesmas variáveis já citadas, exceto EF; e, para remoção de Ni2+, Zn2+ e Pb2+ em solução aquosa foram estudados o tempo de adsorção e a influência da concentração inicial de metal em solução; com posterior cálculo da eficiência e capacidade de adsorção, e apresentação de modelos cinéticos e isotermas de equilíbrio. A melhor combinação de resultados em valores médios (Xm = 4055 mg L-1, Px = 406 mg L-1 d-1, YX/N = 5,07 mg mg-1, lipídios totais = 8,94%, proteínas totais = 30,3%, EF = 2,04%) foi obtida nos cultivos realizados com intensidade luminosa = 120 µ mol fótons m-2 s-1. O tipo de sistema de circulação de células utilizado não influenciou estatisticamente quase nenhuma das respostas estudadas e isto indica a possibilidade de substituição do sistema tradicional airlift pelos outros testados neste trabalho. A mistura da menor quantidade de nitrato em relação à de amônio (protocolo I) resultou na melhor combinação de resultados das variáveis dependentes analisadas(Xm = 4,543 g L-1; Px = 0,460 g L-1 d-1; YX/N = 15,6 g g-1; lipídios totais = 8,39% e proteínas totais = 18,7 %). O tipo da fonte de CO2 não exerceu nenhuma influência estatística no crescimento de A. platensis, o que indica a possibilidade do uso do resíduo (CO2) proveniente de fermentação alcoólica nos cultivos desta cianobactéria. A adsorção dos metais pela biomassa seca de A. platensis reduziu à medida que houve aumento da concentração inicial de metal, e a maior eficiência de adsorção foi para o metal Pb2+ (78%). Chlorella quando comparada à Arthrospira foi considerada melhor adsorvente, devido ao maior valor de eficiência de remoção (86,5%). O modelo, cinético de Ho e Mckay e os modelos de equilíbrio de Langmuir e Freundlich se adequaram bem ao processo de adsorção desta célula.
Arthrospira (Spirulina) platensis, photoautotrophic cyanobacterium, is commercially important due its high nutritional value (high content of proteins, lipids, vitamins, and minerals), besides of the presence of γ-linolenic fatty acids and pigments, which add value to this biomass. This microorganism was cultivated in tubular photobioreactor and the following parameters were evaluated: application of different cell circulation systems, light intensities, different protocols of simultaneous ammonium sulfate and sodium nitrate feeding, addition of CO2 from ethanol fermentation and, finally, the application of this biomass to the heavy metal removal. The dependent variables [maximum cell concentration (Xm), cell productivity (Px), nitrogen-to-cell conversion factor (YX/N), photosynthetic efficiency (EF) and proteins and lipids contents] were used to evaluate the influence of cell circulation systems and the light intensities. The nitrogen feeding protocols and the use of CO2 from cylinder or ethanol fermentation were evaluated using the same parameters aforementioned, except EF; and to analyze Ni2+, Zn2+ and Pb2+ removal, the adsorption time and the influence of initial metal concentration were evaluated with subsequent calculation of the efficiency and capacity adsorption. The kinetic models and equilibrium isotherms were also presented. The best combination of responses\' mean values (Xm = 4055 mg L-1, Px = 406 mg L-1 d-1, YX/N = 5.07 mg mg-1, total lipids = 8.94%, total proteins = 30.3%, EF = 2.04%) was obtained at light intensity = 120 µ mol photons m-2 s-1. The cell circulation system did not exert statistical significant influence on almost all the responses, which suggests that the traditional airlift system could successfully be substituted by the others tested in this work. The mixture of the lower amount of nitrate in relation to ammonium (protocol I) (Xm = 4,543 g L-1; Px = 0,460 g L-1 d-1; YX/N = 15,6 g g-1; total lipids = 8,39% and total proteins = 18,7 %) resulted in the best combination of responses\' mean values. The kind of CO2 source did not exerted any statistical influence on A. platensis growth, which suggests the possibility of using the ethanol fermentation residue (CO2) in the cyanobacterium cultivation. The metal adsorption by A. platensis biomass reduced with increasing initial metal concentration and the adsorption efficiency was higher for metal Pb2+ (78%). Chlorella was considered a better biosorbent when compared to Arthrospira because of the higher values of removal efficiency (86.5%). The kinetic (Ho and McKay) and equilibrium (Langmuir and Freundlich) models are well suited to the adsorption process of this cell.

Rare earth elements (REE) are known as the lanthanide series (La-Lu) plus yttrium (Y) and scandium (Sc). REE are essential materials for modern industries and especially for green technologies (wind turbines, batteries, lasers, catalysts, etc.). However, despite their high global demand, their supply is limited such that the EU has cataloged it as critical raw materials. In order to ensure the supply of REE in the future, the search for alternative sources of these elements worldwide has been promoted in recent years. Acid mine drainage (AMD) produced by the Fe-sulphide weathering can effectively leach Fe, Al, SO4, and REE from the host rock. This can lead to high concentrations of these liberated species in the affected waters. Thus, the REE concentrations in AMD can be between two and three orders of magnitude higher than natural waters, as such it can be considered as a complementary source of REE recovery. The increase of pH in AMD by mixing neutral waters results in the precipitation of iron oxy-hydroxysulfate (schwertmannite) from pH 3-3.5, and aluminum (basaluminite) from pH 4-4.5 in the river channels. This process may be accompanied by REE scavenging. Due to its acidity and high metal load, acid mine drainage presents a major environmental problem worldwide, therefore, different treatment systems have been developed to minimize its impact. Disperse Alkaline Substrate (DAS) passive remediation system neutralizes AMD by dissolving calcite, and allowing the sequential precipitation of schwertmannite and basaluminite in separated layers, where REE are preferably retained in the basaluminite-enriched waste. Despite this, there are still no studies describing the adsorption of REE on both basaluminite and schwertmannite in these environments. The REE scavenging mechanism is studied by adsorption on synthetic minerals of basaluminite and schwertmannite as a result of variation to the both the pH and sulfate concentration. A thermodynamic adsorption model is proposed based on experimental results in order to predict and explain the REE mobility in AMD mixtures with neutral waters and in a passive treatment system. Basaluminite and schwertmannite have a nanocrystalline character. Further, schwertmannite has been observed to transform into goethite on weekly timescales, resulting in sulfate release. However, there is a gap of knowledge about basaluminite stability at variable sulfate concentration and pH and its possible transformation to other more crystalline Al-minerals. In this study, basaluminite local order at different pH values and dissolved sulfate concentrations was characterized. Results demonstrate that basaluminite can transform to nanoboehmite in weeks under circumneutral pH. However, the presence of sulfate can inhibit this transformation. Separate adsorption experiments on both basaluminite and schwertmannite were performed with two different concentrations of SO4 while varying the pH (3-7). Results show that the adsorption is strongly dependent on pH, and to a lesser extent on sulfate concentration. Lanthanide and yttrium adsorption is most effective near pH 5 and higher, while that of scandium begins around pH 4. Due to the high concentrations of sulfate in acidic waters, the predominant aqueous REE species are sulfate complexes (MSO4+). Notably, Sc(OH)2+ represents a significant proportion of aqueous Sc. , A surface complexation model is proposed in which predominant aqueous species (Mz+) adsorb on the mineral surface, XOH, following the reaction: The adsorption of the lanthanides and yttrium occurs through the exchange of one and two protons from the basaluminite and schwertmannite surface, respectively, with the aqueous sulfate complexes. The sorbed species form monodentate surface complexes with the aluminum mineral and bidentate with the iron mineral. In the case of Sc, the aqueous species ScSO4+ and Sc(OH)2+ form bidentate surface complexes with both minerals. EXAFS analysis of the YSO4+ complex adsorbed on the basaluminite surface suggests the formation of a monodentate inner sphere complex, in agreement with the proposed thermodynamic model. Once the surface complexation model was validated, it was used to asses and predict the REE mobility in passive remediation systems and acidic water mixing zones with alkaline inputs from the field. The REE are preferentially retained in basaluminite-rich waste during passive remediation due to its sorption capacity between pH 5-6. In contrast, schwertmannite waste contains very little REE because the formation of this mineral occurs at pH lower than 4, which prevents REE adsorption. Further, Sc may be scavenged during schwertmannite precipitation as a result of this low pH The model correctly predicts the absence of REE in schwertmannite precipitates and the enrichment of the heavy and intermediate REE with respect to the light REE in basaluminite precipitates collected in the water mixing zones. However, there is a systematic overestimation of the fractionation of rare earths in basaluminite precipitate. This inaccuracy is mainly due to the fact that the mineral precipitation and adsorption are not synchronous process, while basaluminite precipitates from pH 4, REE adsorption occurs at higher pH values, between 5 and 7, when the water mixture reaches these values and a fraction of the particles have been dispersed.
Las tierras raras (en inglés rare earth elements, REE) son conocidas como el conjunto de la serie de los lantánidos (La-Lu), itrio (Y) y escandio(Sc). Las tierras raras son materiales indispensables para las industrias modernas y en especial para las tecnologías verdes (aerogeneradores, baterías, láseres, catalizadores, etc.). Sin embargo a pesar de su gran demanda mundial, su abastecimiento es limitado, por lo que han sido catalogadas por la UE como materias primas críticas (Critical Raw Materials). Con el objetivo de asegurar el abastecimiento de REE en el futuro, en los últimos años se ha promovido la búsqueda de fuentes alternativas de estos elementos en todo el mundo. El drenaje ácido de mina (en inglés acid mine drainage, AMD) producido por la meteorización de sulfuros de Fe, tiene un alto poder de lixiviación de las rocas, por lo que las aguas afectadas adquieren elevadas concentraciones en disolución de Fe, Al, SO4 y otros metales, como las REE. Así, las concentraciones de REE en AMD son entre dos y tres órdenes de magnitud superiores al resto de las aguas naturales y pueden suponer una fuente complementaria de recuperación de REE. El aumento de pH del AMD por mezcla con aguas neutras da lugar a la precipitación en los cauces de los ríos de oxy-hidroxisulfatos de hierro (schwertmannita), a partir de pH 3-3.5, y de aluminio (basaluminita), a partir de pH 4-4.5; acompañado de la eliminación de las tierras raras. Debido a su acidez y carga metálica, el drenaje ácido de mina presenta un problema medioambiental de primera magnitud, por lo que se han desarrollado diferentes sistemas de tratamiento para minimizar su impacto. El sistema de tratamiento pasivo Disperse Alkaline Substrate (DAS) produce la neutralización de las aguas ácidas por la disolución de la calcita presente en el sistema, permitiendo la precipitación secuencial, de schwertmannita y basaluminita. Las tierras raras quedan retenidas preferentemente en el residuo enriquecido en basaluminita. A pesar de ello, aún no existen estudios que describan la adsorción de tierras raras tanto en basaluminita como schwertmannita en estos ambientes. En esta tesis se estudia el mecanismo de retención de las tierras raras mediante adsorción en minerales sintéticos de basaluminita y schwertmannita, en función del pH y del contenido de sulfato disuelto. Con los resultados experimentales obtenidos, se propone un modelo termodinámico de adsorción para predecir y explicar la movilidad de las tierras raras observada en mezclas de AMD con aguas neutras y en un sistema de tratamiento pasivo. La basaluminita y la schwertmannita presentan un carácter nanocristalino. Es conocido que la schwertmannita se transforma en goethita en semanas, liberando sulfato. Sin embargo, nada se sabe de la basaluminita y su posible transformación a otros minerales de Al más cristalinos. De este modo, la caracterización del orden local de la basaluminita a diferentes valores de pH y sulfato se expone en primer lugar. Dependiendo del pH y el sulfato en disolución, la basaluminita se transforma en diferentes grados a nanoboehmita en semanas, pero tiende a estabilizarse con la presencia de sulfato en solución. Los experimentos de adsorción en basaluminita y schwertmannita con diferentes concentraciones de SO4 realizados para cada mineral y en rangos de 3-7 de pH han demostrado que la adsorción es fuertemente dependiente del pH, y en menor medida del sulfato. La adsorción de los lantánidos y del itrio es efectiva a pH 5, mientras que la del escandio comienza a pH 4. Debido a las altas concentraciones de sulfato en aguas ácidas, las especies acuosas predominantes de las tierras raras son los complejos con sulfato, MSO4+. Además del complejo sulfato, el Sc presenta importantes proporciones de Sc(OH)2+ en solución. En función de la dependencia del pH y de la importancia de la especiación acuosa, se propone un modelo de complejación superficial donde la especie acuosa predominante (Mz+) se adsorbe a la superficie libre el mineral, XOH, cumpliendo la siguiente reacción: La adsorción de los lantánidos y del itrio se produce a través del intercambio de uno o dos protones de la superficie de la basaluminita o de la schwertmannita, respectivamente, con los complejos sulfato acuoso, formando complejos superficiales monodentados con el mineral de aluminio y bidentados con el de hierro. En el caso del Sc, las especies acuosas ScSO4+ y Sc(OH)2+ forman complejos superficiales bidentados con ambos minerales. Complementando el modelo propuesto, el análisis de EXAFS del complejo YSO4+ adsorbido en la superficie basaluminita sugiere la formación de un complejo monodentado de esfera interna, coincidiendo con el modelo termodinámico propuesto. El modelo de complejación superficial, una vez validado, ha permitido evaluar y predecir la movilidad de REE en los sistemas de tratamiento pasivos y en zonas de mezcla de aguas ácidas con aportes alcalinos estudiados en el campo. La preferente retención de las tierras raras en la zona de la basaluminita precipitada en los sistemas de tratamiento pasivo ocurre por adsorción de las mismas a pH entre 5-6. La ausencia de tierras raras en la zona de schwertmannita se debe al bajo pH de su formación, inferior a 4, que impide la adsorción de las mismas. Sin embargo, debido a su menor pH de adsorción, una fracción de Sc puede quedar retenida en la schwertmannita. El modelo también predice correctamente la ausencia de REE en los precipitados de schwertmannita y el enriquecimiento de las tierras raras pesadas e intermedias respecto a las ligeras en los precipitados de basaluminita recogidos en el campo en las zonas de mezcla de aguas. Sin embargo, se ha observado una sistemática sobreestimación del fraccionamiento de las tierras raras en los precipitados de basaluminita. Este hecho se debe principalmente a que la precipitación del mineral no ocurre de forma síncrona con la adsorción, precipitando la basaluminita a partir de pH 4 y adsorbiendo tierras raras a pH más altos, entre 5 y 7, cuando las partículas sólidas han sido parcialmente dispersadas.

The aim of the diploma thesis is to characterize the adsorption properties of probiotic bacteria. Characterization was performed using of designed and optimized spectrophotometric method of determination of adhesion of probiotic bacteria to mucin as the main viscoelastic component of mucus. In order to provide a more detailed description of the adhesion interactions involved in the adhesion of probiotic bacteria to mucin, the viability of selected probiotic bacterial strains Lactobacillus rhamnosus CCM 1825, Lactobacillus plantarum CCM 7039, Lactobacillus delbrueckii subsp. bulgaricus CCM 7190, Lactobacillus acidophilus CCM 4833, Lactobacillus casei CCM 4798, Bifidobacterium breve CCM 7825, Bacillus coagulans CCM 2658 and a potential probiotic strain of Lactobacillus zeae CCM 7069. Moreover, bacterial adhesion to carbohydrates was also determined for all the bacteria tested. The last proposed and optimized technique was dynamic and electrophoretic light scattering characterizing surface properties such as -potential, average size distribution and isoelectric point. From this method, information was obtained on aggregation of bacterial cells and on electrostatic interactions. The combination of these methods was used as a complex tool to characterize adhesion of the tested bacterial cultures as a very specific, sensitive and key parameter of a successful probiotic microorganism that is influence by the multiple effects.

In this work, a new method for mass determination of single low-charged particles in the sub-picogram regime is developed. It opens applications to chemical physics and surface science via determination of growth rates. The method combines the well-known electrodynamic quadrupole ion trap in a UHV-chamber and fourier transformation of scattered light. The achieved mass resolution of down to $10^{-4}$ at 100 fg mass on a time scale of ten seconds allows a resolution of a few percent of the mass of an adsorbed monolayer and to determine growth rates down to one molecule per second on a time scale of one day. The observation of temperature dependent sticking coefficients results in the measures of the energy of an adsorption barrier. Observation of discrete steps in the rate gives information about the density of molecules in an ordered layer. Temperature dependent desorption data gives the binding energy. The dependence of these observables on the controllable curvature and charge of the substrate's surface is measurable. The first part of this dissertation consists of a description of the common theory of the quadrupole ion trap with the completion of not widely known, newly introduced, contributions to the trapping potential. These contributions lead to systematic shifts in the mass determination. In particular the influence of the inhomogenity of the electrical field, that is used for compensating the gravitational force, is investigated analytically and corroborated experimentally. It is assumed, that the particle's finite size effects in a further shift. In the experimental part initial demonstrative measurements are presented: the time-resolved adsorption of fullerene, anthracene and NO on silica spheres with 500nm diameter has been measured at room temperature. In addition the secondary electron yield of in-situ prepared particles during irradiation with monoenergetic electrons has been determined by analyzing the distribution of change of the number of elementary charges by single events of charging.

Un polyélectrolyte hydrophobe est un polymère portant des charges électriques lorsqu'il est en solution aqueuse et dont l'eau est un mauvais solvant pour le squelette. Cette thèse a pour objectif d'établir l'influence de la nature hydrophobe du squelette sur les propriétés physiques des polyélectrolytes. Pour cela, nous avons tout d'abord synthétisé une série de poly(styrène-\emph(co)-styrènesulfonate de sodium), appelés PSS, possédant des taux de charge $f$ variant entre 30\% et 100\% et comportant entre $N=120$ et $N=2520$ monomères par chaîne. Ces PSS sont caractérisés précisément et peuvent être considérés comme des polyélectrolytes hydrophobes modèles. Nous avons alors étudié leurs propriétés volumiques puis interfaciales.\\ \emph(1. Propriétés en volume.) Le taux de charge effectif de la chaîne unique est anormalement réduit par rapport au cas du polyélectrolyte hydrophile. D'autre part, les propriétés structurales ont été caractérisées par la diffusion des rayons X et la technique de la sonde colloïdale en microscopie à force atomique (AFM). La conformation des chaînes se fait ressentir puisque la longueur de corrélation varie comme $N^0C_p^(-\alpha)$ où $C_p$ est la concentration en polymère et $\alpha$ un exposant dépendant de $f$, décroissant de 1/2 ($f=100\%$) à 1/3 au voisinage de la limite de solubilité. Ces observations sont interprétées dans le cadre d'un modèle théorique prédisant la conformation de la chaîne isolée comme un collier de perles, constitué de globules denses (les perles) reliés deux à deux par un segment de chaîne étirée. La dynamique collective des chaînes, quant à elle, est très proche de celle des polyélectrolytes hydrophiles.\\ \emph(2. Propriétés aux interfaces.) Nous avons conçu une expérience permettant, par adsorption électrostatique ou hydrophobe, de fixer les chaînes de PSS sur une surface solide plane modifiée chimiquement. La couche de PSS adsorbée, immergée dans l'eau, est caractérisée $in~situ$ par ellipsométrie, réflectivité des rayons X haute énergie et microscopie à force atomique. Nous avons ainsi trouvé que la taille de perles varie entre 1 et 5 nm en fonction de $f$. Cette variation est en parfait accord avec les prédictions du modèle dit du collier de perles. Enfin, les polyélectrolytes hydrophobes s'adsorbent également aux interfaces hydrophobes, les perles, dans certains cas, s'étalant sur la surface.

碩士
國立高雄應用科技大學
機械與精密工程研究所
97
Stray light is the unfunctioned light in optical systems which reduces the image contrast and optical quality. Controlling stray light is essential to the success of designing optical systems. Stray light is always exists in optical systems, but we can reduce it to a reasonable order by using suitable opto-mechanical designs. In this paper, we first analyze the stray light of a night vision system of which the construction data are provided by the manufacturer and then identify the critical and illuminated surfaces as well as the stray light paths. Finally, the stray light is well reduced by using blocking apertures and blacking the edges of some important lens elements.

碩士
國立中央大學
光電科學研究所
98
This paper analyses and suppresses the stray light for a 3 mega pixel and 3x zoom lens of the mobile phone. Established the fabrication components to the zoom lens and observed the average illumination and the illumination chart on the sensor for source incidence from many angles by using LightTools. Classified the stray light to route and coating, blackened, and changed the shape of the CA for aspherical lens are the corrected ways for suppression. After simulated by using LightTools, compared the average illumination and the illumination chart on the sensor and the efficiency.

碩士
國立虎尾科技大學
光電與材料科技研究所在職專班
96
The stray light problem in the cell phone lens differs from those in a camera and a projector. The stray light in a camera or a projector normally is caused by the cone reflection or light leak of a rim. If we change the structure and shape of baffle or reduce the length of diameter of a sheet, the stray light can be avoided to a certain level. For the cell phone lens, due to its small size, the rim structure of lens may cause light reflection and lead to stray light. In this thesis, besides reducing the diameter of a sheet or changing the structure and shape of a baffle, we study the method on suppressing the stray light by changing the lens structure outside the effective diameter. IA two-piece lens for mega pixel cell phones is used in our experiment. We perform the simulation of the trace of stray light for and use traditional methods to make primary improvement. Then, we perform adjustments based by change the shape of lens rim. When traditional method of reducing the size of effective diameter is applied, the average stray light energy is improved from 0.083% to 0.019%. By changing the lens structure outside the effective diameter, the average stray light energy is further reduced to 0.003%.

碩士
國立虎尾科技大學
光電與材料科技研究所在職專班
100
Currently, there is a broad application using optical lenses. They are cellular phones, cameras, projectors, monitor etc.; however, their images exhibit ghosting and flare effect. They are subject to unclear images; therefore, there is a need for improving and optimizing lens properties. With the aid of using optical software and optical thin film coating technology, a design with reduced ghosting can be achieved, also reducing stray light generated on the lenses. By introducing spectroscopy measurement (wavelength ranging from 450nm to 660nm) of four to six layers coatings, the average reflectivity can be reduced from 0.73% to 0.76% and 0.43% to 0.48%, respectively. When using six-layer coating lens, the reflectivity can be significantly reduced, but ghosting and flare still persist. If an optical optimization software is utilized for thin film coating design and assuming that these incident lights are being focused at the same location, the ratio of ghosting is decreased to 0.0006, which is a substantial improvement. With these improvements, this design is practically applicable to optical lenses. 　　We mainly focus on the ghosting and flare induced in cell phone and plastic lenses. The goal is to reduce the ghosting and flare effect at most; optimization is achieved by using the anti-reflective coating of thin film, with the help from the use of lens design software in order to sustain optimal solution. The effectiveness of the proposed scenario is demonstrated; it can be applied in the manufacturing process of plastic lenses.

碩士
國立高雄應用科技大學
機械與精密工程研究所
99
This study aims to discuss the feasibility of the analysis and suppression of stray light in optical lenses. Suppression of stray light is generally essential to obtain high contract image. We firstly use Visual Basic to create the optical lenses and evaluate the proper positions and sizes of the baffles within the barrels. Then, those data are transferred to the optical software LightTools for further analysis and suppression of the stray light. This study defines PST function is attenuation factor. In the beginning, simple singlet of which the source of stray light are more easily to be found are investigated. We also study lenses with three and more elements. Optimizing the shapes of mechanical parts, blacking optical lens edges and a barrel, setting baffle system, including threads and searching illuminated and critical objects by LightTools’s ray path function are all considered. At last, we have efficiently distinguished the sources of ghost from the stray light, created suitable shape of sawtooth instead of using baffles, and finally reduced the PST value to about 1/100 for a zoom 8mm movie camera lens.

碩士
國立高雄第一科技大學
電機工程研究所碩士班
103
In the recent years, smart phones and portable device sales goes strongly. In addition, thin and lightweight play the role at 3C market so that traditional lens will face great challenges. Besides, demand of miniature zoom optics is increasing so that we have to think about optics of next generation, “Optics Next”. The potential pioneer of optics next, Array Camera will play the significant role. 　　In this research, the miniature lens design with freeform surface is based on the current precision injection molding. In this research, the miniature lens design with freeform Surface and sphere surface replace traditional lens design. In addition, the use of an array of camera parallax to reduce the influence of stray light. 　　In the recent years, there are many companies such as ITRI and TSMC in Taiwan. If this innovation will be breakthrough, it is beyond doubt that it will be a great contribution on the industry technology in Taiwan, even will become an emerging industry.

This thesis discusses research on the adhesive bonding of organosilanes to alloys of Al and Mg using surface analysis techniques (especially secondary-ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM)). One project involved comparing the adsorption of bis-1,2-(triethoxysilyl)ethane (BTSE) on high-purity Al, and on anodized 7075-Al alloy, for different pre-treatments involving chemical and heating procedures, and exposure to a H₂ plasma. The objectives were to assess the effects of these pre-treatments on the direct Al-O-Si covalent bonding and the strength of the adhesive coating. The separate adsorption of BTSE and γ-glycidoxypropyltrimethoxysilane (γ-GPS) on an air-oxidized mirror-polished 7075-Al surface was studied with an emphasis on the different microstructural regions of the alloy surface with scanning Auger microscopy (SAM). BTSE at its natural pH (4.3) adsorbed on the Al-Cu-Mg and Al-Fe-Zn types of second-phase particles, and on the alloy matrix, while γ-GPS adsorbed on all these regions only after the starting pH was reduced from its natural value (5.7) to 3.2. However, with prior heating of the sample (200°C, 15 min), γ-GPS adsorption occurred on all regions even at pH 5.7. Time-of-flight (TOF)-SIMS was used for the first time to indicate the nature of the metal-O-Si bonding at the different micro-regions. The Mg-based alloy AZ91 was characterized with regard to its different surface micro-regions both from mirror-polished and fractured surfaces, as well as oxide growth and oxide stability on heating. There is a clear tendency for Mg oxidation, which covers the Al component, while other elements (Zn and Mn) are detected only with bulk characterization methods, although localized Mn-rich particles (dimensions ~3 μm) are identified by SEM and energy-dispersive X-ray (EDX) spectroscopy. In a coating environment (by 1% solutions of BTSE, γ-GPS, γ-APS at their natural pH values) the Mg oxide is etched, and adsorption occurs on the different regions of the alloy, but the attachment is weak, especially because of the fragile nature of the underlying substrate. However 4% BTSE (at pH 3.9) formed a thicker and denser coating with better prospects for substrate protection.
Science, Faculty of
Chemistry, Department of
Graduate

碩士
國立虎尾科技大學
光電與材料科技研究所
97
The topic of this research is trying to analyze and improve the stray light of the embedded camera lens unit by applying the Single Wavelength Collimated Laser. First, to review the image quality with the stray light and then simulate the stray light image, energy , and the path of the single straight light. Second, according to optical simulated angle to verify the stray light path by applying the Single Wavelength Collimated Laser. Therefore, we analyzed the stray light energy by the image quality so as to correct the stray light by simulation results which can help us to realize if we can get the better improvement in the system in comparison. According to this research experiment, the result can be used to eliminate almost stray light in the image and improvement yield rate closely to 99%. By this experiment verification we can find out the stray light path and measure the energy which can help us improve the process or change optical /mechanical design to eliminate the stray light to get better image quality.

碩士
國立中山大學
物理學系研究所
90
Surface Laser Light Scattering (SLLS) is a heterodyne detection technique used to probe the surface properties of fluid interfaces. These interfaces are either liquid/liquid or vapor/liquid, and they may include insoluble monolayers or polymer films deposited on liquid surfaces as well as microemulsions in solution at low concentration. This technique provides one with a nonperturbative way to obtain surface tension and viscosity. A diffraction grating is employed to provide a stable local oscillatior, hence selecting an accurate ripplon wave vector . This thesis deals with the investigation of the interface between air and solution consisting of the methanol and water mixture and poly(N-isopropylacrylamide) or PNIPAM which is one of the fascinating polymeric materials. The polymer PNIPAM shows distinct responses to variations in the surrounding environment (such as thermal gradient, change in pH, etc.). The surface tension extracted from the SLLS data using the Kelvin equation is found to agree well with that obtained by using the Wilhelmy plate method. For the range of wave vectors cm-1, the power spectrum detected in frequency domain can be fit to a Lorentzian profile. Our experiments show that when the volume percentage of methanol increases, the interfacial property becomes insensitive to the presence of PNIPAM.

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Engineering (Metallurgy and Materials Engineering) October 2017
In petroleum industry, sulphur compounds are undesirable due to potential corrosions and environmental challenges associated with these compounds. Sulphur occurs in varies forms in crude oil and petroleum products such as, marcaptans, disulphide, sulphides, disulphide H2S and thiophenes. Commercial scale refineries utilises hydrodesulphurisation to reduce the sulphur content in fuels, though this technology is associated with high operating and capital cost. Extractive, adsorptive, oxidative, membrane separation and bio desulphurisation are some of the alternative technology being investigated which have proven not to be as efficient and/or cost effective as compared to hydrodesulphurisation. Adsorption desulphurisation has been effective in separation processes where the sorbate concentrations are low and this technology was used to evaluate the performance of the polymer supported imidation agent (Sodium N-chloro-polystyrene sulphonamide) as an adsorbent in diesel fuel desulphurisation. A mathematical model simulating adsorption on a fixed was developed. This model incorporates internal mass transfer assuming laminar flow, constant interstitial velocity and an isothermal system. To represent liquid solid equilibrium the Langmuir isotherm was used. The model contains partial differentiate equation that were linearised by using the Euler’s forward implicit method, this enabled simulating the model using Microsoft Excel Visual Basic. The obtained simulation results were compared against experimental data. The impact of varying parameters such as initial sulphur concentration, adsorbent bed porosity and external bed surface area per particle volume was studied in detail. Existing isotherms and kinetics were discussed by using experimental data from Fadhel’s study. It was found that the adsorbate residence time is reduced by smaller adsorbent bed porosity resulting in increased adsorption rate. By decreasing the adsorbent particle diameter and an increase in initial sulphur concentration, the breakthrough time is decreased. The experiment data agreed with the simulation results and this validate that the proposed model is applicable to study the performance of fixed bed adsorption processes under isothermal conditions, no axial mixing and constant interstitial velocities. The results from the analysed Fadhel’s data showed that the modelled light oil can be desulphurise to the Euro 5 level requirements, Sulphur <500ppm, by both Chloramine T and Synthesis PI, a complete sulphur removal was achieved using both adsorbents. The desulphurisation rate proved to be faster with Chloramine T as an adsorbent as compared to Synthesis PI. Modelled light oil adsorption obeyed the pseudo-first-order kinetics and the overall adsorption rate was controlled by the chemisorption process. The diesel fuels study by Fadhel could not be desulphurised to the Euro 5 level. The diesel fuel 1 sulphur concentration was reduced from 12 354 to 11 200ppm and diesel fuel 2 from 1 900 to 800ppm. It was observed that the rate of desulphurisation proved to be faster with diesel fuel 1 as compared to that of diesel fuel 2. The Freundlich isotherm was found to be a best fit in the adsorption of diesel fuel 1, the attained R square values was 0.881 and 0.435 for Freundlich and Langmuir, respectively. Also the obtained Langmuir separation factor, RL , of 1 confirmed the that the Langmuir adsorption was unfavourable. This implies that the adsorption rate was controlled by a physisorption process. The diesel fuel 2 desulphurisation process did not fit the studied adsorption isotherms, the attained R square values was 0.433 and 0.218 for Freundlich and Langmuir, respectively. The Langmuir separation factor confirmed in-favourability at 1 and the Freundlich adsorption strength was 6.052, which is very low as compared to that pf diesel fuel 1 at 272.41. Diesel fuel 1 adsorption reaction obeyed the pseudo-second and pseudo-first order kinetics when reacted with Chloramine T and Synthesis PI, respectively. The obtained R squared values were 0.694 and 0.999 for pseudo-second and pseudo-first order, respectively. Diesel fuel 2 obeyed the third order kinetics with both Chloramine T and Synthesis PI, with R squared values calculated at 0.889 and 0.774 for Chloramine T and Synthesis PI reaction, respectively.
XL2018

碩士
國立臺南大學
電機工程學系碩博士班
102
In this study, ZnO seed layer was grown by Successive Ionic Layer Adsorption and Reaction,(SILAR) method. This experiments were carried out a low temperature of 95℃ in normal pressure conditions. ZnO nanostructure with different diameters and densities were grown on ZnO nanosheets on surface of the AlGaInP-based LEDS with seed layer cycles 2, 4, 6and 8, respectively, then growing the zinc oxide nanosheets in the same time by using the SILAR method 1:1 ,and zinc nitrate [Zn(NO3)2] and hexamethylenetetramine (HMT) [C6H12N4] mixed solution to growing zinc oxide nanostructure. Compared to a regular AlGaInP-based LED, the proposed LEDs with nanostructures show the enhancement in light output power by 30%, 36%, 47% and 22% at 20mA from 2cycle to 8 cycles. After that we used the same method were grown ZnO nanorods on GaN-based LEDs. The output power could be enhanced 37% under 20mA current injection as compare with the standard surface LEDs. The improvement of light extraction efficiency was attributed to the reduction of internal reflection loss and Fresnel’s loss at the GaN-air interface. Finally ZnO nanorods were grown on Flip-Chip LEDs, the maximum output power could be enhanced 24% under 350mA current injection as compare with the standard surface LEDs. Roughness of surface enables some light to escape through the semiconductor to air ,and attributed to decreasing free-carrier light absorption in the material. ZnO nanostructure prepared by SILAR method is very effective in improving the light extraction.

碩士
國立臺灣師範大學
化學系
101
Since in 2004,graphene , a two-dimensional (2D) form of carbon atoms with the honeycomb lattice structure is found due to its variety of outstanding physical properties, including high optical transparency, high conductivity, one-atom thick planar sheet, excellent mechanical strength and very stable chemical properties. Recently, a large-area graphene film has been applied to a large number of optoelectronic devices, and deemed to one of the most promising candidates to replace indium tin oxide (ITO) film. In order to fabricate graphene-based optoelectronic devices, a variety of methods of preparation of graphene film and transfer technology constantly have been developed and improved. However, it is still no effective way to replace indium tin oxide (ITO) by the graphene film. Main problem is how to avoid the completeness and clean of graphene film during transfer process. The graphene film often caused some damages during transfer process and influenced by the organic residues, resulting in bad performance of the optoelectronic devices. In this study, we focused on developing a good transfer method and practically applied the graphene film as electrode in organic light-emitting diode (OLED) applications. The current graphene transfer process is PMMA method and Roll-to-Roll method. These methods must rely on organic material support to make graphene transfer to target substrate. Here, we developed a simple way by utilizing electrostatic adsorption to transfer graphene film from the copper foil to our target substrate. Our process does not require any organic material support and therefore have no residue on the graphene film. Finally, a clean and high-quality graphene film was obtained. The monolayer graphene resistance is approximately 300Ω/sq, ID/IG ~ 0.05. Finally, we used graphene film as a transparent conductive electrode, and applied into organic light emitting diodes, using Alq3 as a light emitting layer. The efficiency of the OLED devices based on residual-free graphene films can be improved.

碩士
國立成功大學
物理學系碩博士班
94
The switching behavior of a TN liquid crystal grating based on the light-induced adsorbed dye molecules on polymer surface was studied. The result shows that liquid crystals are fastly reoriented by the dye molecules adsorbed on polymer surface. In addition, the grating is optically switchable using linearly polarized light. The first-order diffraction intensity, thus, could be controlled by changing the polarization direction of the incident pump light.

碩士
國立中興大學
材料科學與工程學系所
105
Nitrogen-doped Fe3O4@Ag@TiO2-xNx composite particles have been successfully synthesized by solvothermal method using different kinds of dopant including methylamine (MA), diethylamine (DEA), ethyleneamine (EDA), urea (U), and ammonia (A). X-ray diffraction revealed that diffraction peaks pronouncedly broaden and their intensity reduce with the N-doping, indicating that reduced crystallinity and smaller crystalline size resulted. Based on XPS analysis, interstitial nitrogen-doping was found in the titanium dioxide layer of the composite particles. The Fe3O4@Ag@TiO2-xNx composite particles exhibited a high BET surface area of 251.3~431.9 m2/g and a BJH average pore diameter below 10 nm. By SQUID measurement at room temperature, the saturation magnetization (Ms) of the particles was 0.02 emu/g. From UV-vis spectroscopy and Tauc plot, the band gap was determined in the range of 2.4-2.8 eV for the Fe3O4@Ag@TiO2-xNx composite particles. We have also investigated dye degradation of organic dyes in water by dark adsorption and visible light irradiation. Among the nitrogen sources examined, the as-prepared powders show different adsorption ability to methylene blue (MB) and methyl orange (MO) as the solution pH was altered. The dye molecules must be adsorbed on the powder surface, before being photodegraded under the light irradiation. The methylamine-doped particles were found to have ~90% adsorption for the MB dye at pH=2, and ~30% adsorption followed then by ~20% photocatalytic activity for the MO dye. At pH=9, the methylamine-doped ones showed ~100% adsorption for the MB dye but there was no adsorption for the MO dye. The urea-doped ones showed ~40% adsorption followed then by ~30% after visible light irradiation at pH=2, but there was no significant effect for the MO degradation. In addition, the initial dye concentration was varied, and the methylamine-doped composite particles appeared to exhibit a multilayer adsorption behavior when the dye concentration was below 2.5x10-5 M. The methylamine-doped powders were recycled by an external magnetic field and were re-used for the dye removal. The particles showed a degradation rate nearly 95% after up to five times of use. Finally, Ag could be slowly released from the composite particles through the mesoporous shell structure. The release of Ag was found after immersion in water for 48 h, indicating long-lasting bactericidal ability.

碩士
國立成功大學
光電科學與工程研究所
97
This thesis studies the alignment properties of liquid crystals by the adsorbed azo dyes (methyl red; MR) excited by elliptically polarized green laser beams with various ellipticities in azo dye-doped liquid crystals (ADDLCs). Firstly, an elliptically polarized green laser beam with its major axis being parallel to the liquid crystal director was used as the pump beam. Experimental results showed that MR molecules were adsorbed along multiple directions due to the symmetry light-absorbance by MR molecules. In other words, multi-domain adsorption was generated. Secondly, by overcoming the shortage of multi-domain adsorption, the major axis of the pump beam was changed to make an angle of +45o with the liquid crystal director. In this part, the alignment properties of the adsorbed MRs generated by illuminating elliptically polarized green laser beams with various ellipticities having a fixed light intensity or a fixed light component along the direction of major axis were studied. The experimental results indicated that the light-induced MR molecular reorientation effect, the so-called twisted angle, caused by the adsorbed MR, decreased with increasing ellipticity of the elliptically polarized green light. Notably, zero pre-tilt angle of LC alignment was achieved in this experiment. Thirdly, the MR adsorption effect recorded by circularly polarized green laser beams with various intensities was studied. Experimentally, neither the twisted angle nor the tilt angle was produced using circularly polarized green light. Additionally, the nucleation phenomenon, which caused a nonuniform adsorption layer was observed. Finally, the direction of the MR adsorption was found to be independent of the sign of the light ellipticity, but dependent on the direction of the major or minor axis of the elliptically polarized green pump beam. Moreover, the ripple structures of the adsorbed dyes, which were observed using a linearly polarized green pump beam were not observed in the cases pumped by elliptically or circularly polarized beam.

The aim of this work is to contribute for the development of adsorption based separation processes with considerable potential for commercial application on the refining industry, namely, in the separation of high research octane number (HRON) paraffins from light naphtha fractions. The development of an adsorption process requires first a detailed knowledge of equilibria and kinetics of adsorption and their impact on the dynamic response of an adsorption column. Accordingly, we start collecting single and mixture adsorption equilibrium isotherms of C6 isomers, n-hexane (nHEX), 3-methylpentane (3MP), 2,3-dimethylbutane (23DMB), and 2,2- dimethylbutane (22DMB), from breakthrough experiments in zeolite beta. This adsorbent was selected because its pore system posses interesting characteristics for the separation of HRON dibranched C6 from their low research octane number (LRON) monobranched isomers. It was found that the sorption hierarchy in zeolite beta was most favourable towards the linear isomer and least favourable towards the dibranched ones. Zeolite beta demonstrated significant selectivity to discriminate between mono and dibranched C6 isomers, especially at low coverage. Based on an analysis of sorption events at the molecular level, a Tri-Site Langmuir model (TSL) was developed to interpret the equilibrium data with good accuracy. Sorption kinetics studied by zero-length chromatography technique allowed us to find the nature of controlling diffusion mechanism; for nHEX and 3MP macropore diffusion is controlling. For 23DMB and 22DMB, the system is governed apparently by both macropore and micropore diffusion. The dynamics of equimolar C5/C6 paraffin fractions in a fixed bed of zeolite beta was studied. Breakthrough experiments demonstrate that the sorption hierarchy is temperature-dependent. At 583 K, an enriched HRON fraction of 22DMB, iso-pentane (iPEN) and 23DMB can be selectively separated from the isomerate feed. For the case of feed mixtures with the typical composition of the hydroisomerization reactor product, the enriched fraction contains LRON n-pentane (nPEN) which decreases the octane quality of the product obtained. However, the use of a layered bed with zeolite 5A and zeolite beta can displace the nPEN from the enriched fraction, resulting in a maximum octane number of about 92.5 points. Aspen Adsim was used to simulate the dynamic behaviour of the C5/C6 fraction in a non-isothermal and non-adiabatic bed giving a good description of the set of experimental data. An optimal design of a mono/dibranched separation process can be achieved by properly tuning the operating temperature and the zeolite 5A/zeolite beta ratio on a layered fixed bed. The performance of a layered pressure swing adsorption (PSA) process for the separation of HRON paraffins from a C5/C6 light naphtha fraction is simulated using a detailed, adiabatic single column PSA model. A zeolite 5A layer is used for selective adsorption of LRON n-paraffins while a zeolite beta layer is used to reduce the concentration of the LRON 3MP in the HRON fraction. The effects of various independent process variables (zeolite 5A-to-zeolite beta ratio, purge-to-feed ratio, cycle time, depressurization mode and operating temperature) on the process performance (product RON, HRON molecules recovery, HRON purity, and process productivity) are evaluated. It is demonstrated that an optimal zeolite 5A-to-zeolite beta ratio can improve the product average RON of up to 1.0 point comparatively to existing processes using zeolite 5A only. Moreover, process simulations demonstrated that an increase of 20 K in the operating temperature results in octane gain of 0.2 RON. The study and development of membrane technologies was also included in this work as an alternative to PSA processes. The preparation of supported zeolite beta membranes was successfully achieved by exploring several combinations of seeding techniques and synthesis methods. The surface of the membranes was completely covered by well intergrown crystals. The quality of the membranes was tested by means of pervaporation of ethanol/1,3,5-triisopropylbenzene mixtures together with permporometry experiments. The performance in the vapour separation of quaternary equimolar mixtures of C6 isomers showed that permeate flux decreases as the branching degree increases following the order: nHEX>>3MP>23DMB>22DMB. In the retentate, the fractions of 3MP and nHEX decrease while the concentration of dibranched isomers is increased compared to the feed composition. The RON of the quaternary mixture was enhanced up to 5 points with the best synthesized membrane. The potential application of the novel metal-organic frameworks (MOFs) as an alternative to zeolites was also addressed. A screening study for mixtures of C6 isomers was performed in three different MOFs.The first is a rigid zirconium terephthalate UiO- 66, which possesses two types of cages of diameter 12 Å and 9 Å; the second is a chromium trimesate MIL-100(Cr), which possesses a rigid structure with giant cages accessible through 5-9 Å microporous windows; and the third is the flexible Zn2 (BDC)2(H2O)2·(DMF) (MOF-2), in which the pore system contains 1-D large channels. Multicomponent equimolar experiments show that UiO-66 exhibits inverse shape selectivity for C6 isomers, being the retention governed by the rotational freedom of the molecules in the small cages. In the MIL-100(Cr), the sorption hierarchy is similar to the one found in zeolite beta. Finally, MOF-2 exhibits extraordinary n/iso selectivity, by making use of an unusual guest-dependent dynamic behaviour to exclusively take up nHEX, while hindering the access of branched C6 isomers to the pore system.
Fundação para a Ciência e a Tecnologia e ao Fundo Social Europeu, FEDER

The aim of this work is to contribute for the development of adsorption based separation processes with considerable potential for commercial application on the refining industry, namely, in the separation of high research octane number (HRON) paraffins from light naphtha fractions. The development of an adsorption process requires first a detailed knowledge of equilibria and kinetics of adsorption and their impact on the dynamic response of an adsorption column. Accordingly, we start collecting single and mixture adsorption equilibrium isotherms of C6 isomers, n-hexane (nHEX), 3-methylpentane (3MP), 2,3-dimethylbutane (23DMB), and 2,2- dimethylbutane (22DMB), from breakthrough experiments in zeolite beta. This adsorbent was selected because its pore system posses interesting characteristics for the separation of HRON dibranched C6 from their low research octane number (LRON) monobranched isomers. It was found that the sorption hierarchy in zeolite beta was most favourable towards the linear isomer and least favourable towards the dibranched ones. Zeolite beta demonstrated significant selectivity to discriminate between mono and dibranched C6 isomers, especially at low coverage. Based on an analysis of sorption events at the molecular level, a Tri-Site Langmuir model (TSL) was developed to interpret the equilibrium data with good accuracy. Sorption kinetics studied by zero-length chromatography technique allowed us to find the nature of controlling diffusion mechanism; for nHEX and 3MP macropore diffusion is controlling. For 23DMB and 22DMB, the system is governed apparently by both macropore and micropore diffusion. The dynamics of equimolar C5/C6 paraffin fractions in a fixed bed of zeolite beta was studied. Breakthrough experiments demonstrate that the sorption hierarchy is temperature-dependent. At 583 K, an enriched HRON fraction of 22DMB, iso-pentane (iPEN) and 23DMB can be selectively separated from the isomerate feed. For the case of feed mixtures with the typical composition of the hydroisomerization reactor product, the enriched fraction contains LRON n-pentane (nPEN) which decreases the octane quality of the product obtained. However, the use of a layered bed with zeolite 5A and zeolite beta can displace the nPEN from the enriched fraction, resulting in a maximum octane number of about 92.5 points. Aspen Adsim was used to simulate the dynamic behaviour of the C5/C6 fraction in a non-isothermal and non-adiabatic bed giving a good description of the set of experimental data. An optimal design of a mono/dibranched separation process can be achieved by properly tuning the operating temperature and the zeolite 5A/zeolite beta ratio on a layered fixed bed. The performance of a layered pressure swing adsorption (PSA) process for the separation of HRON paraffins from a C5/C6 light naphtha fraction is simulated using a detailed, adiabatic single column PSA model. A zeolite 5A layer is used for selective adsorption of LRON n-paraffins while a zeolite beta layer is used to reduce the concentration of the LRON 3MP in the HRON fraction. The effects of various independent process variables (zeolite 5A-to-zeolite beta ratio, purge-to-feed ratio, cycle time, depressurization mode and operating temperature) on the process performance (product RON, HRON molecules recovery, HRON purity, and process productivity) are evaluated. It is demonstrated that an optimal zeolite 5A-to-zeolite beta ratio can improve the product average RON of up to 1.0 point comparatively to existing processes using zeolite 5A only. Moreover, process simulations demonstrated that an increase of 20 K in the operating temperature results in octane gain of 0.2 RON. The study and development of membrane technologies was also included in this work as an alternative to PSA processes. The preparation of supported zeolite beta membranes was successfully achieved by exploring several combinations of seeding techniques and synthesis methods. The surface of the membranes was completely covered by well intergrown crystals. The quality of the membranes was tested by means of pervaporation of ethanol/1,3,5-triisopropylbenzene mixtures together with permporometry experiments. The performance in the vapour separation of quaternary equimolar mixtures of C6 isomers showed that permeate flux decreases as the branching degree increases following the order: nHEX>>3MP>23DMB>22DMB. In the retentate, the fractions of 3MP and nHEX decrease while the concentration of dibranched isomers is increased compared to the feed composition. The RON of the quaternary mixture was enhanced up to 5 points with the best synthesized membrane. The potential application of the novel metal-organic frameworks (MOFs) as an alternative to zeolites was also addressed. A screening study for mixtures of C6 isomers was performed in three different MOFs.The first is a rigid zirconium terephthalate UiO- 66, which possesses two types of cages of diameter 12 Å and 9 Å; the second is a chromium trimesate MIL-100(Cr), which possesses a rigid structure with giant cages accessible through 5-9 Å microporous windows; and the third is the flexible Zn2 (BDC)2(H2O)2·(DMF) (MOF-2), in which the pore system contains 1-D large channels. Multicomponent equimolar experiments show that UiO-66 exhibits inverse shape selectivity for C6 isomers, being the retention governed by the rotational freedom of the molecules in the small cages. In the MIL-100(Cr), the sorption hierarchy is similar to the one found in zeolite beta. Finally, MOF-2 exhibits extraordinary n/iso selectivity, by making use of an unusual guest-dependent dynamic behaviour to exclusively take up nHEX, while hindering the access of branched C6 isomers to the pore system.
Fundação para a Ciência e a Tecnologia e ao Fundo Social Europeu, FEDER

碩士
國立臺南大學
電機工程學系碩士班
100
Abstract In this study, ZnO nano particles were grown by successive Ionic Layer Adsorption and Reaction, (SILAR) method. This experiment was carried out at low temperature 95oC and at normal pressure conditions. ZnO nano particles with different diameters and densities were caused by hydrogen bond between water and ethylene glycol which effected the dispersion and particles size of ZnO. ZnO nano particles were grown on SiO2 thin films on surface as etching mask. After the SiO2 thin films on LEDs was etching by ICP, the output power variation, voltage variation and wavelength spectrums of LEDs were enhanced. SiO2 nanorods with different lengths on LED surface were prepared; the surface roughness effect on wavelength spectrums were investigated, the rough structure enhanced the light extraction efficiency. ZnO nanorods with different diameters and densities were deposited by controlling DI water and ethylene glycol rinsing procedures with different solvent volume ratios (water/ethylene glycol), this result applied to preparing SiO2 nanorods on LED surface as rough structure, the width of rods were controllable and therefore increased extraction efficiency. The effect on the SiO2 nanorods length were discussed, higher rods lead to higher LED light extraction efficiency, higher LED light efficiency is feasible and expected.

碩士
國立中山大學
化學系研究所
106
(1) Newly Designed Cycloplatinated Polymer Dots as Photocatalysts for Visible Light–driven Hydrogen Evolution Overuse of fossil fuels is intensifying air pollution and greenhouse effect. Thus, developing a clean, renewable energy is a matter of utmost urgency. Hydrogen has been identified as a potential energy carrier because of its high energy capacity and environmental friendliness. However, hydrogen does not exist naturally on earth; we have to make it before use it. Nowadays, there are two main pathways to produce hydrogen that is steam methane reforming and water electrolysis. Among these pathways, water electrolysis is considered as a sustainable way to produce hydrogen because its feedstock is water. However, water splitting is an uphill reaction, requiring the energy supplied from an external resource. If this energy can be obtained from a renewable energy source such as solar energy, hydrogen can then be considered as a green energy totally. In this research, we provide a series of cycloplatinated polymer dots as photocatalyst, in which the platinum complex unit is used as a co-monomer and then linked to a conjugated polymer through Suzuki coupling polymerization. After optimizing the ratio of the Pt complexes, the hydrogen evolution rate (HER) of the cycloplatinated Pdots can be enhanced 9-times higher than the pristine Pdots under the same conditions. Furthermore, the enhancement of the reaction time and the stability are observed by introducing the cycloplatinated Pdots as photocatalysts. Based on the outstanding performance, our newly designed Pdots systems are promised to be a new type of photocatalysts for visible light–driven hydrogen evolution. Keywords: Semiconducting polymers, Polymer dots, Photocatalysts, Visible light, Hydrogen evolution (2) Modification Polymer Dots with PEG Moieties to Reduce Non-specific Biomolecular Adsorption Lately, semiconducting polymer nanoparticles with small sizes (< 30 nm) have been new highly fluorescent probes in optical imaging techniques because of their outstanding fluorescence brightness, good photostability, and minimal toxicity to biosystems. Due to hydrophobic polymer composition, some challenges limit Pdots development to the clinic like uptake by the reticuloendothelial system (RES), nonspecific binding, and entrapment in the live. The research shows that the addition of poly-ethylene glycol (PEG) into nanoparticles reduces RES uptake and increases circulation time in vivo versus uncoated one. Pdots formation is driven by hydrophobic interactions, means polymers in the Pdots are physically associated with each other. In many cases, the functional molecules may fall off from the nanoparticles due to the weak non-covalent interactions. In this research, a molecular with PEG moieties was first synthesized and then covalently linked to a conjugated polymer through Suzuki coupling. Based on this covalent linking strategy, we hope the PEGylated pdots could load more PEGylated molecular and diminish non-specific effect in biological environment. Keywords: PEGylation、Polymer dots、Non-specific effect、Bioimaging、FRET。