The integration and use of superhydrophobic surfaces to microfluidic systems were investigated in this work. Superhydrophobic surfaces are believed to have the ability to reduce the hydrodynamic resistance of a microchannel, reduce the risk of clogging due to reduced liquid contact with the microchannel walls and reduce the losses in a microfluidic system. Two superhydrophobic surfaces with different fabrication methods were evaluated. It was found that fabrication methods that add material to the microchannel walls do not work well in microchannels. Methods that instead transform a present surface are more suitable for a microfluidic system. To visualize the superhydrophobic surfaces an AFM and SEM were used. By combining the information a good picture of the superhydrophobic surfaces where sometimes achieved. To investigate the impact of the superhydrophobic surfaces, two different designs of microchannels were created on silicon wafers and compared with microchannels created in polydimethylsiloxane. One design used straight channels and the other aimed to maximize the resistance reduction by patterning the walls of the microchannel. Due to manufacturing issues only the straight channels were evaluated, where it was found that superhydrophobic surfaces can increase the flow rate of a microfluidic system. However, the result was not reproduced easily. The reason is currently unknown but believed to originate from flaws in the manufacturing process. A simple version of a device that uses superhydrophobic surfaces to seal microfluidic systems was successfully used and reused. A device with a more refined design could offer the ability to create microfluidic systems with detachable lids. Finally, to further increase the availability of the properly created superhydrophobic surface an alternative functionalization step should be found.

In this project, fabrication and characterization of nano/microfluidic channels on borosilicate glass substrate were carried out using a Photo/Ultraviolet (UV) lithography method, which has applications in single-cell analysis. In our single-cell analysis glass system, the bacterial cells will be made to sit in the micrometer channels and also the sub-micron size channels around 300 nm is aspired so it helps in passing the fluid to the outlet hole while holding the cells back. This system will help in the microscopic analysis of the bacterial cell growth over generations. A multi-layer mask approach is used to pattern the etch masks on a glass for the consecutive Isotropic wet etching of the glass substrate. Isotropic wet etching is utilized to transfer the patterned structures from a metal mask to the glass and also to under etch the differently sized spacing pitches (area separating nano/microfluidic channels in our design) to obtain sub-micron channel dimensions. Many test structures were designed on the photomask to optimize during the fabrication process with combinations of differently sized channels with differently sized spacing pitches ranging from 300 nm to 300 µm dimensions. In order to obtain this sub-micron sized channels on glass using a UV lithography technique is a challenging task, so the initial aim was to use the designed spacing pitches present between the channels as a platform to isotopically etch and create an under etched space width size in sub-micrometer. But we were able to obtain channel structure in sub-micron scale directly by optimizing multiple steps of the fabrication process. Characterization of the nano/microfluidic channels was done with the help of Optical microscopy and Dektak profilometer to measure the width, depth and uniformity of the structures during the optimization of the lithography process and scanning electron microscope (SEM) images were taken to analyze the channel dimensions and to get images of the fabricated channels.

In this thesis, two important thermo-physical properties of nanofluids: thermal conductivity and viscosity together with shelf stability of them are investigated. Nanofluids are defined as colloidal suspension of solid particles with the size of lower than 100 nanometer. Thermal conductivity, viscosity and stability of nanofluids were measured by means of TPS method, rotational method and sedimentation balance method, respectively. TPS analyzer and viscometer were calibrated in the early stage and all measured data were in the reasonable range. Effect of some parameters including temperature, concentration, size, shape, alcohol addition and sonication time has been studied on thermal conductivity and viscosity of nanofluids. It has been concluded that increasing temperature, concentration and sonication time can lead to thermal conductivity enhancement while increasing amount of alcohol can decrease thermal conductivity of nanofluids. Generally, tests relating viscosity of nanofluids revealed that increasing concentration increases viscosity; however, increasing other investigated parameters such as temperature, sonication time and amount of alcohol decrease viscosity. In both cases, increasing size of nanofluid results in thermal conductivity and viscosity reduction up to specific size (250 nm) while big particle size (800 nm) increases thermal conductivity and viscosity, drastically. In addition, silver nanofluid with fiber shaped nanoparticles showed higher thermal conductivity and viscosity compared to one with spherical shape nanoparticles. Furthermore, effect of concentration and sonication time have been inspected on stability of nanofluids. Test results indicated that increasing concentration speeds up sedimentation of nanoparticles while bath sonication of nanofluid brings about lower weight for settled particles. Considering relative thermal conductivity to relative viscosity of some nanofluids exposes that ascending or descending behavior of graph can result in some preliminary evaluation regarding applicability of nanofluids as coolant. It can be stated that ascending trend shows better applicability of the sample in higher temperatures while it is opposite for descending trend. Meanwhile, it can be declared that higher value for this factor shows more applicable nanofluid with higher thermal conductivity and less viscosity. Finally, it has been shown that sedimentation causes reduction of thermal conductivity as well as viscosity. For further research activities, it would be suggested to focus more on microscopic investigation regarding behavior of nanofluids besides macroscopic study.

The application of silicon nanocrystals as non-toxic bio-labels and downconverters requires their uniform size distribution in order to minimize the inhomogeneous broadening of the photoluminescence peak. In this thesis, we set the basis for their size-separation via the density-gradient centrifugation method. To be more precise, we successfully apply this technique to separate 5 and 10 nm gold nanoparticles from an ensemble by using an engineered medium layer stack. In addition, we explain how atomic force microscopy is used to measure the size of the nanoparticles, with a particular attentionon the removal of unwanted solvent-related effects. As a future plan, we will implement the technique for the size-separation of silicon nanocrystals.

京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第21048号 / 薬科博第91号 / 新制||薬科||10(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 髙倉 喜信, 教授 山下 富義, 教授 小野 正博 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

Lignin is one of the most common biopolymers in the world. Together with cellulose andhemicellulose it constitutes the fibers in the wood. It has a high molecular weight due to its complexstructure consisting of crossed-linked phenolic monomers and is concatenated with different types ofcarbon and ether bonds.In pulping processes, lignin is extracted in large quantities and used on site to produce energy for milloperations but is also removed as a waste product. This enables a product with high resources andaccessibility due to lignin's diverse properties. Therefore, lignin has the potential to be utilized inhigher value applications such as polymer materials, as well as a source of platform chemicals. Atpresent, the value applications of lignin are promising as additives for different kinds of productssuch as emulsifiers and especially as biofuel due to lignin's high carbon content.New technologies for development for utilization lignin are emerging for different kinds ofapplications due to lignin’s biocompatibility. The possibilities of lignin combined with existingresearch of nanotechnology gives opportunities to improve biomedical applications. By designinglignin derived nanoparticles with incorporated magnetic materials, the NPs obtainsuperparamagnetic properties which can be utilized for target drug delivery. This could be promisingagainst intractable cancer such as pancreatic cancer.This report presents a protocol for developing magnetic lignin nanoparticles from the lowestmolecular weight kraft lignin fractions of eucalyptus (hardwood) and spruce (softwood). By a methodof self-assembly, particles with a doughnut and core-shell morphology, as indicated by SEM and TEM,were yielded with a 10-50μL content of water-stabilized magnetite. The particle size distribution andzeta potential were determined by DLS and the possibility of the particles being suitable forbiomedical applications was discussed.

In this master thesis project, attempts were made to synthesize, pore size tailor, and characterize ZIF-8 and several mixed-linker ZIF structures to improve capture of the greenhouse gasses CH4, CO2, and SF6. Three experimental linkers, 2-methylbenzimidazole, 2-aminobenzimidazole, and 5-nitrobenzimidazole were chosen to gradually substitute 2-methylimidazole as the linker in ZIF-8.  This substitution was intended to gradually reduce pore sizes and possibly adding functionality to the apertures present in ZIF-8 (three different series). The methods of synthesis were first evaluated by performance and modified. Three series of ZIF-hybrids were then synthesized and characterized using PXRD, FTIR, 1HNMR, SEM, extensive sorption measurements, and subsequent modeling to evaluate any success tailoring the hybrid ZIF apertures to increase gas sorption. After modifying synthesis conditions, the undertaking was deemed a success as all three linkers were possible to incorporate to some degree. Hybrid ZIFs were mostly XRD-crystalline. The cleaning process was deemed sufficient. Linker incorporation was not complete but increased with the added linker. Sodalite topology was confirmed in ZIF-8 samples and confirmed as modified in hybrid ZIFs. The hybrid ZIFs did indeed show altered sorption results and surprisingly promising results regarding gas selectivity (favoring sorption of one gas over that of another).

Research groups around the world are looking to develop a qubit protected from decoherence for achieving quantum advantage in computations. This would have huge impact on the modern world. The applications are many from drug development to cryptography and many more  elds. Indium-Arsenide Nanowires with an epitaxially matched thin  lm of lead grown with Select-Area-Growth could prove to be a platform for building scalable qubits. The work in this thesis is to create a device capable of measuring the superconductivity of the samples InAs-Pb grown at the Center for Quantum Devices, Niels Bohr Institute. The InAs semiconducting nanowires serves as one dimensional system that could host Majorana Zero Modes if coupled to a superconductor such as Pb. The MZMs emerges at the edges of the nanowires. The device created is a 4-probe device that should be used to measure the induced topological superconductivity inside the device. The project was able to such a device using electron beam lithography techniques and development of the fabrication process of InAs-Pb SAG NW Devices was furthered.

Quantum dots, also known as artificial atoms, are created by tightly confining electrons, and thereby quantizing their energies. They are important components in the emerging fields of nanotechnology where their potential uses vary from dyes to quantum computing qubits. Interesting properties to investigate are e.g. the existence of atom-like shell structures and lifetimes of prepared states. Stability and controllability are important properties in finding applications to quantum dots. The ability to prepare a state and change it in a controlled manner without it loosing coherence is very useful, and in some semiconductor quantum dots, lifetimes of up to several milliseconds have been realized. Here we focus on dots in semiconductor materials and investigate how the confined electrons are effected by their experienced potential. The shape of the dot will effect its properties, and is important when considering a suitable model. Structures elongated in one dimension, often called nanowires, or shaped as rings have more one-dimensional characteristics than completely round or square dots. The two-dimensional dots investigated here are usually modeled as harmonic oscillators, however we will also consider circular well models. The effective potential confining the electrons is investigated both in regard to how elliptical it is, as well as how results differ when using a harmonic oscillator or a circular well potential. By mixing spin states through spin-orbit interaction transitioning between singlet and triplet states becomes possible with spin independent processes such as phonon relaxation. We solve the spin-mixing two-electron problem numerically for some confinement, and calculate the phonon transition rate between the lowest energy singlet and triplet states using Fermi's golden rule. The strength of the spin-orbit interaction is varied both by changing the coupling constants, and by applying an external, tilted, magnetic field. The relation between magnetic field parameters and dot parameters are used to maximize state lifetimes, and to model experimental results. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.</p>

Organic electrode materials are finding increasing use in energy storage devices due to their attractive properties that allow building of flexible and low weight devices in an environmentally friendlier manner than traditional alternatives. Among these organic electrode materials, conducting redox polymers (CRPs), consisting of conducing polymer (CP) with covalently attached redox active pendant groups (PG), have attracted our interests. This is due to the advantageous synergy between CP and PG, e.g. electronic conductivity, high stability and large charge storage capacity. In this thesis polypyrrole has been selected as CP and quinones as PGs. A series of quinone-pyrrole dyad polymers has been synthesized with a variety of quinone substituents, demonstrating the adjustability of quinone formal potentials by choice of substituents. Importantly, in this series we show that the CP-PG redox match, i.e. that the formal potential of the PG is within the conducting region of the CP, is a requirement for fast charge transfer from the electrode to the PGs. Moreover, a series of quinone-pyrrole dyad polymers with various linkers was synthesized, showing that the choice of linker has a pronounced impact on the interactions between the PG and CP. In addition, the temperature dependence of conductance during doping of the polymers reveals the charge transport mechanism. To summarize, the adjustability of the quinone formal potential as well as the fast charge transport in the bulk material ensures the applicability of the CRPs as electrode materials in organic batteries.