Scholarly Work - Mechanical & Industrial Engineering
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/8878
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Item Evaluation of the bonding properties between low-value plastic fibers treated with microbially-induced calcium carbonate precipitation and cement mortar(Elsevier BV, 2022-11) Espinal, Michael; Kane, Seth; Ryan, Cecily; Phillips, Adrienne J.; Heveran, ChelseaPlastic fiber reinforced cementitious materials offer the potential to increase the reusability of plastic waste and create lower-CO2 cementitious composites. However, the bonding properties of many plastic types with ordinary Portland cement (OPC) are largely unknown. This work employs single fiber pullout (SFPO) tests to quantify the interfacial bonding properties of polyvinyl chloride, low-density polyethylene, polypropylene, polystyrene, and acrylonitrile butadiene styrene embedded in OPC mortar. The interfacial bonding properties were compared for fibers either treated with microbially-induced calcium carbonate precipitation (MICP) or left untreated. SFPO tests revealed that plastic type had a large influence over bonding properties. Specifically, the fiber surface energy, as estimated from water contact angle measurements, was found to be the driving factor of bond strength. ABS had the highest surface energy and demonstrated the strongest bonding out of all plastic types studied. However, MICP treatment of fibers did not increase the interfacial bond strength for any of the plastics studied. The thick and inconsistent coverage of biomineral over the fiber surface from MICP is likely attributed to preventing an increase in bond strength. These results contribute to the design and application of plastic-reinforced mortars by comparing bonding properties for a range of typically low-value, unrecycled plastic types.Item Hydraulic bulge testing to compare formability of continuous and stretch broken carbon fiber reinforced polymer composites(Springer Science and Business Media LLC, 2023-02) Shchemelinin, Yoni; Nelson, Jared W.; Ryan, Cecily; Bajwa, Dilpreet S.; Cairns, Doug; Amendola, RobertaThe use of carbon fiber reinforced polymer composites has increased with the increased need for high-strength, low-density materials, particularly in the aerospace industry. Stretch broken carbon fiber (SBCF) is a form of carbon fiber created by statistically distributed breakage of aligned fibers in a tow at inherent flaw points, resulting in a material constituted of collimated short fibers with an average length larger than chopped fibers. While continuous carbon fiber composites have desirable material properties, the limited ability to form in complex geometries prevents their wide adoption. SBCF composites exhibit pseudo-plastic deformation that can potentially enable the use of traditional metal forming techniques like stamping and press forming, widely used for mass production applications. To investigate the formability of carbon fiber reinforced polymer composites prepared with either continuous or stretch broken Hexcel IM-7 12 K fibers and impregnated with Huntsman RDM 2019–053 resin, hydraulic bulge testing was performed at atmospheric pressure and elevated temperature to explore the strain behavior under biaxial stress conditions for the material system. Results based on deformation of surface patterning, bulge apex displacement and measurement of the bulge internal surface and volume, support the enhanced formability of the SBCF material when compared to its continuous counterpart. The SBCF enhanced formability is characterized by an axisymmetric stress response and a failure mechanism similar to the one observed for sheet metalItem Biochar as a Renewable Substitute for Carbon Black in Lithium-Ion Battery Electrodes(American Chemical Society, 2022-09) Kane, Seth; Storer, Aksiin; Xu, Wei; Ryan, Cecily; Stadie, Nicholas P.Lignin-derived biochar was prepared and characterized toward potential applications as a conductive electrode additive and active lithium host material within lithium-ion batteries (LIBs). This biochar was specifically selected for its high electrical conductivity, which is comparable to that of common conductive carbon black standards (e.g., Super P). Owing to its high electrical conductivity, this biochar serves as an effective conductive additive within electrodes comprising graphite as the active material, demonstrating slightly improved cell efficiency and rate capability over those of electrodes using carbon black as the additive. Despite its effectiveness as a conductive additive in LIB anodes, preliminary results show that the biochar developed in this work is not suitable as a direct replacement for carbon black as a conductive additive in LiFePO4 cathodes. This latter insufficiency may be due to differences in particle geometry between biochar and carbon black; further optimization is necessary to permit the application of biochar as a general-purpose conductive additive in LIBs. Nevertheless, these investigations combined with an assessment of greenhouse gas emissions from biochar production show that replacing carbon black with biochar can be an effective method to improve the sustainability of LIBs.Item Biochar as a Renewable Substitute for Carbon Black in Lithium-Ion Battery Electrodes(American Chemical Society, 2022-09) Kane, Seth; Storer, Aksiin; Xu, Wei; Ryan, Cecily; Stadie, Nicholas P.Lignin-derived biochar was prepared and characterized towards potential applications as a conductive electrode additive and active lithium host material within lithium-ion batteries (LIBs). This biochar was specifically selected for its high electrical conductivity, which is comparable to that of common conductive carbon black standards (e.g., Super P). Owing to its high electrical conductivity, this biochar serves as an effective conductive additive within electrodes comprised of graphite as the active material, demonstrating slightly improved cell efficiency and rate capability over electrodes using carbon black as the additive. Despite its effectiveness as a conductive additive in LIB anodes, preliminary results show that the biochar developed in this work is not suitable as a direct replacement for carbon black as a conductive additive in LiFePO4 (LFP) cathodes. This latter insufficiency may be due to differences in particle 2 geometry between biochar and carbon black; further optimization is necessary to permit the application of biochar as a general-purpose conductive additive in LIBs. Nevertheless, these investigations combined with an assessment of greenhouse gas emissions from biochar production show that replacing carbon black with biochar can be an effective method to improve the sustainability of LIBs.