Rising greenhouse gas (GHG) emissions is a major cause of concern today. The primary source of energy all over the globe is fossil fuels, a non-renewable source of energy that is expected to get exhausted in the next 60-100 years. Damage to environment cannot be easily reversed but the initial steps are to reduce the damage done.  Other alternative cleaner sources of energy are being looked into as viable options to replace fossil fuels. The objective of this study is to identify options for using hydrogen as an energy carrier in the future with a major focus on the transportation sector. This project is limited to theoretical study looking into the options for hydrogen storage and distribution. Gaseous and liquid hydrogen storage have been looked in to thoroughly and are far from meeting Department of Energy, USA, (DOE) ultimate targets for automobile fleets, hence a shift to other storage options is imminent. Metal hydride storage is believed to be the upcoming technology as the mid-term solution to storage issues and hence is given a lot of attention in this project. On-board storage in metal hydrides is studied and it can be concluded that no metal hydride known to us today is capable of satisfying the DOE ultimate targets. Finally, the study ends with options accessible to AGA to purchase hydrogen within Sweden and how they can be cleaned to meet the fuel cell gas purity requirements.

In this project, the effect of solution thermal and structural history on nucleation was investigated. Many researchers have shown that temperature and duration of pretreatment has an influence on induction time, polymorphic outcome and metastable zone width. Here, solution of tolbutamide in 1-propanol was first prepared with same conditions, to “standardize” and control the initial solution history. Next, pretreatment of varied duration and temperature was applied to introduce different solution history. Then, nucleation began in 9℃, and induction time and polymorphic outcome were measured. Two batches of 30 isolated nucleation experiments each, were done per set of conditions. The results showed an impact on induction time and polymorphic outcome. However, this change cannot be clearly correlated with the conditions of pretreatment. Furthermore, the deviation between series of experiments that were performed under the same set of conditions, showed that the parameters affecting induction time and polymorphism were not controlled sufficiently to reach a safe conclusion. Moreover, the effect of solution filtration right before nucleation was investigated. This filtration step decreased experimental induction time from 160 minutes to less than 5. It is possible that this filtration step removed the solution’s structural memory, which accelerated nucleation. However, the effect of evaporation on concentration for example, or other parameters was not investigated. Furthermore, the effect of using filtration with 0.1 and 0.2 μm filters was examined. It was found that using 0.1 filter results in decreased median induction time by a factor of 4. Finally, filtration before standardization resulted in a 1.5% increase in concentration compared to solution that was not filtered. Filtration with 0.1 μm filter before standardization decreased median induction time by a factor of 4, as compared to using a 0.2 μm filter. / Detta projekt har undersökt effekten av en lösnings förhistoria vad gäller temperatur och struktur på kristallkärnbildning. Tidigare forskning har visat att både temperaturen och tiden för en lösnings förbehandling har inflytande på induktionstid, kärnbildande polymorf och metastabil zonbredd. I detta projekt förbereddes först lösningar av tolbutamid i 1-propanol vid identiska förhållanden, för att standardisera och kontrollera lösningens förhistoria. Därefter varierades längden och temperaturen för förbehandlingen för att introducera olika förhistoria. Kärnbildningsexperiment utfördes vid 9°C varvid induktionstid och kärnbildande polymorf noterades. Två batcher med 30 lösningar vardera kristalliserades för varje uppsättning experimentella förhållanden.  Resultaten påvisar ett inflytande på induktionstid och kärnbildande polymorf, vilka dock inte på ett tydligt sätt korrelerar med förbehandlingsparametrarna. Vidare visar spridningen mellan identiska experiment att parametrar som styr induktionstid och polymorfi inte kontrollerats tillräckligt väl för att dra tydliga slutsatser. Effekten av filtrering av lösningar precis innan kärnbildning har också undersökts. Filtrering ledde till en förkortning av experimentellt uppmätta induktionstider från 160 min till mindre än 5 min. Det är möjligt att filtreringen raderade lösningens strukturella ”minne”, vilket lett till en snabbare kärnbildning. Effekten av förångning av lösningsmedlet i samband med filtreringen på koncentrationen har dock inte undersökts. Skillnaden i effekt mellan användning av 0.1 μm och 0.2 μm filter undersökts. Användning av 0.1 μm filter resulterade i ett minskat medianvärde för induktionstid motsvarande en faktor 4. Ett filtreringssteg innan standardiseringssteget resulterade i en 1.5% minskning i koncentration jämfört med icke-filtrerade lösningar.

The pursuit of reliable and high-performance batteries has fueled extensive research into new battery chemistries and materials, aiming to enhance the current lithium-ion battery technologies in terms of energy density and safety. Among the potential advancements, solid-state batteries (SSBs) have captured significant attention as the next-generation energy storage technology. One key factor contributing to their appeal is the utilization of solid-state electrolytes (SSEs) with a wide electrochemical stability window (ESW), making SSBs compatible with high-voltage cathodes. The energy density of SSBs can be further improved by employing the “holy-grail” anode, Li-metal, which boasts the lowest working voltage (-3.04 V vs. Li+/Li) and an ultrahigh theoretical capacity (3860 mAh g−1). Consequently, these batteries are referred to as lithium metal batteries (LMBs). However, realizing the full potential of LMBs presents formidable challenge, including the low ionic conductivity of current SSEs, large interfacial resistance between SSE and electrodes, uncontrollable interfacial reactions, and the growth of Li dendrites.  Typically, SSEs can be categorized into three types. Among these, solid composite electrolytes (SCEs) are considered the most promising choice for solid-state LMBs due to their combination of high ionic conductivity and excellent mechanical strength from inorganic solid electrolytes (ISEs) and the flexibility and good interface compatibility provided by solid polymer electrolytes (SPEs). Polymeric ionic liquids (PolyILs), which contain both ionic liquid-like moieties and polymer frameworks, have emerged as highly attractive alternatives to traditional polymers in SCEs.  The overall objective of this thesis was to develop PolyIL-based SCEs with enhanced ionic conductivity, wide ESW, high Li+ transference number, and reduced electrodes/electrolyte interface resistance. The main progress achieved in this thesis is as follows: 1. We selected three F-based Li-salts to prepare SPEs using poly(ethylene oxide) and polyimide. The investigation focused on assessing the impact of molecular size, F content, and chemical structures (F-connecting bonds) of these Li-salts. Additionally, we aimed to uncover the formation process of LiF in the solid electrolyte interphase (SEI). The result revealed that the F-connecting bond plays a more significant role than the molecular size and F element content, resulting in slightly better cell performance using LiPFSI compared to LiTFSI and substantially better performance compared to LiFSI. The preferential breakage of bonds in LiPFSI was found to be related to its position to Li anode. Consequently, we proposed the LiPFSI reduction mechanism based on these findings. 2. Using the template method, we synthesized a monolayer SCE with enhanced Li+ transference number and high ionic conductivity. In this study, boron nitride (BN) nanosheets with a high specific surface area and richly porous structure were employed as inert inorganic filler. These BN nanosheets played a crucial role in homogenizing the Li+ flux and facilitating the Li+ transmission to suppress Li dendrite growth. When integrated into a LiFePO4//Li cell with the optimized SCE, the assembled battery demonstrated remarkable cycling performance.  3. A monolayer GSCE with multifunctionality was synthesized via a natural sedimentation and subsequent UV-curing polymerization technique. This innovative method capitalizes on intrinsic gravity, allowing for the integration of multiple functions within a single layer, thereby eliminating the additional interlayer resistance. The developed GSCE provides an optimum Li+ transportation path and enhanced Li+ transference number, leading to an enhanced ionic conductivity and a long cycle life of Li//Li cells and SSLMBs. Compared with the monolayer uniform SCEs, the gradient structure also alleviates the uncoordinated thermal expansion between fillers and PolyIL, avoiding increased stress during the cycle and battery capacity fade.

The self-assembly of isotropic and anisotropic colloidal particles into higher-ordered structures has been of great interest recently due to the promise of creating metamaterials with novel macroscopic properties. The physicochemical properties of these metamaterials can be tailored to achieve composites with tunable functionalities. The formation of these metamaterials can be used as a pathway to emulating advanced biological systems. In particular, synthetically mimicking the surface of a moth’s eye, which consists of arrays of ellipsoidal protuberances, can be used as a strategy for fabricating antireflective coatings. To enable this technology, it is necessary to design a synthesis scheme that produces micron-sized composite particles with tunable refractive index. In the future, the resulting composite microparticles can then undergo geometric and spatial modifications to form self-assemblies that have unique macroscopic material properties. This research work delineates a strategy of developing microparticles with a hybrid configuration that constitutes an inorganic and an organic part. The inorganic part comprises ~30 nm diameter titania (TiO2) nanoparticles, which are embedded within an organic polymer particle comprised of diethyl methylene malonate polymer [p(DEMM)]. Anionic polymerization is modified to controllably incorporate TiO2 nanoparticles into the polymer matrix. A design of experiments was identified and carried out to identify the major process variables that influence the final particle size. In particular, since DEMM polymerization may be initiated entirely by the presence of hydroxyl anions, pH was found to control the final overall particle diameter between 300 nm and 1 micrometer. The overall inorganic particle loading can be readily modified and is confirmed by thermogravimetric analysis, allowing for the desired macroscopic refractive index to be controlled. Light scattering, scanning electron microscopy and zeta potential analysis reveals that the colloidal stability of the hybrid microparticles is dependent on the ligand coating the inorganic constituent. In addition, this synthetic scheme is applied to different inorganic constituents that have interesting functionalities, such as fluorescent CdTe quantum dots, in order to show the methods versatility method to produce composite particles for a wide spectrum of applications. These initial investigations provide a the synthetic groundwork to evaluating the coating properties of the microparticles and their self-assembly into novel materials in the future.

The global market for waterborne coatings will continue to grow because alternative solventborne coatings emit environmentally hazardous volatile organic compounds (VOCs). However, most waterborne coatings are softer than solventborne crosslinked thermoset coatings because they feature thermoplastic polymer dispersions. To overcome these challenges, in this thesis we suggest a novel crosslinkable aqueous dispersion system that incorporates epoxy and amine particles into poly(methyl methacrylate) (PMMA); the particles will react when water (the solvent) evaporates, offering a potential one-component (1K) reactive system. Emulsion polymerization was used to synthesize the particles with the help of surfactants. Epoxy and amine particles were successfully incorporated during the synthesis of PMMA and formed a two-component (2K) aqueous dispersion. In this process, a non-ionic surfactant, Triton X405 (TX405), was used to prevent interactions with the amine particles. Nuclear magnetic resonance (NMR) was used to determine the actual incorporation ratios of epoxy and amine and we found an epoxy incorporation plateau. Dynamic light scattering (DLS) was used to determine the particle size distributions and a uniform distribution was observed. The pendulum test and the pencil test were used for coating hardness, which surpassed currently marketed waterborne coatings. The resulting aqueous dispersions could be cured under facile conditions, i.e., in air and at low temperatures. An increase in Tg was observed after crosslinking. Different mechanical properties were observed when the coatings were cured at different temperatures, 25°C, 70°C, and 100°C. These results suggest that we have successfully formed crosslinked coatings that contain our epoxy and amine incorporated particles, with mechanical properties comparable to the traditional solventborne coatings.

The demand for alternative secondary batteries to lithium-ion batteries (LIBs) grows. Sodium-ion batteries (SIBs) have been studied for many years and could replace LIBsfor some application. Metallic anodes for both LIBs and SIBs are interesting due totheir high energy densities. Several aspects such as reactivity, stability and depositionmorphology must be properly addressed before metallic Na could be considered apossible anode material. This study aims to evaluate deposition of Na on Alelectrodes using fundamental electrochemical theories. Na deposition was studiedusing pouch cells and sodium triflate (NaOTf) in dimethyl glycol ether (diglyme) aselectrolyte. Galvanostatic deposition using different current densities, electrolyteconcentrations and potential pulses prior to galvanostatic deposition were tested. Theelectrochemical methods used in this study were galvanostatic deposition andchronoamperometry. The morphology of deposited Na was analyzed with ex-situscanning electron microscopy (SEM). A decrease of the size of deposited Na islandswas observed for both increasing current density and decreasing electrolyteconcentration. Fluctuations and poor stability in the deposition potential wereobtained when decreasing the electrolyte concentration under 0.5 M and also whenincreasing the current density over 1 mA cm-2. The most homogeneous depositionwas obtained with a 1030 ms potential pulse amplitude (-3 V vs. Na+/Na) prior togalvanostatic deposition (1 mA cm-2, 0.5 mAh cm-2) using 0.1 M NaOTf in diglyme aselectrolyte. Reproducibility was a major issue in this study and further investigation ofseveral parameters is needed.

The past few years have seen an upsurge in the use of renewable biomass as a source of energy due to growing concerns over greenhouse gas emissions caused by the combustion of fossil fuels and the need for energy independence due to depleting fossil fuel resources. Although coal will continue to be a major source of energy for many years, there is still great interest in replacing part of the coal used in energy generation with renewable biomass. Combustion converts inherent chemical energy of carbonaceous feedstock to only thermal energy. On the other hand, partial oxidation processes like gasification convert chemical energy into thermal energy as well as synthesis gas which can be easily stored or transported using existing infrastructure for downstream chemical conversion to higher value specialty chemicals as well as production of heat, hydrogen, and power. Devolatilization or pyrolysis plays an important role during gasification and is considered to be the starting point for all heterogeneous gasification reactions. Pyrolysis kinetic modeling is, therefore, an important step in analyzing interactions between blended feedstocks. The thermal evolution profiles of different coal-biomass blends were investigated at various heating rates using thermogravimetric analysis. Using MATLAB, complex models for devolatilization of the blends were solved for obtaining and predicting the global kinetic parameters. Parallel first order reactions model, distributed activation energy model and matrix inversion algorithm were utilized and compared for this purpose. Using these global kinetic parameters, devolatilization rates of unknown fuel blends gasified at unknown heating rates can be accurately predicted using the matrix inversion method. A unique laboratory scale auto-thermal moving bed gasifier was also designed and constructed for studying the thermochemical conversion of coal-biomass blends. The effect of varying operating parameters was analyzed for optimizing syngas production. In addition, stable carbon isotope analysis using Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry (GC-C-IRMS) was used for qualitatively and quantitatively measuring individual contributions of coal and biomass feedstocks for generation of carbonaceous gases during gasification. The predictive models utilized and experimental data obtained via these methods can provide valuable information for analyzing synergistic interactions between feedstocks and also for process modeling and optimization.

As competition for fossil fuels accelerates, alternative sources of chemicals, fuels, and energy production become more appealing to researchers and the layman. Among the candidates to fill this growing niche is lignocellulosic biomass. Many researchers have examined supply chain design and optimization for biofuel and bioenergy production throughout the years. However, these models often fail to capture the variability and uncertainty inherent to the biomass supply chain. Multiple factors with high degrees of stochasticity can have major impacts on the performance of a biorefinery: weather, biomass quality, feedstock availability, and market demand for products are just a few. To begin to address this issue, a discrete event simulation model has been developed to examine the economic performance of a region specific, multifeedstock biorefinery supply chain. Probability distributions developed for product demand and feedstock supply begin to address the random nature of the supply chain. Model development is discussed in the context of a multidisciplinary framework for biorefinery supply chain design. A case study, sensitivity analysis, and scenario analysis, are utilized to examine the capabilities of the model.

The fossil hydrocarbons are not inexhaustible, and their use is not without impact in our need of energy, fuels and hydrocarbons as building blocks for organic materials. The quest for renewable, environmentally more friendly technologies are in need and woody biomass is a promising candidate, well provided in the boreal parts of the world. To convert the constituents of wood into valuable gaseous products, suitable for the end use required, we need a reliable gasification technology. But to become an industrial application on full scale there are still a few issues to take into account since the presence of contaminants in the process gas will pose several issues, both technical and operational, for instance by corrosion, fouling and catalyst deactivation. Furthermore the downstream applications may have very stringent needs for syngas cleanliness depending on its use. Therefore, the levels of contaminants must be decreased by gas cleanup to fulfil the requirements of the downstream applications. One of the most prominent problems in biomass gasification is the formation of tars – an organic byproduct in the degradation of larger hydrocarbons. So, tar degrading catalysts are needed in order to avoid tar related operational problems such as fouling but also reduced conversion efficiency. Deactivation of catalysts is generally inevitable, but the process may be slowed or even prevented. Catalysts are often very sensitive to poisonous compounds in the process gas, but also to the harsh conditions in the gasifier, risking problems as coke formation and attrition. Alongside with having to be resistant to any physical and chemical damage, the catalyst also needs to have high selectivity and conversion rate, which would result in a more or less tar-free gas. Commercial tar reforming catalysts of today often contain nickel as the active element, but also often display a moderate to rapid deactivation due to the causes mentioned.

Nanotechnology can profoundly benefit our health, environment and everyday life. In order to make this a reality, both technological and theoretical advancements of the nanomaterial synthesis methods are needed. A nanoparticle is one of the fundamental building blocks in nanotechnology and this thesis describes the control of the nucleation, growth and oxidation of titanium particles produced in a pulsed plasma. It will be shown that by controlling the process conditions both the composition (oxidationstate) and size of the particles can be varied. The experimental results are supported by theoretical modeling. If processing conditions are chosen which give a high temperature in the nanoparticle growth environment, oxygen was found to be necessary in order to nucleate the nanoparticles. The two reasons for this are 1: the lower vapor pressure of a titanium oxide cluster compared to a titanium cluster, meaning a lower probability of evaporation, and 2: the ability of a cluster to cool down by ejecting an oxygen atom when an oxygen molecule condenses on its surface. When the oxygen gas flow was slightly increased, the nanoparticle yield and oxidation state increased. A further increase caused a decrease in particle yield which is attributed to a slight oxidation ofthe cathode. By varying the oxygen flow, it was possible to control the oxidation state of the nanoparticles without fully oxidizing the cathode. Pure titanium nanoparticles could not be produced in a high vacuum system because oxygen containing gases such as residual water vapour have a profound influence on nanoparticle yield and composition. In an ultrahigh vacuum system titanium nanoparticles without significantoxygen contamination were produced by reducing the temperature of the growth environment and increasing the pressure of an argon-helium gas mixture within whichthe nanoparticles grew. The dimer formation rate necessary for this is only achievable at higher pressures. After a dimer has formed, it needs to grow by colliding with a titanium atom followed by cooling by collisions with multiple buffer gas atoms. The condensation event heats up the cluster to a temperature much higher than the gas temperature, where it is during a short time susceptible to evaporation. When the clusters’ internal energy has decreased by collisions with the gas to less than the energy required to evaporate a titanium atom, it is temporarily stable until the next condensation event occurs. The temperature difference by which the cluster has to cool down before it is temporarily stable is exactly as many kelvins as the gas temperature.The addition of helium was found to decrease the temperature of the gas, making it possible for nanoparticles of pure titanium to grow. The process window where this is possible was determined and the results presented opens up new possibilities to synthesize particles with a controlled contamination level and deposition rate.The size of the nanoparticles has been controlled by three means. The first is to change the electrical potential around the growth zone, which allows for size (diameter) control in the order of 25 to 75 nm without influencing the oxygen content of the particles. The second means is by increasing the pressure which decreases the ambipolar diffusion rate of the ions resulting in a higher growth material density. By doing this, the particle size can be increased from 50 to 250 nm, however the oxygen content also increases with increasing pressure when this is done in a high vacuum system. The last means of size control was by adding a helium flow to the process where higher flows resulted in smaller nanoparticle sizes. When changing the pressure in high vacuum, the morphology of the nanoparticles could be controlled. At low pressures, highly faceted near spherical particles were produced. Increasing the pressure caused the formation of cubic particles which appear to ‘fracture’ at higher pressures. At the highest pressure investigated, the particles became poly-crystalline with a cauliflower shape and this morphology was attributed to a lowad atom mobility. The ability to control the size, morphology and composition of the nanoparticles determines the success of applying the process to manufacture devices. In related work presented in this thesis it is shown that 150-200 nm molybdenum particles with cauliflower morphology were found to scatter light in which made them useful in photovoltaic applications, and the size of titanium dioxide nanoparticles were found to influence the selectivity of graphene based gas sensors.