This report studies about optical convex and concavelenses, made of liquid materials. Design proposals of the liquidlenses and the required supporting structure (container), as wellas manufacturing method have been investigated. 8 lenses aredesigned: 4 convex and 4 concave. The theoretical expectationsare validated by simulation and experimental results. The methodhave both advantages and disadvantages. The materials in thelenses are water, syrup, benzyl benzoate and bromone naphtha-lene. / Undersökning gällande optiska linser konvexa och konkava, bestående av flytande material. Designförslag av linser och skall, samt tillverkningsmetod har undersökts. De teoretiska förväntningarna validerades genom simulering och experimentella resultat. Metoden visas har både fördelar och nackdelar. Material i de linserna som vi har undersökt är vatten, sockerlösning, bensylbensoat och Bromonaftalen. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm

The synthesis and characterization of step-growth polymers with novel monomers provided materials with tailored properties for emerging technologies. Specifically, multiphase materials (i.e., microphase separated block copolymers) exploit the synergistic relationship of combining polymers with disparate thermal and mechanical properties. The introduction of intramolecular interactions such as hydrogen and ionic bonding into these polymers further tailored their properties for applications including elastomers, electromechanical transducers, and additive manufacturing (AM). A review of recent literature revealed the material properties required for polymeric materials in electromechanical transducers, which aided in the design of polymers for this application. An isocyanate-, catalyst-, and solvent-free approach facilitated the synthesis of segmented polyureas with tunable thermal and mechanical properties. These materials found use as high dielectric elastomers and water-soluble polymers for extrusion-based AM dependent on the backbone composition. Vat photopolymerization (VP) AM served as a technique to 3D printed novel unsaturated polyester resins (UPR). Incorporating a phosphonium ionic liquid as a reactive diluent replaced styrene and reduced the volatility of commonly used UPRs. VP successfully provided 3D structures from these UPRs that demonstrated limited ionic conductivities. An extensive review of the literature surrounding the structure-property relationships of charged block copolymers with varying architectures helped to inform the synthesis of novel, cationic step-growth polymers. The synthesis of a new phosphonium IL facilitated the synthesis of a segmented polyurethane containing a phosphonium-functionalized soft segment for the first time. This phosphonium polyurethane exhibited ionic conductivities comparable to literature examples of block copolymers used for ionic polymer transducers, which suggests that these materials may serve for this application as well. Carbonyldiimidazole provides a novel route towards synthesizing imidazolium ionenes with unique backbone structures. The coupling of poly(ethylene glycol) dibromides with a bis-carbonylimidazole monomer and a commercial aliphatic dibromide led to the formation of segmented imidazolium ionenes. These polymers exhibited significant atmospheric water uptake as well as water solubility. However, the physical properties of the materials suggested that the synthetic procedure resulted in low molecular weights. Suggested future work provides methods for circumventing this issue and proposes next steps for all the projects discussed herein. / Doctor of Philosophy / Emerging technologies require new polymeric materials with intentionally designed properties. Step-growth polymers such as polyesters, polyurethanes, and polyureas find use in many applications of our everyday lives. Although these materials have served mainly as commodity plastics historically, a reimagining of their syntheses and chemical structures makes them accessible for modern technologies. For example, applying green chemistry principles to the synthesis of polyureas resulted in a less toxic synthetic procedure. Polyureas synthesized through this method exhibited elastic properties comparable to classical polyureas and displayed high dielectric constants, which lend them towards use in dielectric elastomer actuators. This chemistry also allowed for the synthesis of water-soluble polyureas, which served as a material for low temperature extrusion additive manufacturing, colloquially known as 3D printing. Vat photopolymerization describes another type of 3D printing that involves the selective curing of liquid resins with light to form a 3D structure. Employing a reactive ionic liquid monomer with a commercially-relevant unsaturated polyester allowed for a nontoxic method of printing these materials, which also imparted ionic conductivity. Finally, the synthesis of positively charged polyurethanes and ionenes led to the production of ionically conductive materials that may find use in polymeric transducers.

The present thesis investigates the application of pressurized mixtures of imidazolium-based ionic liquids with traditional organic solvents for the dissolution and extraction of lignocellulosic biomass, with bamboo as a specific example of renewable biomass. The approach has been unconventional in that the focus has been on solvent mixtures in which the ionic liquid is the minor component. The objective has been to combine the solvating power of the ionic liquid with a traditional solvent such as ethanol to modulate the outcomes of solubility and extractions by tuning the parameters of fluid composition, temperature, and pressure. Working with mixtures of ionic liquids in traditional solvents as process solvents lowers the viscosity of the medium and thus reduces the transport limitations that are often encountered when working with pure ionic liquids. Among other potential advantages are the reductions in overall process cost that are associated with ionic liquids, potentially easier recovery of post-extraction products, and the recycling of the ionic liquids. This thesis has also addressed another important question regarding the thermal stability of the ionic liquids as a processing medium at elevated temperatures and pressures over time, which may negatively impact their recovery and reuse, and may lead to environmentally unacceptable consequences. The dissolution experiments were carried out in a specially designed high-pressure view-cell equipped with sapphire windows for visual or optical observations. Evaluations were made employing standard characterization tools such as Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), UV-Vis Spectroscopy, and Scanning Electron Microscopy (SEM). Thermal stability studies were carried out using a combination of a view-cell and fiber optic UV-Vis capability at high pressures (up to 350 bar) and temperatures (up to 150 ℃). The dissolution of bamboo was first explored using mixtures of 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac) with ethanol at temperatures from 100 to 150 ℃ and pressures from 35 to 350 bar over 4 or 24 h extraction times. The fluid mixtures employed were in the range of 1 - 40 wt % ionic liquid, which is in contrast to relevant dissolution experiments reported in the literature which either use pure ionic liquids or have the ionic liquids as the majority component. The effects of changing the temperature, pressure, and solvent composition on the removal of different components of the bamboo were assessed. Temperature played the most significant role in the amount of material extracted from the bamboo, with higher temperatures resulting in the removal of more lignin than cellulose and greater conversion of crystalline cellulose to the less recalcitrant amorphous form of cellulose. The concentration of ionic liquid in solution was also important, with higher concentrations resulting in more dissolved biomass. Finally, increasing the pressure resulted in higher amounts of dissolved biomass. The next series of studies focused on rigorously assessing the stability of 1-alkyl-3-methylimidazolium acetate and chloride ionic liquids with alkyl chain lengths from 2 to 10 under both isothermal and non-isothermal conditions via thermogravimetric analysis. Isothermal degradation experiments were conducted at temperatures ranging from 100 to 225 ℃ over time periods ranging from two hours to three weeks. Non-isothermal degradation experiments were conducted at heating rates of 5, 10, 15, and 20 ℃/min from room temperature to 650 ℃. The activation energies and pre-exponential factors were assessed with isoconversional integral methods; the activation energies () ranged from 115 to 157 kJ/mol, and the pre-exponential factors (()) ranged from 24-38. The degradation reactions could be described as 1st order, as they often are in the literature, but were best fit by the 3-dimensional reaction model. Ionic liquids with longer alkyl chains on their imidazolium rings decomposed more quickly and at lower temperatures. The thermal stability of the most promising ionic liquids ([EMIM]Ac, [BMIM]Ac, [EMIM]Cl, and [BMIM]Cl) were then assessed more closely at the possible biomass processing conditions that were being considered. The primary interest was determining the effects of various cosolvents on the thermal stability of these ionic liquids at the process temperatures and pressures, from 100 to 150 ℃ and 35 to 350 bar. These evaluations were carried out in the same high-pressure view cell in which the extraction experiments were conducted. To assess the degradation of the ionic liquids, time-evolved UV spectra of the mixtures were generated. It was found that more protic solvents such as water attenuated the degradation of the ionic liquids, whereas aprotic solvents such as DMF significantly exacerbated their degradation. Among the ionic liquids evaluated, it was found that [BMIM]Cl had the greatest stability in ethanol at 150 ℃. The bamboo extraction experiments were then continued with mixtures of [BMIM]Cl in ethanol. The results showed that higher temperatures are necessary to extract lignin and cellulose, with [BMIM]Cl's thermal stability at these temperatures giving it the advantage over [EMIM]Ac. In this system as well it was shown that higher concentrations of ionic liquid facilitated the extraction of more biomass. However, biomass constituents that dissolve into mixtures with lower concentrations of ionic liquid readily precipitate back out of solution when the mixture is returned to room conditions. Along with the results of the studies with [EMIM]Ac, the experiments conducted with [BMIM]Cl show that an increase in pressure results in greater amounts of dissolved biomass holding other conditions constant. The thesis, in summary, presents for the first time (a) the use of ionic liquids as a minor component in organic solvents as a potential biomass processing media, (b) the thermal stability of ionic liquids in a cosolvents at high pressures and temperatures, and (c) experimental results showing that pressure can enhance the amount that can be extracted from biomass with mixtures of ionic liquids in a cosolvent like ethanol. / Doctor of Philosophy / The purpose of the work detailed in the present thesis is to better understand the effects of mixtures of ionic liquids and traditional solvents on woody biomass. Ionic liquids are organic salts with melting points below 100 ℃, and they possess unique physical and chemical properties that can facilitate the dissolution or extraction of otherwise recalcitrant materials. There is a rapidly growing need for greener and more sustainable methods of processing woody biomass, which consist of primarily cellulose, lignin, and hemicelluloses. Industrial use of these liquids as processing solvents for woody biomass is limited by their relatively high viscosity, cost, and the difficulty of separating dissolved materials back out of solution. One method used to address these limitations is to mix the ionic liquids with other solvents, such as ethanol. The studies detailed in this thesis also seek to understand the effects of temperature and pressure on both the dissolution of woody biomass and on the degradation of the ionic liquids. The studies employ both traditional characterization equipment and a custom-designed view-cell which allowed for observation and characterization at high temperatures and pressures. The first part of the study investigated the dissolution of bamboo with mixtures of the ionic liquid 1-ethyl-3-methylimidazolium acetate, [EMIM]Ac, and ethanol. The effects of changing the temperature, pressure, and solvent composition on the removal of different components of the bamboo were assessed. It was found that temperature played the most significant role in the amount of material extracted, with higher temperatures resulting in the removal of more lignin than cellulose. The concentration of ionic liquid in solution was also important, with higher concentrations resulting in more dissolved biomass. Finally, increasing the pressure resulted in higher amounts of dissolved biomass. The next parts of the study focused on the degradation of the ionic liquids at elevated temperatures. The type of ionic liquids used in this study do not boil or evaporate at high temperatures, but instead break down into constituents that are themselves volatile. The thermal degradation of the ionic liquid used in the initial biomass dissolution experiments was investigated along with a series of similar ionic liquids. Their degradation behavior was assessed both by measuring their mass over time at a single constant temperature, and by heating them at a constant rate until they fully degraded. This behavior was mathematically modeled. The thermal stability of the most promising ionic liquids were then investigated in mixtures with other solvents in the high-pressure experimental cell under the same temperature and pressure conditions used in the biomass dissolution experiments. The ionic liquid found to have the best stability in ethanol in those experiments was 1-butyl-3-methylimidazolium chloride, [BMIM]Cl. Further dissolution experiments were carried out with mixtures of this ionic liquid in ethanol. These experiments took the insights gained from the previous investigations to further clarify the effects of temperature, concentration, and pressure on the dissolution of bamboo in mixtures of ionic liquid and ethanol. It was again shown that higher temperatures are necessary to extract lignin and cellulose. It was also shown that higher concentrations of ionic liquid facilitate the extraction of more biomass. However, it was also shown that biomass dissolved into mixtures with lower concentrations of ionic liquid readily precipitates back out of solution when the mixture is returned to room conditions. Pressure was again shown to have a favorable effect on the amount of material extracted.

One of the most significant challenges faced when modeling mass transfer from contaminant source zones is uncertainty regarding parameter estimates. These rate parameters are of particular importance because they control the connectivity between a simulated contaminant source zone and the aqueous phase. Where direct observation has fallen short, this study attempts to interpret field data using an inverse modeling technique for the purpose of constraining mass transfer processes which are poorly understood at the field scale. Inverse modeling was applied to evaluate parameters in rate-limited models for mass transfer. Two processes were analyzed: (i) desorption of hydrophobic contaminants and (ii) multicomponent Non-Aqueous Phase Liquid (NAPL) dissolution. Desorption was investigated using data obtained from elution experiments conducted with weathered sediment contaminated with 2,4,6 trinitrotoluene (TNT) (Sellm and Iskandar, 1994). Transport modeling was performed with four alternative source models, but predictive error was minimized by two first-order models which represented sorption/desorption using a Freundlich isotherm. The results suggest that first-order/Freundlich models can reproduce dynamic desorption attributed to high-and-low relative energy sorption sites. However, additional experimentation with the inversion method suggests that mass constraints are required in order to appropriately determine mass transfer coefficients and sorption parameters. The final portion of this research focused on rate-limited mass transfer from multicomponent NAPLs to the aqueous phase. Previous work has been limited to bench and intermediate scale findings which have been shown to inadequately translate to field conditions. Two studies were conducted in which numerical modeling was used to reproduce dissolution from multicomponent NAPL sources. In the first study, a model was generated to reproduce dissolution of chloroform (TCM), trichloroethylene (TCE) and tetrachloroethylene (PCE) observed during an emplaced-source field experiment conducted within a flow cell (Broholm et al., 1999). In the second study, a methodology was developed for analyzing benzene, toluene, ethylbenzene and xylene (BTEX) data during a field-scale mass transfer test conducted within a vertically-smeared source zone (Kavanaugh, 2010). The findings suggest that the inversion technique, when provided appropriate characterization of site and source parameters and when given appropriate dataset resolution, represents a viable method for parameter determination. Furthermore, the findings of this research suggest that inversion-based modeling provides an innovative predictive method for determining mass transfer parameters for multicomponent mixtures at the field scale. / Ph. D.

Rotational-translational decoupling, a phenomenon commonly observed in supercooled liquids, has been a topic of great interest. Despite its prevalence, the underlying cause of this phenomenon, often attributed to dynamic heterogeneity, has not been conclusively elucidated. This thesis investigates and evaluates how dynamic heterogeneity may lead to this decoupling using simultaneous single-molecule rotational and translational measurements. In the experimental study, single molecule fluorescence imaging experiments are performed on the ideal probe N,N’-dipentyl-3,4,9,10-perylenedicarboximide in high molecular weight polystyrene near its glass transition temperature. A novel trajectory linking method based on hierarchical clustering is developed to facilitate single molecule tracking even in imaging data where specific molecules cannot be observed visually for a substantial number of frames. This linking algorithm then allows molecules to be localized over full movies, such that rotational and translational measurements can be compared over comparable timespans. The investigation of translational dynamics using such long trajectories, which was not previously achieved, reveals that both rotational-translational decoupling and translational enhancement persist on the single molecule level, supporting the hypothesis that temporally heterogeneous dynamics experienced by the probe molecules is a contributing factor in observed rotational-translational breakdown in both ensemble and single molecule studies. A tendency towards dynamical convergence between subgroups with fast and slow dynamics is observed, demonstrating temporal heterogeneity at the single molecule level. In comparison to rotational dynamics, translational dynamics was discovered to have a longer lifetime. Other key observations facilitated by the linked trajectory analysis include that apparent diffusion coefficient of probe molecules decreases with longer observation time, a finding inconsistent with normal diffusive behavior. To investigate the origin of this anomalous slowing in single molecule studies existing alongside the observed overall enhancement in translational motion, temporally heterogeneous models with multiple types of correlation were studied via simulations. The results emphasize the critical role that bias in translational and rotational measurements can play when investigating and observing dynamic heterogeneity, as nearly all models including dynamic heterogeneity show increasing diffusion coefficient with increasing number of dynamic environments explored. Strikingly, translational enhancement is evident in single molecule translational simulations even when slow dynamics are reinforced via positive correlation in the models. A comparison of the diffusion coefficient evolution between simulations and experiments reveals that the sub-diffusive continuous time random walk model is the most plausible candidate to account for the set of observations seen in experiment.

A literature survey was performed to evaluate the state-of-the-art membrane systems for CO₂/CH₄ separation which is critical in the natural gas industry. The systems that were reviewed included zeolite, carbon, polymeric, mixed matrix, amorphous silica, and supported ionic liquid membranes. Supported ionic liquid CO₂/CH₄ selective membranes were synthesized in our laboratory by applying room temperature ionic liquids (RTILs) to porous inorganic α-alumina supports. The supported ionic liquid membranes (SILMs) displayed CO₂ permeance of 1x10⁻⁹ to 3x10⁻⁸ mol m⁻² s⁻¹ Pa⁻¹ and CO₂/CH₄ selectivity of up to 50 which is comparable with the current polymeric separation systems. It is concluded that, although the RTIL membranes showed good CO₂/CH₄ selectivity, the CO₂ permeance was too low for industrial applications. A new type of SILM was prepared by dissolving 1-aminopyridinium iodide which contained amine functionality in other ionic liquids which improved the CO₂ permeance and selectivity of these membranes. The H₂ gas separation is an important process because it has many industrial applications in petroleum processing and chemical synthesis. Amorphous silica membranes for H₂ separation were prepared on hollow fiber (HF) inorganic supports using chemical vapor deposition (CVD) of tetraethyl orthosilicate (TEOS). These membranes exhibited good H₂ permeance on the order of 10⁻⁷ mol m⁻² s⁻¹ Pa⁻¹ together with H₂/CO₂ selectivity of over 100. The separation was achieved using a new hybrid intermediate layer that was developed by depositing a mesoporous silica layer on top of γ-alumina. / Master of Science

A study of procedures and techniques of measuring dielectric constant and dipole moment of liquids.

The heterogeneous dynamics exhibited by supercooled liquids near the glass transition temperature (𝑇_𝑔) has been a topic of much research over the past several decades. In particular, the advent of single molecule (𝖲𝖬) methods has permitted great insight into the extent of both spatial and temporal heterogeneities in these systems, information which is either difficult or impossible to access via ensemble approaches. Despite this, the related phenomenon of rotational-translation decoupling, whereby the translational motion observed in supercooled systems is enhanced relative to Debye-Stokes-Einstein predictions, is difficult to study with 𝖲𝖬 approaches. This is due to the very low localization uncertainty required to accurately report the extremely slow translational motion in supercooled systems near 𝑇_𝑔. In this thesis, a new approach for quantifying rotational dynamics in supercooled liquids is introduced which leverages fluorescence intensity fluctuations due to out-of-plane fluorophore rotations. Unlike linear dichroism (LD) measurements, the most common experiment used to access rotational dynamics, this technique does not require a polarizing optical element, thus improving localization precision in the acquired images. This intensity fluctuation-based approach is shown to report comparable rotational correlation timescales (𝝉_𝘤) and information on dynamic heterogeneity to that typically extracted via LD measurements. On a probe-by-probe basis, rotational correlation times obtained from simultaneous measurement of LD (𝝉_𝘤,𝘓𝘋) and intensity fluctuations (𝝉_𝘤,𝘐 ) are found to be only moderately well-correlated. We postulate that this is a consequence of dynamic heterogeneity due to temporal dynamic exchange, the process in which a probe (and its surroundings) undergoes sudden changes in dynamics. This hypothesis is explored through simulations, which reveal that the Pearson R correlation coefficients associated comparing log 𝝉_𝘤,𝘐 and log 𝝉_𝘤,𝘓𝘋 increases as the time between dynamic exchange increases. The information obtained from such simulations is then used to estimate the exchange timescales from experimental data. When examined in concert with experimentally measured degrees of relaxation non-exponentiality - generally considered a metric of heterogeneity in an interrogated supercooled liquid – this permits access to previously inaccessible information regarding the breadth of the distribution of underlying timescales experienced by these supercooled systems. In addition to this work focused on rotational dynamics, we also aim to further clarify information contained in 𝖲𝖬 experiments characterizing translational dynamics, towards the goal of full understanding of rotational-translational decoupling. Here, two widefield fluorescence imaging setups are optimized to minimize localization uncertainty, and differences in how localization uncertainties manifest in perceived translational motion near 𝑇_𝑔 are examined. The setup with greater localization uncertainty reports faster translational dynamics compared to the other optical setup, suggesting significant influence of the localization noise floor on perceived dynamics and highlighting the importance of maximizing the signal to noise ratio of 𝖲𝖬 experiments aiming to study the underlying cause of rotational-translational decoupling.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第24925号 / エネ博第467号 / 新制||エネ||87(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 萩原 理加, 教授 佐川 尚, 教授 野平 俊之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

This dissertation aims to investigate and correlate structure, dynamics and transport properties of several novel soft materials systems using multiple Nuclear Magnetic Resonance (NMR) methodologies, including solid-state NMR (SSNMR), diffusometry, and imaging, and with the help of X-ray scattering. First, we report the investigation of structure and dynamics of three polymeric membranes: hydroxyalkyl-containing imidazolium homopolymers, poly(arylene ether sulfone) segmented copolymers, and disulfonated poly(arylene ether sulfone) random copolymers using a wide array of SSNMR techniques, including: 1) ¹³C cross-polarization magic angle spinning (CPMAS) with varying cross-polarization (CP) contact time, 2) ¹³C single-pulse magic angle spinning (MAS) with varying delay time, 3) ²³Na single-pulse MAS, 4) two dimensional phaseadjusted spinning sideband (2D PASS), 5) proton spin−lattice relaxation (T₁), 6) rotating frame spin−lattice relaxation (T₁ρ), and 7) center-band-only detection of exchange (CODEX). These various types of SSNMR spectroscopic methods provide a wealth of structural and dynamic information over a wide range of time scales from a few nanoseconds to seconds. We further present a picture of rich structural and transport behaviors in supramolecular assemblies formed by amphiphilic wedge molecules using a combination of ²³Na solid-state NMR, ¹H/²H PFG NMR diffusion, relaxation and grazing-incidence small-angle X-ray scattering. Our results show that the liquid crystalline domains in these materials undergo a transition from columnar to bicontinuous cubic phases with a simple increase in humidity, while the amorphous domain boundaries consist of individual wedge molecules with a significant fraction (~ 10%) of total wedge molecules. Multiple-component diffusion of both wedges and water further confirms the structural and dynamic heterogeneity, with the bicontinous cubic phase being able to facilitate much faster water and ion transport than the columnar phase. We then develop a quantitative approach to probe the migration of two novel “theranostic” polymeric agents (combining “therapeutic” and “diagnostic” functions) into bulk hydrogels using two distinct time-resolved magnetic resonance imaging (MRI) methods. To the best of our knowledge, this is the first work that combines time-resolved MRI experiments to reliably quantify diffusivity of paramagnetic and superparamagnetic nanoparticles in bulk biological media. Our results agree closely with those obtained from fluorescence techniques, yet the capability of our approach allows the analysis of actual nanoparticles diffusion through biogels on mm to cm scales during a range of time periods. Finally, we employ a combination of NMR techniques to obtain a comprehensive understanding of ion clustering and transport behaviors of ionic liquids inside the benchmark ionic polymer Nafion. Spin relaxation shows that anion relaxation is more influenced by the fixed sulfonate groups than cation relaxation. 2D ¹H-¹⁹F heteronuclear Overhauser effect spectroscopy (HOESY) and 1D ¹⁹F¹⁹F selective nuclear Overhauser effect (NOE) spectroscopy confirm our assumption of the formation of ion clusters at low water content in the ionomer. While we observe non-restricted diffusion behavior for cations, anion diffusion is strongly restricted both between domain boundaries and within domains in the absence of water. The restricted anion diffusion can serve as a reliable probe for detailed multiscale structures of the ionomer. / Ph. D.