Engineering Commons^™

Adaption Of Catechol And Reversible Addition-Fragmentation Chain-Transfer (Raft) Chemistries For Water-Based Applications, Olabode Oyeneye

Electronic Thesis and Dissertation Repository

Incorporating the binding chemistry of catechol functionality with RAFT chemistry offers a facile and simplified approach for developing a suite of new 2D and 3D hybrid materials with tailored morphologies. Leveraging both chemistries by synthesizing catechol-end functionalized RAFT agents and catechol-containing monomeric species for RAFT (co)polymerization, this dissertation examined a new series of advanced materials that were designed for water-based applications including model flocculants, thermoresponsive hydrogels, adsorbents and underwater adhesives.

To prepare the RAFT agents, novel trithiocarbonates with several catechol end R groups (as postpolymerization anchors) were synthesized that differ in their carbonyl α-substituents (Dopa-CTAs). These materials were evaluated for …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Study Of Motion Of Agglomerates Through A Fluidized Bed, Muhammad Owais Iqbal Bhatti

Electronic Thesis and Dissertation Repository

Formation of agglomerates in Fluid Cokers^TM can cause operating problems, such as excessive shed fouling, which can lead to premature unit shut down. Better understanding of how agglomerates move through a fluidized bed can help improve the design and operation of Fluid Cokers^TM and minimize the risk of agglomerates reaching regions where they cause problems.

To identify key factors in agglomerates motion in a fluidized bed, a new two-dimensional (2D) Radioactive Particle Tracking (RPT) method was developed which tracks model agglomerates motion. In conjunction, a tribo-electric method was used to determine bubble flow distribution in the fluidized bed. …

Synthesis Of Vo2 Nanomaterials Using Green Solvents For Thermochromic Window Coatings, Hanna Qin

Electronic Thesis and Dissertation Repository

Progress in the development of energy-efficient coatings has led to recent investigations of smart windows with the ability to control heat and light. Of particular interest for this dissertation is the fabrication of vanadium dioxide (VO₂) thermochromic nanomaterials using an environmentally friendly approach with good performance for optical switching. Tungsten (W) doped VO₂/GO (graphene oxide) hybrids were successfully prepared using a one-step hydrothermal method. At 2 at. % doping, VO₂ nanotubes were successfully synthesized with tunable phase transition temperatures (T_c) achieved as low as 42^oC. In addition, various experimental parameters including …

Crystal Engineering Of Active Pharmaceutical Ingredients With Low Aqueous Solubility And Bioavailability, Jenna M. Skieneh

Electronic Thesis and Dissertation Repository

Approximately 75% of new molecular entities approved by the Food and Drug Administration (FDA) for use in the pharmaceutical industry are found to have poor aqueous solubility. This undesirable attribute leads to consequences such as higher doses required to reach therapeutic levels, greater vulnerability to food effects, lesser fraction absorbed in the small intestine and damage to the environment due to increased quantity of excretion. The addition of an excipient (i.e. a FDA approved inactive ingredient) to the molecular structure of an active pharmaceutical ingredient (API) through intermolecular bonding is of growing interest because the properties of the API can …

Hydrodynamics In The Gas-Driven Inverse Liquid-Solid Fluidized Bed, Jiaqi Huang

Electronic Thesis and Dissertation Repository

A novel reactor named Gas-Driven Inverse Liquid-Solid Fluidized Bed (GDFB for short) was developed in this research. A vertical baffle divides the column into a riser and a downer. Inverse fluidization is driven by the gas and occurs in the downer, where hydrodynamics and their influencing factors were studied. In the solid-baffle system, four fluidization regimes were observed, including the packed bed, semi-fluidized bed, fully-fluidized bed, and circulating bed. Bed expansion ratio was higher for particles with a higher density and a smaller solids loading. Moreover, the average particle velocity was proportional to superficial gas velocity and higher for denser …

Performance Characterization Of Coagulation Pretreatment For Two Industrial Effluents, Jing Wan

Electronic Thesis and Dissertation Repository

In this work, performances of coagulation and flocculation were tested for two different industrial effluents. Coagulation-Flocculation and activated carbon adsorption were applied for the remediation of oil sands process-affected water (OSPW), generated from oil sands operations in Alberta, Canada. OSPW is a complex mixture of suspended solids, various suspended and dissolved organic compounds. Alum and natural coagulant Opuntia ficus-indica (OFI) were used as the coagulants, and the process was optimized to improve the removal of turbidity and dissolved organic carbon (DOC). The maximum removal of 98% and 63% in turbidity and DOC from OSPW, respectively occurred at pH=6.32, with an …

Regeneration Potential Of Activated Petroleum Coke For Application In Oil Sands Process-Affected Water, Sreejon Das

Electronic Thesis and Dissertation Repository

Cost effective regeneration of spent adsorbent is crucial for large scale application of adsorption as a viable separation process. While adsorption studies are abundant in literature, systematic and comprehensive regeneration studies are seldom reported in open literature. A proprietary activated carbon from petroleum coke was used for the removal of model naphthenic acids (NAs) and organic compounds from oil sands process-affected water (OSPW). A systematic and comprehensive study was conducted to regenerate the adsorbents. Methanol with aqueous NaOH (pH adjusted to around 12) was applied to regenerate the spent commercially available granular activated carbon (GAC) and activated petroleum-coke (APC). Optimization …

Preparation And Coating Of 5-Asa Pellets With A Novel Rotating Fluidized Bed, Shijia Guan

Electronic Thesis and Dissertation Repository

Although Mesalazine (5-ASA) demonstrates huge popularity in treating inflammatory bowel disease (IBD) due to its local effect on intestinal and colonic mucosa, it still demands more accurate and effective delivery of 5-ASA. As pellets embrace various technological and therapeutic advantages over the single-unit dosage form, this study aims at developing and optimizing the drug-loading and coating processes of 5-ASA pellets with a novel rotating fluidized bed. Powder layering and powder coating techniques, which are the same in essence, were applied in the drug-loading and coating processes, respectively. Three different coatings of 5-ASA pellets were achieved, resulting in extended, delayed and …