Chemical Engineering Commons^™

Theoretical Investigation Of Heterogeneous Catalysis At The Solid–Liquid Interface For The Conversion Of Lignocellulosic Biomass Model Molecules, Muhammad Faheem

Theses and Dissertations

Catalytic conversion of biomass-derived oxygenates to fuels and value-added chemicals is a promising strategy in the search for renewable and sustainable energy sources. Most relevant catalytic processes are carried out in an aqueous environment using supported transition metal catalysts. The reaction network consists of multiple series and parallel pathways leading to formation of hydrogen, alkanes, and lighter oxygenates. The final product distribution ultimately depends on the sequence and competition of C−C, C−O, C−H, and O−H bonds scissions. Ethylene glycol (EG) is the simplest model molecule of various biomass-derived polyols that has a C:O stoichiometry of 1:1 and contains all relevant …

A Non-Destructive Method For Measuring The Mechanical Properties Of Ultrathin Films Prepared By Atomic Layer Deposition, Qinglin Zhang, Xingcheng Xiao, Yang-Tse Cheng, Mark W. Verbrugge

Chemical and Materials Engineering Faculty Publications

The mechanical properties of ultrathin films synthesized by atomic layer deposition (ALD) are critical for the liability of their coated devices. However, it has been a challenge to reliably measure critical properties of ALD films due to the influence from the substrate. In this work, we use the laser acoustic wave (LAW) technique, a non-destructive method, to measure the elastic properties of ultrathin Al₂O₃ films by ALD. The measured properties are consistent with previous work using other approaches. The LAW method can be easily applied to measure the mechanical properties of various ALD thin films for multiple …

Gas-Phase, Catalytic Hydrodeoxygenation Of Propanoic Acid Over Supported Group Viii Noble Metals, Yuliana K. Lugo José

Theses and Dissertations

Recent advances for the deoxygenation of biomass, have demonstrated that hydrodeoxygenation (HDO) is one of the most promising route for the upgrading pyrolysis bio-oils. Catalytic hydrodeoxygenation of pyrolysis bio-oil have shown to be an efficient and economical process, since the raw materials consist mainly of waste. Propanoic Acid (PAc) is considered as one of the main constituents of pyrolysis bio-oils. However, these carboxylic acids are extremely corrosive and difficult to deoxygenate. Therefore, much effort have been given to the development of novel catalytic techniques, to improve the activity, stability and selectivity for the HDO of carboxylic acids.

This dissertation explores …

Synthesis, Characterization And Evaluation Of Ir-Based Bimetallic Catalysts, You Jung Song

Theses and Dissertations

This dissertation considers effective bimetallic preparation for supported Ir-based bimetallic catalysts and their catalytic activity. Since bimetallic catalysts exhibit significantly different catalytic and chemical properties than their corresponding monometallic components by providing enhanced selectivity, stability and /or activity, many monometallic catalysts in industrial processes have been replaced by bimetallic catalysts. However, conventional synthetic methods used to produce monometallic and bimetallic catalysts often result in wide particle size distributions and non-uniform materials which can be difficult to characterize on a fundamental level. Two alternate preparation methods, dendrimer templating and electroless deposition, are developed and compared with conventional incipient wetness method. In …

Ultrathin Graphene Oxide Membranes/Coatings For Separations, Hang Li

Theses and Dissertations

Graphene oxide (GO) was utilized as a novel material for making ultrathin membranes for gas separation and for making functional coatings for nano-/ultra-filtration in oil/water separation. Fundamental separation mechanisms by ultrathin GO membranes/coatings and potential applications were explored. This work can be divided into three parts. In the first part, ultrathin GO membranes supported on flat and smooth anodic aluminum oxide (AAO) substrates, with thickness down to 1.8 nm, were prepared by a facile vacuum filtration method. The as-prepared GO membranes were then studied for single-gas permeation and hydrogen mixture separation. It was revealed that the separation mechanism for the …

Synthesis Of Graphitic Carbon Nanostructures And Use As Electrocatalyst For Oxygen Reduction Reaction, Daniel A. Moniot

Theses and Dissertations

Graphitic carbon nanostructure (GCN) was synthesized by a simple procedure using cobalt(II) gluconate as a precursor and used as a catalyst support for polymer electrolyte membrane (PEM) fuel cell cathode. A novel stabilization procedure was developed to enhance the thermal stability of the GCN support. Support stabilization resulted in well-defined crystalline graphitic hollow structures as confirmed by highresolution transmission electron microscope (HRTEM). The prepared GCNs are used as support for depositing platinum nanoparticles (size) by modified polyol process. Rotating ring disk electrode (RRDE) and fuel cell studies were carried out to evaluate the catalyst performance. Cycling studies (0.6-1.0 V vs. …

Polymer Nano-Dielectrics For High Density Energy Storage, Sayful Islam Md

Theses and Dissertations

Military and commercial users require next-generation polymer dielectric materials for pulse power and power conditioning applications with rise times less than 1 ms and AC power at frequencies ranging from kHz to MHz. These power density and rate capability requirements necessitate the use of dielectric capacitors that store energy via polarization of electrons in molecular scale dipoles. Multiphase polymer composites and all-polymer dielectrics could be new kinds of materials to meet this acute need for capacitors with compact size and high rate capability.

The polymer nanocomposite (PNC) approach to achieve high energy density employed a “colossal” dielectric constant material, calcium …

Catalysis In Petroleum Coking, Robert Khakimov, Anya Heinimann, Enrico Martinez, Hyun-Tae Hwang

The Summer Undergraduate Research Fellowship (SURF) Symposium

The petroleum industry is challenged with the processing of present heavy crudes caused by high composition of sulfur and metals, which lead to a higher yield of unfavorable bottom product as vacuum residue. Vacuum residue is the least valuable fraction of four, such as saturates, aromatics, resins and asphaltenes. However, it can be upgraded to recover more valuable products such as light hydrocarbons. The Delayed Coking process is going to be used to transform the vacuum residue at different experimental conditions. First of all, the behavior of the vacuum residue needs to be analyzed with no additions in feedstock. Secondly, …

Flow Regime Transition In Trickle Bed Reactors, Eric P. Lehmann, Gregory Honda, Arvind Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

In industry, trickle bed reactors – fixed beds in which gas and liquid reactants flow concurrently downward through catalyst - are often operated at gas and liquid superficial velocities near the transition boundaries between flow regimes, especially the transition between trickle to pulse flow. Previous studies have characterized flow regime transitions as sharp transitions that occur at single superficial liquid velocities for a fixed superficial gas velocity. In reality, transitions evolve gradually over a range of superficial liquid velocities. Experiments were conducted in a fixed bed with air and water flowing concurrently downward using two different packing media. The transitions …

Polymer-Based Thermoelectric Devices, Stuart W. Hilsmier, Edward P. Tomlinson, Bryan Boudouris

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, over 50% of all energy generated in the US is lost as waste heat, and thermoelectric generators offer a promising means to recoup some of this energy, if their efficiency is improved. While organic thermoelectric materials lack the efficiency of their inorganic counterparts, they are composed of highly abundant resources and have low temperature processing conditions. Recently, a new class of redox-active polymers, radical polymers, has exhibited high electrical conductivity in an entirely amorphous medium. In addition, these radical polymers have a simple synthetic scheme and can be highly tunable to provide desired electrical properties. In this study, the …

The Kinetics Of A Palladium Precursor – Tobacco Mosaic Virus Reaction, Adi Banerjee, Mayo Adigun, Michael T. Harris

The Summer Undergraduate Research Fellowship (SURF) Symposium

There have been numerous developments in the field of production of metallic nanoparticles using biotemplates such as the Tobacco Mosaic Virus (TMV). Past research has looked at the conditions required to maximise nanoparticle formation. This study of the kinetics of a nanomaterial synthesis reaction using a biotemplate would elucidate the understanding of the controlled growth of nanoparticles, which can be applied in the fabrication of photocatalysts, electrical nanocircuits and solar cells. This study specifically focuses on the reaction between a palladium precursor and the TMV without an external reducing agent, where the palladium ion concentration is measured over time using …

Stability Of Aqueous Dispersions Of Titanium Dioxide Against Sedimentation And Aggregation, Guanrong Bai, Xilan Zhu, Elias I. Franses, David S. Corti, Yung-Jih Yang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Particles of titanium dioxide (TiO₂) are widely used as white pigments in paints and inks, due to their brightness and high refractive index. Yet, with TiO₂ having a high density (4.2 g/cm³), particles with typical sizes of 300 nm sediment rapidly even before significant agglomeration can occur. Thus, increasing the stability of TiO2 dispersions against sedimentation as well as aggregation is important. We studied the effect of sodium dodecyl sulfate (SDS), a commonly used dispersant, on the stability of aqueous dispersions of TiO₂ with weight fractions from 0.01 to 40. The sedimentation time of …

Formulation And Solution Of Contingency Constrained Acopf Problem With Pyomo, Stefanus D. Winarto, Jianfeng Liu, Carl D. Laird

The Summer Undergraduate Research Fellowship (SURF) Symposium

Power grids scattered around the world bring great importance to society as they are challenged to provide economically efficient and reliable power market. With consideration of possible system contingency, which refers to multi-scenario optimization where each scenario considers an individual transmission element failure, the determination of optimal generators’ set points in the transmission network is becoming even more essential and challenging. A problem formulation is developed to solve the optimal allocation and minimize the total operating cost for the nominal case while including a large number of contingency scenarios. To achieve that goal, traditional ACOPF (AC optimal power flow model) …

The Catalysis Of Delayed Petroleum Coking, Anya M. Heinimann, Robert Khakimov, Hyun-Tae Hwang, Enrico N. Martinez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Due to the decreasing crude oil quality (heavier crudes and increasing contaminant concentrations) methods for upgrading residues from the refining process, such as coking, are becoming increasingly important. Delayed coking, a method by which residues are thermally cracked (large heavy molecules broken into smaller lighter molecules), produces liquid products and solid coke which can both be sold for further profit. In order to increase the amount of liquid products produced since they are the most value added product of the coking process catalysts (platinum on 0.5% alumina and nickel (skeletal),molybdenum promoted (1 wt%)) were tested to see how they would …

Population Balance Modeling Of Conjugation In Enterococcus Faecalis, Jeremy Binagia, Vu Tran, Che-Chi Shu, Doraiswami Ramkrishna

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the bacteria species Enterococcus faecalis, transfer of plasmid pCF10 by conjugation between donor cells that possess sets of genes conferring drug resistance and recipient cells leads to the spread of this resistance in a population. A complex signaling molecule network is responsible for communication between recipient and donor cells. Up to this point, the nature of these signaling molecules has been modeled deterministically from the point of view of an “average” cell. While this view has been cured slightly by stochastic treatments, a model is needed that better accounts for the individual nature of each cell, each cell’s interactions …

Effect Of Twin Screw Granulator Process Parameters On Granule Attributes, Haosheng Xu, Ridade Sayin, James Litster

The Summer Undergraduate Research Fellowship (SURF) Symposium

Twin screw wet granulation has been considered as an efficient and effective technique of manufacturing granules (agglomerates made up of small particles) and has been widely applied in pharmaceutical industry. However, narrow granule size distributions are difficult to achieve. This study aims to elucidate the effect of process parameters such as liquid feed rate and screw configuration on the granule attributes through granule characterization. The methods used are sieve analysis (for size distribution), liquid distribution (determining the dye concentration in the granules) and density and porosity (percentage gas volume in the granule) analyses. A sieve shaker is used to divide …

Characterization Of Swelling Ratio And Water Content Of Hydrogels For Cartilage Engineering Applications, Emily E. Gill, Renay S.-C. Su, Julie C. Liu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Due to the high prevalence of arthritis and cartilage-related injuries, tissue engineers are studying ways to grow cartilage tissue replacements. Resilin, an elastomeric protein found in insect cuticles, is known for its extraordinary resilience and elasticity. In previous studies, recombinant resilin-based hydrogels, or cross-linked protein networks, exhibited potential for use in cartilage tissue scaffolds. Our lab successfully developed resilin-based proteins with a sequence based on the mosquito gene and showed that resilin-based hydrogels possess mechanical properties of the same order of magnitude as native articular cartilage. In addition, these mechanical properties can be controlled by changing the protein concentration. To …

Monitoring Hydroxyurea Treatment Of Sickle Cell Anemia, Adhit Ramamurthi, Jayachandran Devaraj, Doraiswami Ramkrishna

The Summer Undergraduate Research Fellowship (SURF) Symposium

Sickle cell is a hereditary disease affecting more than 100,000 people in the United States alone that causes hemoglobin in red blood cells to polymerize and turn the cell into a sickle shape, resulting in severe vaso-occlusive crises and ischemic attacks. Sickle cell patients often suffer from pain crises, with the number of pain crises linked to their prognosis, especially at a younger age. Currently, the drug hydroxyurea (HU) is used to treat the disease, with a measure of red blood cell volume (RBC MCV) as monitor for treatment progression. However, physicians have to wait atleast 120 days to identify …

Radical Polymers As Anodic Charge Extraction Layers In Small Molecule Organic Photovoltaic Devices, Krystopher S. Jochem, Aditya G. Baradwaj, Bryan W. Boudouris

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic photovoltaic (OPV) devices based on the copper (II) phthalocyanine(CuPc)/ fullerene(C₆₀) system are an innovative photovoltaic technology optimal for situations requiring low-cost, transparent, and flexible devices. Furthermore, the high degree of reproducibility of this system allows for the ready study of new OPV technologies. Here, we have used this system to elucidate systematic structure-property-performance relationships for a new OPV anode modifier. The addition of interfacial modifier materials between the organic CuPc/C₆₀ layers and the metallic anode drastically can improve efficiency. Radical polymers are a class of polymers with aliphatic backbones and pendent stabilized radical groups. Here, we …

Effect Of Sodium Dodecyl Sulfate And Sodium Chloride On The Stability Of Aqueous Dispersions Of Tio2 Particles Against Aggregation And Sedimentation, Xilan Zhu, Guanrong Bai, Elias I. Franses, David S. Corti, Yung-Jih Yang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Dispersions of TiO₂ particles are widely used as the main pigment in white inks for inkjet printers due to its brightness and high opacity. The TiO₂ particles, however, have a high density, and so the possible fast settling of these particles can cause maintenance problems for the printers and lower the printing quality. We studied the effect of sodium dodecyl sulfate (SDS), a commonly used dispersant, on the stability of 1 wt% TiO2 aqueous dispersions, both with and without NaCl, against aggregation and sedimentation. The sedimentation half time (t50), defined as the time need for the particles to …