Theses and Dissertations at Montana State University (MSU)
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Item Material properties of ureolytically induced calcium carbonate adhesives(Montana State University - Bozeman, College of Engineering, 2023) Anjum, Sobia; Chairperson, Graduate Committee: Robin Gerlach; This is a manuscript style paper that includes co-authored chapters.Polymers used in adhesive applications are often petrochemical-based and release volatile organic compounds (VOCs) during application. These VOCs can accumulate indoors to the detriment of human health. Biopolymers potentially offer a non-toxic and sustainable alternative to synthetic polymers but generally have limited physical stability and low mechanical performance. One of the methods of improving the stability and adhesive performance of biopolymers is the addition of a mineral phase to reinforce biopolymer adhesives. In this work, biomineral-reinforced biopolymer adhesives were produced by ureolytically induced precipitation of calcium carbonate in the presence of guar gum and soy protein. The microbially and enzymatically induced ureolysis was carried out by the ureolytic bacterium, Sporosarcina pasteurii, or by jack bean urease. The resulting adhesives were referred to as ureolytically induced calcium carbonate precipitation (UICP)-reinforced adhesives and specifically microbially and enzymatically induced calcium carbonate (MICP and EICP)- reinforced adhesives. The adhesive strength of these composite adhesives was optimized by varying calcium and cell (or enzyme) concentrations. The adhesive strength of biomineral reinforced guar gum and soy protein biopolymers was up to 2.5 and 6 times higher than the adhesive strength of the biopolymers alone, respectively. The durability of the MICP-reinforced adhesives was tested after varying immersions (24 h and 7 days), relative humidities (50 and 80% RH), and temperatures (-20, 100, and 300?C). The durability of the MICP-reinforced adhesives, upon immersion, was significantly improved compared to biopolymer alone, and maintained their adhesive strength at moderate humidities and from below-freezing to room temperatures after 7- day exposures. To determine the effect of biopolymers on the nanoscale material properties of biomineral aggregates, enzymatically induced calcium carbonate precipitation was induced in the presence of a standard protein, Bovine Serum Albumin (BSA). Nanoindentation and Atomic Force Microscopy show that the moduli of the mineral precipitates were significantly lowered in the presence of BSA. Atomic force microscopy also showed that BSA introduced structural variations and moduli gradation in biominerals. These results demonstrate that the presence of a protein additive, specifically BSA, can alter the nanoscale structure and material properties of calcium carbonate precipitates. Using an organic additive to manipulate microscale material properties of biominerals offers possibilities for advanced control at the microscale and enhanced toughness at the macroscale for engineering applications such as in construction, binder, and adhesive applications.Item Nuclear magnetic resonance studies of biological and biogeochemical processes(Montana State University - Bozeman, College of Engineering, 2013) Vogt, Sarah Jane; Chairperson, Graduate Committee: Joseph D. Seymour; Sarah L. Codd (co-chair); Brandy D. Stewart, Joseph D. Seymour, Brent M. Peyton, and Sarah L. Codd were co-authors of the article, 'Detection of biological uranium reduction' in the journal 'Biotechnology and bioengineering' which is contained within this thesis.; Alexis B. Sanderlin, Joseph D. Seymour, and Sarah L. Codd were co-authors of the article, 'Permeability of a growing biofilm in a porous media fluid flow analyzed by magnetic resonance displacement-relaxation correlations' in the journal 'Biotechnology and bioengineering' which is contained within this thesis.; Hilary T. Fabich was a main author, and Matthew L. Sherick, Joseph D. Seymour, Jennifer R. Brown, Michael J. Franklin, and Sarah L. Codd were co-authors of the article, 'Microbial and algal alginate gelation characterized by magnetic resonance' in the journal 'Journal of biotechnology' which is contained within this thesis.The research presented uses nuclear magnetic resonance (NMR) experimental techniques to study systems of geochemical and biological processes. This thesis first presents an introduction to the NMR experimental concepts and data analysis. Several experimental systems are then described in detail: biological reduction of uranium; biofilm growth in porous media; and solutions and gels of alginate, a polymer molecule commonly found in the biofilm polymeric matrix. Bioremediation of heavy metal contaminants such as uranium around nuclear waste storage sites is an important environmental problem. Uranyl (UO 2 ²+) is soluble in water, while uraninite (UO 2) precipitates as nanoparticles. Certain types of bacteria are able to use uranium as the electron acceptor and reduce uranyl ions to uraninite. The experiments presented used a solution of uranyl ions that was reduced by a sulfur reducing bacteria and were studied using images and relaxation measurements. The growth of biofilms in the subsurface may also be used for bioremediation. Biofilms form when bacteria attach to surfaces and then produce and live within a polymeric matrix known as the extracellular polymeric substance (EPS). Experiments were done on a biofilm grown through the pore structure of a model bead pack. During the biofilm growth, displacement-relaxation correlation experiments were performed which were able to separate the biofilm phase from the bulk fluid phase using relaxation information. The results presented show that during biofilm growth very little convective flow occurs through the biofilm phase, while pore clogging causes channeling that increases the flow through non-biofilm filled pores and increases hydrodynamic dispersion. The EPS matrix of a biofilm contains DNA, proteins, and biologically produced polymers. Some biofilms such as those produced by the bacteria Pseudomonas aeruginosa contain the polymer alginate. Three biologically produced alginates were compared: alginate produced by algae, alginate produced by P. aeruginosa FRD1153, and alginate produced by P. aeruginosa FRD1. A diffusive reaction gelation process was used to produce heterogeneous gels which were analyzed both during and after gelation. Homogeneous gels and solutions were studied using relaxation dispersion techniques. Differences in hydrogen exchange processes, polymer conformation, and gel structure were analyzed.