Materials Science and Engineering Commons^™

Investigating The Thixotropy Of Fresh Struvite Cement-Based Composite: Insights On Mechanisms Of The Pastes’ Thixotropic Behavior, Ugochukwu Ewuzie, Abdulkareem O. Yusuf, Damilola Daramola, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Struvite (ST) recovered during wastewater treatment has been sparsely applied in cement-based composites. This study systematically evaluated the thixotropic behavior of cement-struvite (CST) pastes, a mix of 5–20 % ST by mass of cement, and proposed the interaction mechanisms leading to the pastes' thixotropy. The hysteresis loop area was used to establish the pastes' thixotropy and investigate its relationship with increased ST content, temperature, and yield stress. In the thixotropic behavior model used, the equilibrium shear stress was employed to examine the CST pastes' irreversible change; the characteristic time of deflocculation was used to study the flocs destruction process; and …

Vacuum Consistent Electrochemistry In Ionic Liquid Combined With Oxide Epitaxy, Yuji Matsumoto

Journal of Electrochemistry

We introduce our state-of-the art of “vacuum consistent electrochemistry” to an investigation of the interfaces between oxides and ionic liquid (IL). Pulsed laser deposition (PLD) has been one of the powerful and sophisticated techniques to realize nanoscale preparation of high-quality epitaxial oxide thin films. On the other hand, electrochemistry is a simple, very sensitive, and non-destructive analysis technique for solid-liquid interfaces. To ensure the reproducibility in experiment of the interfaces of such epitaxial oxide films, as well as bulk oxide single-crystals, with IL, we employ a home-built PLD-electrochemical (EC) system with IL as an electrolyte. The system allows one to …

Pm Irras Studies Of Organized Molecular Films At A Gold Electrode Surface, Zhang-Fei Su, Ai-Cheng Chen, Jacek Lipkowski

Journal of Electrochemistry

This feature article illustrates the potential of polarization modulation infrared reflection absorption spectroscopy (PM IRRAS) to provide molecular-level information about the structure, orientation and conformation of constituents of thin films at electrode surfaces. PM IRRAS relies on the surface selection rules stating that the p-polarized IR beam is enhanced, while the s-polarized beam is attenuated at the metal surface. The difference between p- and s-polarized beams eliminates the background of the solvent and provides IR spectra at a single electrode potential. In contrast, two other popular in situ IR spectroscopic techniques, namely, subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS) …

Redox-Active Monolayers On Ito Prepared By Post-Amidation And Direct Esterification And Their Spectroelectrochemical Characterization, Takamasa Sagara, Sae Nakai, Ryusuke Yofu, Shota Kojin

Journal of Electrochemistry

A redox-active monolayer on an optically transparent electrode constitutes a typical platform for spectroelectrochemical sensing. The necessity for its sophistication arises from the availability of multi-dimensional sensing signals. Simultaneous monitoring of the redox current and color change synchronized with the oxidation state change significantly enhances sensitivity and selectivity. This study aimed to elucidate the modification of an indium tin oxide (ITO) electrode with a viologen monolayer with an ordered orientation. Novel methods were developed to immobilize a viologen molecule bearing a carboxyl group to form assembled monolayers through a condensation reaction using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide with N-hydroxy-succinimide (EDC/NHS). In the two methods …

Ambient Co2 Capture And Valorization Enabled By Tandem Electrolysis Using Solid-State Electrolyte Reactor, Yan-Bo Hua, Bao-Xin Ni, Kun Jiang

Journal of Electrochemistry

Electrocatalytic carbon dioxide reduction is a promising technology for addressing global energy and environmental crises. However, its practical application faces two critical challenges: the complex and energy-intensive process of separating mixed reduction products and the economic viability of the carbon sources (reactants) used. To tackle these challenges simultaneously, solid-state electrolyte (SSE) reactors are emerging as a promising solution. In this review, we focus on the feasibility of applying SSE for tandem electrochemical CO₂ capture and conversion. The configurations and fundamental principles of SSE reactors are first discussed, followed by an introduction to its applications in these two specific areas, …

Poly(Pyridinium Salt)S Containing 9,9-Bis(4- Aminophenyl)Fluorene Moieties With Various Organic Counterions Exhibiting Both Lyotropic Liquid-Crystalline And Light-Emitting Properties, Pradip K. Bhowmik, David King, Haesook Han, Andras F. Wacha, Matti Knaapila

Chemistry and Biochemistry Faculty Research

Main-chain conjugated and non-conjugated polyelectrolytes are an important class of materials that have many technological applications ranging from fire-retardant materials to carbon-nanotube composites, nonlinear optical materials, electrochromic materials for smart windows, and optical sensors for biomolecules. Here, we describe a series of poly(pyridinium salt)s-fluorene containing 9,9-bis(4-aminophenyl)fluorene moieties with various organic counterions that were synthesized using ring-transmutation polymerization and metathesis reactions, which are non-conjugated polyelectrolytes. Their chemical structures were characterized by Fourier transform infrared (FTIR), proton (1H) and fluorine 19 (19F) nuclear magnetic resonance (NMR) spectrometers, and elemental analysis. They exhibited polyelectrolytic behavior in dimethyl sulfoxide. Their lyotropic liquid-crystalline phases were …

Shrinkage Study In Photopolymerisable Hybrid Sol-Gel Through Holographic Patterning, Jamshed Aftab, Izabela Naydenova, Tatsiana Mikulchyk

Articles

Photopolymerisation induced shrinkage of holographic materials is one of the main factors which needs to be considered for designing holographic optical elements (HOEs) with high accuracy in light redirection with maximum efficiency. This work studies the shrinkage in photopolymerisable hybrid sol-gel (PHSG) by examining the properties of volume transmission gratings recorded in PHSG layers. It explores both the dependence of shrinkage on the holographic grating parameters (thickness, spatial frequency, slant angle) and the effect of material aging. By using the fringe-plane rotation model, shrinkage is found to have the maximum value of 1.37 % at 765 lines/mm (19.36° slant angle) …

Performance Evaluation Of Aminated Multi-Walled Carbon Nanotubes Incorporated With Green Synthesized Iron Nanoparticles For Toxic Dyes Sequestration From Textile Wastewater, Titus Chinedu Egbosiuba, Cynthia Chukwuemeka, Jonah Chukwudi Umeuzuegbu, Nwanneka Chibuzo Mmonwuba, Ugochukwu Ewuzie, Monday Uchenna Okoronkwo, Valentine Chikaodili Anadebe, Saheed Mustapha, Ambali Saka Abdulkareem, Jimoh Oladejo Tijani, Ashish Patel, Virendra Kumar Yadav

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study evaluates the performance of aminated multi-walled carbon nanotubes (AM-MWCNTs) integrated with zerovalent iron nanoparticles (ZVI) synthesized using cashew leaf (Anacardium occidentale) extract (AM-MWCNTs@ZVI) for the removal of Congo Red (CR) and Methylene Blue (MB) dyes from textile industrial wastewater. The nanocomposite was characterized using FTIR, XRD, BET, HRSEM, and HRTEM analyses, confirming its functional groups, crystalline structure, and enhanced surface area of 1050.4 m²/g. The ecological risk degree of the textile pollutants was assessed to determine the percentage concentrations of crystal violet, Congo red, methyl orange, methylene blue and rhodamine B. Batch adsorption experiments identified optimal …

Myceli-Yum: Elucidating Structure-Property Relationships For Polymer Degradation By Mycelial Digestion, Jordan Scott Ford

Master's Theses

Since the industrial entrance of polymer plastic materials, plastic has become ubiquitous in both everyday use and waste. Due to inefficiencies and knowledge gaps, current recycling methods are not able to account for the high scale of plastic waste, resulting in the bulk of this waste being landfilled, mishandled, and deposited in the environment. Mycelium, the microorganism responsible for fruiting mushroom bodies and mold growth, holds potential to reduce plastic waste and can potentially be utilized as a method of industrial recycling. Following a drug-design approach, the active site of mycelial enzymes responsible for natural biopolymer degradation have been assessed …

Strongly Confined Bi2se3 Quantum Dots Via Pulsed Laser Ablation In Liquids, Gregory Guisbiers, Rajendra Subedi, Burningham Burningham, Francisco Francisco Ruiz-Zepeda, Qiaohui Zhou, Xin Lu

Faculty Scholarship

Bismuth selenide (Bi2Se3) is a binary compound displaying a strong spin−orbit coupling, resulting in a narrow bulk bandgap material with a gapless metallic surface. By shrinking the size of Bi2Se3 within the strong confinement regime, its optoelectronic properties changed drastically. To achieve this goal, strongly confined Bi2Se3 quantum dots (QDs) were produced by pulsed laser ablation in liquids (PLAL). The laser used for the synthesis was a nanosecond Nd/YAG laser emitting at 1064 nm and pulsing at ∼13 mJ/pulse. The irradiation of the bulk target was performed at 1 kHz in acetone and lasted 5 min. Finally, the Bi2Se3 QDs …

Preparation And Modification Of Mxene Composites For Application In Electrochemical Energy Storage, Zhang-Hai You, Ding-Ze Lu, Kiran Kumar Kondamareddy, Wen-Ju Gu, Peng-Fei Cheng, Jing-Xuan Yang, Rui Zheng, Hong-Mei Wang

Journal of Electrochemistry

With the acceleration of advanced industrialization and urbanization, the environment is deteriorating rapidly, and non-renewable energy resources are depleted. The gradual advent of potential clean energy storage technologies is particularly urgent. Electrochemical energy storage technologies have been widely used in multiple fields, especially supercapacitors and rechargeable batteries, as vital elements of storing renewable energy. In recent years, two-dimensional material MXene has shown great potential in energy and multiple application fields thanks to its excellent electrical properties, large specific surface area, and tunability. Based on the layered materials of MXene, researchers have successfully achieved the dual functions of energy storage and …

Three-Dimensional Melamine Carbon Sponge/Nai As Cathode Materials For Sodium-Ion Batteries, Qian-Ying Huang, Yue Liu, Zi-Xin Lin, Shu-Yi Zheng, Ting-Ting Mei, Yu-Ting Tang, Ying-He Zhang, Jun Liu

Journal of Electrochemistry

The sodium-iodine (Na-I) battery exhibits significant potential as an alternative energy storage device to the lithium-ion battery. However, its development is hindered by inadequate electrical and thermal stability, as well as the dissolution and shuttling of polyiodide. In this study, we report a preparation method for melamine carbon sponge (MC) via carbonizing a commercially available kitchen sponge. It was revealed that the as-prepared MC, composed of unique self-growing carbon nanotubes, could provide both physical and chemical adsorption capabilities for intermediate polyiodides to improve the electrochemical performance of NaI. Consequently, the NaI/MC electrode effectively minimized polyiodide dissolution and reduced the electrochemical …

Understanding The Morphology And Mass Transport Resistance Of Mesoporous Carbon-Supported Pemfc Based On Modeling Analysis, Hao Deng, Jia Liu, Zhong-Jun Hou

Journal of Electrochemistry

Mesoporous carbon supports mitigate Pt sulfonic poisoning through nanopore-confined Pt deposition, yet their morphological impacts on oxygen transport remain unclear. This study integrates carbon support morphology simulation with an enhanced agglomerate model to establish a mathematical framework elucidating pore evolution, Pt utilization, and oxygen transport in catalyst layers. Results demonstrate dominant local mass transport resistance governed by three factors: (1) active site density dictating oxygen flux; (2) ionomer film thickness defining shortest transport path; (3) ionomer-to-Pt surface area ratio modulating practical pathway length. At low ionomer-to-carbon (I/C) ratios, limited active sites elevate resistance (Factor 1 dominant). Higher I/C ratios improve …

Optimization Of Renewable Energy Systems: Comparative Analysis Of Advanced Algorithms And Photovoltaic-Electrolyzer Performance For Cost Reduction And Efficiency Enhancement, Mohamed-Amine Babay, Mustapha Adar, Ahmed Chebak, Mustapha Mabroukia

Journal of Electrochemistry

The increasing demand for cost-effective and efficient renewable energy solutions presents significant optimization challenges in hybrid energy systems. This paper addresses these challenges by conducting a comparative analysis of three advanced optimization algorithms—Lévy Flight Optimization (LFO), Archimedean Optimization (AO), and Quantum Gorilla Optimization (QGO)—to minimize the Total Net Present Cost (TNPC) and Levelized Cost of Energy (LCOE) in hybrid renewable energy systems. The study integrates critical cost parameters such as Capital Expenditure (CAPEX), Operational Expenditure (OPEX), replacement costs, and salvage values into an advanced optimization framework. Three system configurations are evaluated: Wind Turbines and Fuel Cells (WT/FC), Photovoltaic Systems and …

Theoretical Insights Into The Atomic And Electronic Structures Of Polyperyleneimide: On The Origin Of Photocatalytic Oxygen Evolution Activity, Yi-Qing Wang, Zhi Lin, Ming-Tao Li, Shao-Hua Shen

Journal of Electrochemistry

Polymeric perylene diimide (PDI) has been evidenced as a good candidate for photocatalytic water oxidation, yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration. Herein, with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern, the electronic structure is theoretically illustrated by the first-principles density functional theory calculations, suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI. It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal …

Development Of Non-Precious Iron-Cobalt Alloy Catalyst For Electrocatalytic Reaction, Harsh Panchal

Electronic Theses & Dissertations

The development of a FeCo alloy catalyst with tunable Fe/Co ratios is examined to improve electrocatalytic performance in reactions like the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR). Many energy conversion devices, such as fuel cells, metal-air batteries, and water-splitting systems, depend on these interactions to function. These technologies have huge potential to meet the increasing need for hydrogen production and renewable energy sources worldwide, which are critical to attaining a sustainable energy future. When compared with noble metal-based catalysts, the FeCo alloy catalyst shows much higher catalytic activity, according to previous studies. Hydrothermal …

First-Principles Studies Of Electrical Polarization Effects In Ferroelectrics, Antiferroelectrics And Defects, Louis Alaerts

Dartmouth College Ph.D Dissertations

Over the last few decades, density functional theory (DFT) has emerged as a formidable tool in the field of computational material science. Not only has it become a complementary method approach to experiments by rationalizing the many complex properties of materials but its formidable predictive power can also be used to identify the most promising candidates for specific applications. Point defects in semiconductors have become an important platform for the development of quantum networks due to their ability to act as spin-photon interfaces. Spectral diffusion, the broadening of the optical emission line, can significantly impact the performance of these defect-based …

Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa

Journal of Materials Exploration and Findings

The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (p_{H₂S …}

The Evolution Of Nanoparticles In Nanoparticle Doped Optical Fibers, Mary Cahoon

All Dissertations

Optical fiber and fiber laser technologies based on silica glass are critical to many technologies today. One method to improve the optical performance of laser fibers is engineer the local environment around the active elements in the glass. To that end, this Dissertation focused on the fabrication and characterization of fibers made with nanoparticles incorporated into the glass to control the local composition. First, the nanoparticle composition and structure was analyzed as it evolved from from the initially-synthesized form to incorporation into the dense aluminum-silicate glass. The aluminum oxide in the glass was found to be important not only to …

Tailoring The Morphology Of Block Copolymers Via Solvent-Vapor Annealing, Bayleigh Madelin Loving

Honors Theses

Triblock polystyrene-polyisobutylene-polystyrene (PS-PIB-PS) copolymers have widespread applications from thermoplastic elastomers to protective coatings for ballistic applications. The incompatibility between the soft PIB and hard PS phases leads to phase separation and subsequent formation of morphological domains like lamellae and cylinders. The structures are stabilized by physical crosslinks, which can greatly improve the toughness of the triblock systems by preventing chain pullout during tensile deformation. We tailored the morphologies (achieving different morphologies with the same block copolymer) by changing the annealing conditions of the block copolymers. Solvent vapor annealing was used to selectively activate the mobility of a particular block, causing …

Mechanistic Investigation Of Ring-Opening Polymerization Of Polycaprolactone Using Tin(Ii) Catalysts: Ligand Effects And Biomedical Applications, Eva-Larue M. Barber

Honors Scholar Theses

This research explores the mechanistic aspects of ring-opening polymerization (ROP) of ε-caprolactone (CL) to produce polycaprolactone (PCL), a biodegradable polymer widely used in biomedical applications. The study investigates how light exposure and catalyst concentration influence polymerization efficiency, using tin(II) 2-ethylhexanoate [Sn(Oct)₂] as the catalyst in a non-polar toluene solvent at 90 °C. Reactions were conducted under either ambient light or black light bulb (BLB) illumination, with monomer-to-catalyst ratios of 1:1 and 200:1.

Proton nuclear magnetic resonance (¹H NMR) spectroscopy was used to analyze conversion efficiency by tracking the disappearance of monomer signals and appearance of characteristic PCL peaks. Results revealed …

Binary Solid/Liquid Equilibrium Of Mixtures Of Thermally Robust Salts And Molecular Compounds For Use As Heat Transfer Fluids, Jared Ridge Mathews

Honors Theses

Fossil fuels, contributors to climate change that may bear catastrophic consequences, power the entire world. The human species is almost entirely dependent on fossil fuels for energy, but other sources of renewable and environmentally friendly energy must be developed. Concentrated solar power (CSP) is a promising source of renewable energy with hampered potential—better heat transfer fluids (HTFs) are needed for it to be economically feasible. Currently, the HTFs in industrial use are predominantly either synthetic oils or nitrate-based molten salts. Synthetic oils are only stable up to 400 °C, and molten salts often have high melting temperatures, making them prone …

Electrocatalytic Nitric Oxide Reduction To Yield Ammonia Over Fe3C Nanocrystals, Sen Lin, Lang Zhang, Tong Hou, Jun-Yang Ding, Zi-Mo Peng, Yi-Fan Liu, Xi-Jun Liu

Journal of Electrochemistry

Nitric oxide (NO), which generally originates from vehicle exhaust and industrial flue gases, is one of the most serious air pollutants. In this case, the electrochemical NO reduction reaction (NORR) not only removes the atmospheric pollutant NO but also produces valuable NH₃. Hence, through the synthesis and modification of Fe₃C nanocrystal catalysts, the as-obtained optimal sample of Fe₃C/C-900 was adopted as NORR catalyst at ambient conditions. As a result, the Fe₃C/C-900 catalyst showed an NH₃ Faraday efficiency of 76.5% and an NH₃ yield rate of 177.5 μmol·h^–1·cm^{–2 …}

Ordering Degree Regulation Of Pt2Nico Intermetallics For Efficient Oxygen Reduction Reaction, Chen-Hao Zhang, Han-Yu Hua, Jun-Hao Yang, Qian Zhang, Chang Yang, De-Li Wang

Journal of Electrochemistry

Alloying transition metals with Pt is an effective strategy for optimizing Pt-based catalysts toward the oxygen reduction reaction (ORR). Atomic ordered intermetallic compounds (IMC) provide unique electronic and geometrical effects as well as stronger intermetallic interactions due to the ordered arrangement of metal atoms, thus exhibiting superior electrocatalytic activity and durability. However, quantitatively analyzing the ordering degree of IMC and exploring the correlation between the ordering degree and ORR activity remains extremely challenging. Herein, a series of ternary Pt₂NiCo intermetallic catalysts (o-Pt₂NiCo) with different ordering degree were synthesized by annealing temperature modulation. Among them, the o-Pt …

Performance Of Co2/H2O Co-Electrolysis In A Flat-Tube Solid Oxide Electrolysis Cell Stack Under Air-Free Environment, Xiao-Hui Zhong, Fei Wang, An-Qi Wu, Bei-Bei Han, Jian-Xin Wang, Wan-Bing Guan

Journal of Electrochemistry

This work investigates the transient performance and stability of CO₂/H₂O co-electrolysis in an air-free environment using a flat-tube solid oxide electrolysis cell (SOEC) stack. The results show that the transient behavior of the stack with and without blowing gas in the air electrode is almost the same. With a current density of 0.67 A·cm⁻²@750 °C, the stack operated for over 200 h under co-electrolysis conditions with no air blowing, and the voltage drop rate of the stack was approximately 0.203%/100 hours. Microstructure analysis reveals significant loss of Ni particles and formation of an insulating …

Variation Of Membrane Electrode Assembly Catalyst Layer In Unitized Regenerative Fuel Cell, Yollanda Nurcholifah, Dedi Rohendi, Edy Herianto Majlan, Nirwan Syarif, Addy Rachmat, Dwi Hawa Yulianti, Nyimas Febrika S

Journal of Electrochemistry

A unitized regenerative fuel cell (URFC) is a device that may function reversibly as either a fuel cell (FC) or water electrolysis (WE). An important component of this device is the Membrane electrode assembly (MEA). Therefore, this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers. This study measured Electrochemical Surface Area (ECSA), Electrochemical Impedance Spectroscopy (EIS), X-ray Diffraction analysis (XRD), and X-ray Fluorescence (XRF). Furthermore, the round-trip efficiency (RTE) of the MEA, as well as the performance in FC and WE mode, was measured. In comparison, The ECSA values of Pt-Ru/C …

Additive Manufacturing Of Thermoplastic Composites, Matik Heskin, K. Chandrashekhara, Richard Billo, Ming-Chuan Leu, Thomas P. Schuman

Miners Solving for Tomorrow Research Conference

No abstract provided.

Polymerization Methods For Vinyl Phosphonate Monomers: Challenges And Perspectives, Sara Mccauley

Miners Solving for Tomorrow Research Conference

No abstract provided.

Preliminary Assessment Of Non-Volatile Particulate Matter And Gaseous Emissions From A Premixed Pre-Vaporized Combustor Designed For Civil Supersonic Transport, Ugochukwu Ewuzie, Godwin Ifeanyi Ogbuehi, Steven Achterberg, Monday Uchenna Okoronkwo, Philip D. Whitefield

Miners Solving for Tomorrow Research Conference

No abstract provided.

Mechanochemical Reaction Kinetics—A Theoretical Modeling And Experimental Study, Maria Dolores Masso Ramirez

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanochemical reactions represent a class of chemical processes triggered by mechanical energy, widely recognized for their efficiency, solvent-free nature, and environmental benefits. They are increasingly applied in synthetic chemistry, a branch of science focused on creating new chemical compounds through controlled laboratory reactions. However, the mechanisms underlying mechanical activation remain poorly understood, primarily due to the difficulty in quantifying energy transfer during milling, where solid reactants are ground together using a ball mill. This thesis aims to bridge the gap in understanding the relationship between mechanical parameters and reaction kinetics by developing and validating a theoretical framework based on dimensional …