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Chemical Engineering

LSU Doctoral Dissertations

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Nanoparticles

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Full-Text Articles in Engineering

Non-Equilibrium Colloidal Phenomena In Magnetic Fields And Photoillumination: From Controlling Living Microbots To Understanding Microplastics, Ahmed Al Harraq Jan 2023

Non-Equilibrium Colloidal Phenomena In Magnetic Fields And Photoillumination: From Controlling Living Microbots To Understanding Microplastics, Ahmed Al Harraq

LSU Doctoral Dissertations

Colloids are a ubiquitous class of materials composed of microscopic particles suspended in a continuous phase which are found in everyday products and in nature. Colloids are also useful models for studying the spontaneous arrangement of matter from individual building blocks to mesophases. Standard treatment of colloid science is based on the assumption of equilibrium conditions, as defined in traditional thermodynamics. However, novel assembly mechanisms and motility are unlocked by pushing colloids away from equilibrium using external energy. In addition, many colloids in nature and in industrial applications exchange energy and mass with the surrounding environment thus behaving in a …


Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete Jul 2022

Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete

LSU Doctoral Dissertations

The world’s dependence on petroleum hydrocarbons has led to significant environmental implications. For example, oil spills cause lasting environmental damage, and the increase of plastics in the marine environment has been growing, specifically, microplastics that can be difficult to detect due to their small size. Petroleum hydrocarbons occur naturally in nearly all marine environments, which has allowed hundreds of microorganisms to evolve to utilize these hydrocarbons as their primary energy source. These microbes are classified as hydrocarbonoclastic and are utilized to remove spilled oil biodegradation. Over the last ten years, progress has been made in the biodegradation of oil spills …


Tunable Luminescence Of Rare Earth Doped Nanophosphors Via Adaptive Optical Properties Of Transition Metals, Pragathi Darapaneni Mar 2020

Tunable Luminescence Of Rare Earth Doped Nanophosphors Via Adaptive Optical Properties Of Transition Metals, Pragathi Darapaneni

LSU Doctoral Dissertations

Over the past decades, the development of light-emitting diodes (LEDs) to produce a wide range of wavelengths has revolutionized the solid-state lighting industry due to their higher energy efficiency and operational lifetimes. These LEDs employ rare earth (RE) doped phosphors due to their stable emission wavelengths which can be amplified when sensitized by other RE dopants (Yb, Ce) or shell layer passivation. However, there has been a push to replace the RE elements in LEDs due to increased socioeconomic issues. One proposed alternative, transition metal (TM) dopants, is typically avoided due to their susceptibility to the local crystal environment resulting …


Catalytic Hydrogenation Of Co To Higher Alcohols, Nachal Devi Subramanian Jan 2011

Catalytic Hydrogenation Of Co To Higher Alcohols, Nachal Devi Subramanian

LSU Doctoral Dissertations

The interest in converting synthesis gas to alcohols and oxygenated fuel additives via CO hydrogenation is growing rapidly due to the increasing rise in oil prices. Among the potential end products, ethanol is desirable since it serves as a clean alternative fuel, a gasoline blend, and a hydrogen carrier to supply fuel cells. The high cost and limited availability of the most active/selective Rh-based catalysts has led to the development of base metal catalysts such as modified Cu-based catalysts. Literature suggests that a combination of Co (or Mn) with Cu can facilitate higher alcohol formation by a non-dissociative adsorption of …


Particle-Chemical Interactions And Environmental Chemodynamics Of Fine And Ultrafine Particles In A Natural Disaster Scenario, Nicholas A. Ashley Jan 2009

Particle-Chemical Interactions And Environmental Chemodynamics Of Fine And Ultrafine Particles In A Natural Disaster Scenario, Nicholas A. Ashley

LSU Doctoral Dissertations

The interactions of fine and ultrafine particles with chemicals play a dominant role in determining the mobility and availability of pollutants in the environment. Fine particles in sediments can sequester chemicals from the water column, and release volatile and semi-volatile organic compounds to the gas phase upon exposure to air. Ultrafine particles which are photoreactive can degrade these vapor-phase contaminants, and may transform the molecules into species which are more toxic or hazardous than the parent. As the widespread, commercial use of ultrafine particles becomes more common, understanding the chemodynamics of these particles and their interactions with chemicals in the …


Fabrication Of Core-Shell Nanoparticles, Zhanhu Guo Jan 2005

Fabrication Of Core-Shell Nanoparticles, Zhanhu Guo

LSU Doctoral Dissertations

Metallic Cu and Au shells were fabricated around cobalt nanoparticles. A new technique to coat nanoparticles with carbon coatings and poly(methyl methacrylate) (PMMA) was developed. The copper shell formation is a self-limiting process. A thin copper shell (0.82 nm) around the cobalt nanoparticle (1.56 nm) enhanced the magnetic property by increasing the blocking temperature from 124 K to 235 K for nanoparticles with a copper shell. The formed gold shell (0.67 nm) enhanced the cobalt nanoparticle magnetic property by increasing the blocking temperature above room temperature. The magnetic moment in the Co-Cu and Co-Au core-shell nanoparticle is much higher than …