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This dissertation investigates the potential for enzyme induced carbonate cementation as an alternative to Portland cement for creating building material from sand aggregate. We create a solution of urease enzyme, calcium chloride (CaCl2), and urea in water and added sand. The urease catalyzes the synthesis of carbonate from urea, and

This dissertation investigates the potential for enzyme induced carbonate cementation as an alternative to Portland cement for creating building material from sand aggregate. We create a solution of urease enzyme, calcium chloride (CaCl2), and urea in water and added sand. The urease catalyzes the synthesis of carbonate from urea, and the carbonate then bonds with a dissociated calcium ion and precipitates from the solution as calcium carbonate (CaCO3). This precipitate can form small crystal bridges at contacts between sand grains that lock the sand grains in place. Using enzyme induced carbonate precipitation we created a cemented sand sample with a maximum compressive strength of 319 kPa and an elastic modulus of approximately 10 MPa. Images from the SEM showed that a major failure mechanism in the cemented samples was the delamination of the CaCO3 from the sand grains. We observed that CaCO3 cementation did not when solutions with high concentrations of CaCl2 and urea were used.
ContributorsBull, Michael Ryan (Author) / Kavazanjian, Edward (Thesis director) / Chawla, Nikhilesh (Committee member) / Barrett, The Honors College (Contributor) / Materials Science and Engineering Program (Contributor)
Created2014-05
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Nature is a master at organizing biomolecules in all intracellular processes, and researchers have conducted extensive research to understand the way enzymes interact with each other through spatial and orientation positioning, substrate channeling, compartmentalization, and more.

DNA nanostructures of high programmability and complexity provide excellent scaffolds to arrange multiple molecular/macromolecular

Nature is a master at organizing biomolecules in all intracellular processes, and researchers have conducted extensive research to understand the way enzymes interact with each other through spatial and orientation positioning, substrate channeling, compartmentalization, and more.

DNA nanostructures of high programmability and complexity provide excellent scaffolds to arrange multiple molecular/macromolecular components at nanometer scale to construct interactive biomolecular complexes and networks. Due to the sequence specificity at different positions of the DNA origami nanostructures, spatially addressable molecular pegboard with a resolution of several nm (less than 10 nm) can be achieved. So far, DNA nanostructures can be used to build nanodevices ranging from in vitro small molecule biosensing to sophisticated in vivo therapeutic drug delivery systems and multi-enzyme networks.

This thesis focuses on how to use DNA nanostructures as programmable biomolecular scaffolds to arranges enzymatic systems. Presented here are a series of studies toward this goal. First, we survey approaches used to generate protein-DNA conjugates and the use of structural DNA nanotechnology to engineer rationally designed nanostructures. Second, novel strategies for positioning enzymes on DNA nanoscaffolds has been developed and optimized, including site-specific/ non site-specific protein-DNA conjugation, purification and characterization. Third, an artificial swinging arm enzyme-DNA complex has been developed to mimic substrate channeling process. Finally, we extended to build a artificial 2D multi-enzyme network.
ContributorsYang, Yuhe Renee (Author) / Yan, Hao (Thesis advisor) / Liu, Yan (Thesis advisor) / Chen, Julian (Committee member) / Hayes, Mark (Committee member) / Arizona State University (Publisher)
Created2016