Matching Items (56)

Comparative Life Cycle Assessment of Nano-Metal Embedded Water Treatment Resins

Description

In an effort to provide drinking water treatment options that are simple to operate, two hybrid resins have been developed that can treat multiple pollutants in a single step. A

In an effort to provide drinking water treatment options that are simple to operate, two hybrid resins have been developed that can treat multiple pollutants in a single step. A parent weak base anion exchange resin is embedded with nanoparticles made of either iron hydroxide or titanium dioxide (Fe-WBAX and Ti-WBAX, respectively). These provide targeted treatment for both arsenic and hexavalent chromium, common groundwater pollutants of recent regulatory significance. The project goal is to evaluate the environmentally preferable choice between Fe-WBAX and Ti-WBAX resin for simultaneous treatment of arsenic and hexavalent chromium in drinking water. The secondary goal is to identify where in the product life cycle is the most opportunity to reduce the environmental impact of the use of either product.

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Date Created
  • 2014-06-13

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Multi-Layer Optical Coatings Composed of Silicon Nanoparticles

Description

To compete with fossil fuel electricity generation, there is a need for higher efficiency solar cells to produce renewable energy. Currently, this is the best way to lower generation costs

To compete with fossil fuel electricity generation, there is a need for higher efficiency solar cells to produce renewable energy. Currently, this is the best way to lower generation costs and the price of energy [1]. The goal of this Barrett Honors Thesis is to design an optical coating model that has five or fewer layers (with varying thickness and refractive index, within the above range) and that has the maximum reflectance possible between 950 and 1200 nanometers for normally incident light. Manipulating silicon monolayers to become efficient inversion layers to use in solar cells aligns with the Ira. A Fulton Schools of Engineering research themes of energy and sustainability [2]. Silicon monolayers could be specifically designed for different doping substrates. These substrates could range from common-used materials such as boron and phosphorus, to rare-earth doped zinc oxides or even fullerene blends. Exploring how the doping material, and in what quantity, affects solar cell energy output could revolutionize the current production methods and commercial market. If solar cells can be manufactured more economically, yet still retain high efficiency rates, then more people will have access to alternate, "green" energy that does not deplete nonrenewable resources.

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Created

Date Created
  • 2016-12

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A Model of Nanoparticle Dispersion in Electrospun Nanofibers

Description

Polymer-nanoparticle composites (PNCs) show improved chemical and physical properties compared to pure polymers. However, nanoparticles dispersed in a polymer matrix tend to aggregate due to strong interparticle interactions. Electrospun nanofibers

Polymer-nanoparticle composites (PNCs) show improved chemical and physical properties compared to pure polymers. However, nanoparticles dispersed in a polymer matrix tend to aggregate due to strong interparticle interactions. Electrospun nanofibers impregnated with nanoparticles have shown improved dispersion of nanoparticles. Currently, there are few models for quantifying dispersion in a PNC, and none for electrospun PNC fibers. A simulation model was developed to quantify the effects of nanoparticle volume loading and fiber to particle diameter ratios on the dispersion in a nanofiber. The dispersion was characterized using the interparticle distance along the fiber. Distributions of the interparticle distance were fit to Weibull distributions and a two-parameter empirical equation for the mean and standard deviation was found. A dispersion factor was defined to quantify the dispersion along the polymer fiber. This model serves as a standard for comparison for future experimental studies through its comparability with microscopy techniques, and as way to quantify and predict dispersion in polymer-nanoparticle electrospinning systems with a single performance metric.

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Created

Date Created
  • 2016-12

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Development of ductile, amorphous metallic film at ambient conditions

Description

The overall goal of this project is to use metallic nanoparticles to develop a thin, ductile amorphous film at room temperature. Currently bulk metallic glasses are mainly formed via quenching,

The overall goal of this project is to use metallic nanoparticles to develop a thin, ductile amorphous film at room temperature. Currently bulk metallic glasses are mainly formed via quenching, which requires very high cooling rates to achieve an amorphous molecular structure. These formations often fail in a brittle manner. The advantages of using a bottom-up approach with amorphous nanoparticles at ambient conditions is that the ductility of the metal can be improved, and the process will be less energy intensive. The nanoparticles used are iron precursors with ATMP and DTPMP ligand stabilizers and dispersed in methanol. Three forms of experimentation were applied over the course of this project. The first was a simple, preliminary data collection approach where the particles were dispersed onto a glass slide and left to dry under various conditions. The second method was hypersonic particle deposition, which accelerated the particles to high speeds and bombarded onto a glass or silicon substrate. The third method used Langmuir-Blodgett concepts and equipment to make a film. Qualitative analyses were used to determine the efficacy of each approach, including SEM imaging. In the end, none of the approaches proved successful. The first approach showed inconsistencies in the film formation and aggregation of the particles. The results from the hypersonic particle deposition technique showed that not enough particles were deposited to make a consistent film, and many of the particles that were able to be deposited were aggregated. The Langmuir-Blodgett method showed potential, but aggregation of the particles and uneven film formation were challenges here as well. Although there are ways the three discussed experimental approaches could be optimized, the next best step is to try completely new approaches, such as convective assembly and 3D printing to form the ideal nanoparticle film.

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Date Created
  • 2016-12

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Protein-mediated Synthesis of Gold Nanoparticles

Description

Gold nanoparticles are valuable for their distinct properties and nanotechnology applications. Because their properties are controlled in part by nanoparticle size, manipulation of synthesis method is vital, since the chosen

Gold nanoparticles are valuable for their distinct properties and nanotechnology applications. Because their properties are controlled in part by nanoparticle size, manipulation of synthesis method is vital, since the chosen synthesis method has a significant effect on nanoparticle size. By aiding mediating synthesis with proteins, unique nanoparticle structures can form, which open new possibilities for potential applications. Furthermore, protein-mediated synthesis favors conditions that are more environmentally and biologically friendly than traditional synthesis methods. Thus far, gold particles have been synthesized through mediation with jack bean urease (JBU) and para mercaptobenzoic acid (p-MBA). Nanoparticles synthesized with JBU were 80-90nm diameter in size, while those mediated by p-MBA were revealed by TEM to have a size between 1-3 nm, which was consistent with the expectation based on the black-red color of solution. Future trials will feature replacement of p-MBA by amino acids of similar structure, followed by peptides containing similarly structured amino acids.

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Date Created
  • 2018-05

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Utilization of Nanoparticles for Identifying Fibrin Deposition in Neural Tissue

Description

The main objective of this research is to develop and characterize a targeted contrast agent that will recognize acute neural injury pathology (i.e. fibrin) after traumatic brain injury (TBI). Single

The main objective of this research is to develop and characterize a targeted contrast agent that will recognize acute neural injury pathology (i.e. fibrin) after traumatic brain injury (TBI). Single chain fragment variable antibodies (scFv) that bind specifically to fibrin have been produced and purified. DSPE-PEG micelles have been produced and the scFv has been conjugated to the surface of the micelles; this nanoparticle system will be used to overcome limitations in diagnosing TBI. The binding and imaging properties will be analyzed in the future to determine functionality of the nanoparticle system in vivo.

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Created

Date Created
  • 2014-05

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The Effect of Nanoparticle Diameter on TAT-mediated Delivery to the CNS In Vivo

Description

Neurological disorders are difficult to treat with current drug delivery methods due to their inefficiency and the lack of knowledge of the mechanisms behind drug delivery across the blood brain

Neurological disorders are difficult to treat with current drug delivery methods due to their inefficiency and the lack of knowledge of the mechanisms behind drug delivery across the blood brain barrier (BBB). Nanoparticles (NPs) are a promising drug delivery method due to their biocompatibility and ability to be modified by cell penetrating peptides, such as transactivating transciptor (TAT) peptide, which has been shown to increase efficiency of delivery. There are multiple proposed mechanisms of TAT-mediated delivery that also have size restrictions on the molecules that can undergo each BBB crossing mechanism. The effect of nanoparticle size on TAT-mediated delivery in vivo is an important aspect to research in order to better understand the delivery mechanisms and to create more efficient NPs. NPs called FluoSpheres are used because they come in defined diameters unlike polymeric NPs that have a broad distribution of diameters. Both modified and unmodified 100nm and 200nm NPs were able to bypass the BBB and were seen in the brain, spinal cord, liver, and spleen using confocal microscopy and a biodistribution study. Statistically significant differences in delivery rate of the different sized NPs or between TAT-modified and unmodified NPs were not found. Therefore in future work a larger range of diameter size will be evaluated. Also the unmodified NPs will be conjugated with scrambled peptide to ensure that both unmodified and TAT-modified NPs are prepared in identical fashion to better understand the role of size on TAT targeting. Although all the NPs were able to bypass the BBB, future work will hopefully provide a better representation of how NP size effects the rate of TAT-mediated delivery to the CNS.

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Date Created
  • 2016-05

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Effects of Aging and Crystallization Time and Temperature in the Synthesis of Ideal Zeolite Linde Type A

Description

One of the grand challenges of engineering is to provide access to clean water because it is predicted that by 2025 more than two thirds of the world’s population will

One of the grand challenges of engineering is to provide access to clean water because it is predicted that by 2025 more than two thirds of the world’s population will face severe water shortages. To combat this global issue, our lab focuses on creating a novel composite membrane to recover potable water from waste. For use as the water-selective component in this membrane design Linde Type A zeolites were synthesized for optimal size without the use of a template. Current template-free synthesis of zeolite LTA produces particles that are too large for our application therefore the particle size was reduced in this study to reduce fouling of the membrane while also investigating the nanoparticle synthesis mechanisms. The time and temperature of the reaction and the aging of the precursor gel were systematically modified and observed to determine the optimal conditions for producing the particles. Scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray analysis were used for characterization. Sub-micron sized particles were synthesized at 2 weeks aging time at -8°C with an average size of 0.6 micrometers, a size suitable for our membrane. There is a limit to the posterity and uniformity of particles produced from modifying the reaction time and temperature. All results follow general crystallization theory. Longer aging produced smaller particles, consistent with nucleation theory. Spinodal decomposition is predicted to affect nucleation clustering during aging due to the temperature scheme. Efforts will be made to shorten the effective aging time and these particles will eventually be incorporated into our mixed matrix osmosis membrane.

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Date Created
  • 2016-05

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Direct nose-to-brain delivery of targeted polymeric nanoparticles

Description

There is growing interest in intranasal delivery of therapeutics because of direct nose-to-brain pathways which are able to bypass biological barriers, such as the blood-brain barrier (BBB), that have historically

There is growing interest in intranasal delivery of therapeutics because of direct nose-to-brain pathways which are able to bypass biological barriers, such as the blood-brain barrier (BBB), that have historically limited our ability to effectively deliver drugs to the central nervous system (CNS). Since these pathways were first discovered, there has been significant preclinical success in delivering a wide range of therapeutics to the CNS with additional growing efforts to further improve delivery through nanoparticle drug delivery systems. Here we sought to improve intranasal delivery of DiR, a lipophilic small molecule cyanine dye, to the CNS by surface modifying a poly (lactic-co-glycolic acid) (PLGA) nanoparticle with a short peptide derived from the rabies virus glycoprotein (RVG). The specific aims of this thesis were to evaluate administration route-dependent delivery of RVG nanoparticles to the CNS, and to identify anatomical transport pathways by which nanoparticles facilitate transport of small lipophilic molecules. Route-dependent delivery kinetics and distribution were studied by administering DiR loaded nanoparticles to healthy Balb/C mice. Specific tissues were homogenized and the fluorescent intensity of DiR was measured and compared to control tissue spiked with known amounts of dye. While bioavailability of DiR after intranasal administration was near 0% with minimal exposure to peripheral organs, quick and efficient delivery to the CNS was still observed. CNS delivery after intranasal administration was rapid with peak concentrations at 30 minutes post-administration followed by broad clearance by 2 hours. Regional differences of delivery of DiR to the CNS demonstrated engagement of direct nose-to-brain transport pathways with high delivery being observed to the olfactory bulb, brain stem, and trigeminal nerve. RVG modification however presented only modest targeting benefits. In conclusion, the biodistribution of DiR after intranasal administration of DiR loaded nanoparticles showed high potential for the direct nose-to-brain delivery while limiting peripheral exposure of lipophilic small molecule drugs.

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Date Created
  • 2016-05

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Development of a Novel Smart Contrast Agent for Magnetic Resonance Imaging

Description

Smart contrast agents allow for noninvasive study of specific events or tissue conditions inside of a patient's body using Magnetic Resonance Imaging (MRI). This research aims to develop and characterize

Smart contrast agents allow for noninvasive study of specific events or tissue conditions inside of a patient's body using Magnetic Resonance Imaging (MRI). This research aims to develop and characterize novel smart contrast agents for MRI that respond to temperature changes in tissue microenvironments. Transmission Electron Microscopy, Nuclear Magnetic Resonance, and cell culture growth assays were used to characterize the physical, magnetic, and cytotoxic properties of candidate nanoprobes. The nanoprobes displayed thermosensitve MR properties with decreasing relaxivity with temperature. Future work will be focused on generating and characterizing photo-active analogues of the nanoprobes that could be used for both treatment of tissues and assessment of therapy.

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Date Created
  • 2014-05