In cell biology and chemistry, total internal reflection microscopy (TIRFM) has proven to be a useful technique that allows the probing of cellular processes with high-signal-to-noise ratio imaging. However, samples on solid substrates limit the accessibility to probe processes on extracellular membrane surface closest to the microscope objective. Colloidal crystals provide a porous alternative to the traditional solid substrates. Thin crystals exhibit optical properties similar to that of a fused silica coverslip allowing for TIRFM in the same manner as with a typical coverslip as demonstrated by the observance of Chinese hamster ovary cells with fluorescently labeled receptors on both types of substrates. Accessibility of the cell membrane closest to the substrate and the ability to probe fluorophore orientation information was observed by the binding of TIPP-cy5 to the human delta opioid receptor.

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The objective of this research was to develop high performing polymer modified calcium sulfoaluminate (CSA) cement materials for use in applications requiring superior adhesion characteristics. Little information is available describing interactions of CSA cement containing minor phase tri-calcium aluminate (C3A) with commonly used admixtures. Given the scarcity of information, a basic approach for developing cementitious materials was followed. The basic approach consisted of four tasks: cement design, admixture design, polymer design and testing developed materials. The iterative, time consuming process is necessary for understanding the influence of specific constituent components on overall system behavior. Results from the cement design task suggest calcium sulfate type influences microstructural characteristics and strength development for materials based upon the experimental CSA cement. Results from the admixture design task suggest lithium carbonate and tartaric acid are effective accelerating and retarding admixtures for hydration reactions including reactants yeelimite, calcium sulfate and water. Results from the polymer design task suggest vinyl acetate / ethylene (VAE) dispersible polymer powders (DPP) are compatible with systems containing the experimental CSA cement and other commonly used admixtures. Additionally, results from the polymer design task highlight a method for specifying the ductile behavior of materials containing the experimental CSA cement as majority hydraulic binding agent. Finally, results from the testing of developed materials task suggests adhesion performance for materials containing the experimental CSA cement can be influenced by adjusting the ratio of polymer to hydraulic binding agent in material formulations. Polymer modified CSA cement mortars demonstrated bond strength resulting in substrate failure when cast over porous concrete substrates. Developed mortars demonstrated consistent bonding performance when applied to non-porous substrate materials, metal and glass. Select polymer modified mortars displayed adhesion bond performance such that the glass substrate materials fractured during pull off testing.

Microalgae cultivation has received much research attention in recent decades due to its high photosynthetic productivity and ability to produce biofuel feedstocks as well as high value compounds for the health food, cosmetics, and agriculture markets. Microalgae are conventionally grown in open pond raceways or closed photobioreactors. Due to the high water contents of these cultivation systems, they require large energy inputs for pumping and mixing the dilute culture, as well as concentrating and dewatering the resultant biomass. The energy required to operate these systems is generally greater than the energy contained in the resultant biomass, which precludes their use in sustainable biofuel production. To address this challenge, we designed a novel photobioreactor inspired by higher plants. In this synthetic leaf system, a modified transpiration mechanism is used which delivers water and nutrients to photosynthetic cells that grow as a biofilm on a porous, wicking substrate. Nutrient medium flow through the reactor is driven by evaporation, thereby eliminating the need for a pump. This dissertation outlines the design, construction, operation, and modeling of such a synthetic leaf system for energy positive biofuel production. First, a scaled down synthetic leaf reactor was operated alongside a conventional stirred tank photobioreactor. It was demonstrated that the synthetic leaf system required only 4% the working water volume as the conventional reactor, and showed growth rates as high as four times that of the conventional reactor. However, inefficiencies in the synthetic leaf system were identified and attributed to light and nutrient limitation of growth in the biofilm. To address these issues, a modeling study was performed with the aim of balancing the fluxes of photons and nutrients in the synthetic leaf environment. The vascular nutrient medium transport system was also modeled, enabling calculation of nutrient delivery rates as a function of environmental parameters and material properties of the porous membrane. These models were validated using an experimental setup in which the nutrient delivery rate, growth rate, and photosynthetic yield were measured for single synthetic leaves. The synthetic leaf system was shown to be competitive with existing technologies in terms of biomass productivity, while requiring zero energy for nutrient and gas delivery to the microorganisms. Future studies should focus on utilizing the synthetic leaf system for passive harvesting of secreted products in addition to passive nutrient delivery. / text