This thesis focuses on the development of new compounds or new processes that are more environmentally friendly and economical than those currently in use. The decomposition of hydrazine, a well established liquid rocket fuel for both the aerospace and defense industries, to the product ammonia is studied. Control of this reaction will allow hydrazine to be used as a propellant for both chemical and electric propulsion. From this a dual stage thruster will be developed that will be more efficient than current systems decreasing the amount of propellant needed and allowing for either a larger mission payload or a longer duration of individual missions. Hydrazine, while beneficial and well established, is also highly toxic, so other work in this thesis focuses on the synthesis of the novel molecule 1,1-dimethyl-2-[2-azidoethyl]hydrazine or DMAEH and its hydrazone intermediate 1,1-dimethyl-2-[2-azidoethyl]hydrazone or De-DMAEH as less toxic hydrazine replacements. Novel "switchable" ionic liquids have been investigated in this research. These are solvents that can change from molecular liquids to ionic liquids and back, simply with the addition or removal of CO₂ from the system. They can be used for a variety of applications, including as solvents for a reaction and separation system. Due to the recyclable nature of these solvents, waste is decreased making their development and implementation both environmentally and economically beneficial. Finally, the grafting reaction of vinyl silanes onto a hydrocarbon backbone is investigated. Fundamental work is being performed to study the graft distribution, selectivity and mechanism by which this reaction occurs. A more thorough understanding of how this reaction proceeds will allow for the development of a more efficient industrial process.

Cross-linked polyethylene has higher upper use temperature than normal polyethylene and is used as an insulating material for electricity carrying cables and hot water pipes. The most common method of inducing crosslinks is by reaction with silanes. After incorporation of silanes into polyethylene and upon hydrolysis with ambient moisture or with hot water, Si-O-Si crosslinks are formed between the various linear polyethylene chains. Industrially, this reaction is performed routinely. However, the efficiency of this reaction with respect to the silane is low and control of product distribution is difficult. A precise fundamental understanding is necessary to be able to manipulate the reactions and thus, allow for the facile processing of the polymers. Hydrocarbon models of polymers - heptane, dodecane - are being used to study this reaction in the laboratory. For the reaction, vinyltrimethoxysilane is used as the grafting agent along with di-tert-butyl peroxide as the radical initiator. MALDI, a mass spectrometric technique is used for the analysis of the product distribution after work-up. Advanced NMR techniques (COSY, HSQC, DEPT, APT, HMBC) are being conducted on the grafted hydrocarbon compounds to gain an in-depth understanding of the mechanism and regiochemistry of the grafting reaction. Scalable and cost effective methods to capture CO2 are important to counterbalance some of the global impact of the combustion of fossil fuels on climate change. The main options available now include absorption, adsorption and membrane technology. Amines, especially monoethanolamine, have been the most commercialized technology. However, it is not without disadvantages. House et al have investigated the energy penalty involved in the post-combustion CO2 capture and storage from coal-fired power plants and found that 15-20% reduction in the overall electricity usage is necessary to offset the penalty from capturing and storing 80% of United States coal fleet's CO2 emssions1. Novel non-aqueous amine solvents, developed by the Eckert Liotta group, react with CO2 to form ionic liquids. The ionic liquids readily desorb CO2 upon heating, regenerating the reactive amines and this cycle can be carried out multiple times. An iterative procedure is being adopted to develop amine solvents for CO2 capture. Thermodynamic information like reversal temperature and boiling point of the solvents are collected; they are then used to formulate structure property relationships which allow for new molecules to be engineered. On reaction with CO2, there is a sharp increase in viscosity which is unfavorable from a processing standpoint. Many approaches to mitigate and control viscosity are being studied as well. 1House et al, Energy Environ Sci, 2009, 2, 193-205

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The research projects presented in this thesis are mainly focused toward green chemistry and engineering: developing innovative strategies to minimize waste, improve process efficiency and reduce energy consumption. Specifically, the work was centered on the design and applications of green solvents and processes for the sustainable production of pharmaceuticals. The first project was focused on the use of CO₂ to enhance Suzuki coupling reactions of substrates containing unprotected primary amines. This work established that exceptionally challenging substrates like halogenated amino pyridines (i.e. 4-amino-2-bromopyridine and 4-amino-2-chloropyridine) are suitable substrates for Suzuki coupling reactions under standard conditions using CO₂ pressures, without the need for protection/deprotection steps which are traditionally considered to be necessary for these reactions to proceed cleanly. The second project explored the use of water at elevated temperatures (WET) for the sustainable and selective removal of protecting groups. The favorable changes that occur in the physiochemical properties (i.e. density, dielectric constant and ionization constant) of water at elevated temperatures and pressures make it an attractive solvent for the development of sustainable, environmentally green processes for the removal of protecting groups. The water-mediated selective removal of protecting groups such as N-Boc, N-Acetyl and O-Acetyl from a range of organic model compounds was successfully achieved by tuning the temperature (125 to 275°C) or properties of water. The third project investigated the use of Organic-Aqueous Tunable Solvents (OATS) for the rhodium catalyzed hydroformylation of p-methylstyrene. This enables the reactions to be carried out efficiently under homogeneous conditions, followed by a carbon dioxide (CO₂) induced heterogeneous separation. Modest pressures of CO₂ induced the aqueous-rich phase (containing the catalyst) to separate from the organic-rich phase (containing the reactant), thus enabled an easy separation and recycling of catalyst. The use of Al(OtBu)₃ as a potent catalyst toward continuous Meerwein-Ponndorf-Verley (MPV) reductions was established in the fourth project. The MPV reduction of model compounds like benzaldehyde and acetophenone to their corresponding alcohols was investigated in continuous mode as a function of temperature and catalyst loading. These results established a roadmap for the pharmaceutical industry to document the implementation of continuous flow processes in their manufacturing operations.

Monitored natural attenuation has been particularly used at sites where petroleum hydrocarbons and chlorinated solvents have contaminated soil and groundwater. One of the important aspects of the methodology that has been recognized recently is that the mass removal rates, the most important parameter to determine effectiveness of the methodology, is controlled by the groundwater flow regime and the aquifer heterogeneity. Considering this recognition, the primary objective of this study is to quantitatively describe the relationship between the natural attenuation rates and aquifer heterogeneity using numerical simulation techniques. To represent different levels of aquifer heterogeneity, the hydraulic conductivity distribution (ln K) is statistically simulated with the numerical algorithm, Turning Bands Random Field Generator, by changing the statistical parameters, Coefficient of Variation (CV) and correlation length (h) and Visual MODFLOW and RT3D software programs are used for the simulation of groundwater flow and chlorinated solvent transport. Simulation results showed that degradation rates and the shape of the contaminant plumes show variations for different heterogeneity levels. Increasing CV resulted in the decrease in the transport of the plume and shrinkage in the areal extend. On the other hand, &ldquo / h&rdquo / determined the shape and the size of the plume through its affect on mechanical dispersion. For a given &ldquo / h&rdquo / , degradation rates increased with increasing CV, but change in &ldquo / h&rdquo / did not show a regular trend. Such findings are expected to be beneficial when assessing the effectiveness of natural attenuation process for a selected site during the feasibility studies without need for detailed site characterization.

Progress in the microelectronics industry is driven by smaller and faster transistors. As feature sizes in integrated circuits become smaller and liquid chemical waste becomes an even greater environmental concern, gas expanded liquids (GXLs) may provide a possible solution to future device fabrication limitations relative to the use of liquids. The properties of GXLs such as surface tension can be tuned by the inclusion of high pressure gases; thereby, the reduced surface tension will allow penetration of cleaning solutions into small features on the nanometer scale. In addition, the inclusion of the gas decreases the amount of liquid necessary for the photoresist and etch residue removal processes. This thesis explores the role of CO2-based GXLs for photoresist and etch residue removal. The gas used for expansion is CO2 while the liquid used is methanol. The cosolvent serving as the removal agent is tetramethyl ammonium hydroxide (TMAH) which upon reacting with CO2 becomes predominantly tetramethyl ammonium bicarbonate (TMAB).

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 6 uppsatser.

19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 1948" Jamie Marie Rintelman. 12/19/2004. Report is also available in paper and microfiche from NTIS.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

A técnica de microencapsulamento consiste em englobar um núcleo com o material que se deseja proteger com uma casca sólida que tem a finalidade de proteger o núcleo. A técnica de evaporação de solvente consiste em realizar duas emulsões, contendo o núcleo que se deseja encapsular, o polímero que formará a cápsula dissolvido em solvente e um meio de dispersão. Para o processo, a modificação de parâmetros e condições de processo são capazes de aumentar a eficiência do microencapsulamento. Foram produzidas microcápsulas de poliestireno contendo água deionizada com o objetivo de analisar o efeito da relação núcleo cápsula, temperatura de evaporação, presença de cloreto de sódio e surfactante na eficiência do processo de microencapsulamento, quando comparados a uma amostra padrão. Adicionalmente, as amostras foram caracterizadas por microscopia eletrônica de varredura (MEV) e análise termogravimétrica (TG). Foi encontrado que a relação núcleo: cápsula ideal para a produção de microcápsulas é de 2:1, com eficiência de 61,47 %. A análise termogravimétrica indicou também que a relação 2:1 apresentava melhor eficiência pois continha uma maior quantidade de material do núcleo. As imagens de MEV mostraram que a microcápsula formada possui superfície lisa. A adição de tensoativo e a redução da temperatura de evaporação aumentaram a eficiência para 76,83 % e 79,25 % respectivamente. / The microencapsulation technic consist in envelop a core with the material to protect by a solid shell that protects the core for the external environment.The solvent evaporation techtnic consist into two emulsion, the core that wants to be encapsulated, the polimers for the shell solved into a organic solvent and a dispesion media. For the process, the modification of process parameters are able to improve the yeld of the microencapsulation. It was produced polystyrene microcapsules with deionized water to evaluate the effect of core: shell ratio, evaporation temperature, the presence of sodium chloride and the surfactant in the efficiency microencapsulation process, when compared to a standard sample. Additionally, samples were characterized by scanning electron microscopy (SEM) and thermal gravimetric analysis (TG). It was found that the ideal core:shell ratio for the production of microcapsules is 2: 1, with 61.47% of yelding. Thermogravimetric analysis also indicated that the 2:1 ratio had better efficiency since it contained a larger amount of the core material. The SEM images showed that the formed microcapsule has smooth surface. The addition of surfactant and reducing the evaporation temperature increased the efficiency of 76.83% and 79.25% respectively.