Engineering Commons^™

Evaluation Of Chromium-Crosslinked Amps-Hpam Copolymer Gels: Effects Of Key Parameters On Gelation Time And Strength, Maryam Sharifi Paroushi, Baojun Bai, Thomas P. Schuman, Yin Zhang, Mingzhen Wei

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Controlling CO₂ channeling in heterogeneous reservoirs remains a major challenge for both enhanced oil recovery (EOR) and secure geological storage. AMPS-HPAM copolymers exhibit high-temperature resistance and brine tolerance compared with conventional HPAM gels, making them well suited for the harsh environments associated with CO₂ injection. Chromium-based crosslinkers (CrAc and CrCl₃) were investigated because sulfonic acid groups in AMPS can coordinate with trivalent chromium ions, enabling dual ionic crosslinking and the formation of a robust gel network. While organic crosslinked AMPS-HPAM gels have been widely studied, the behavior of chromium-crosslinked AMPS-containing systems, particularly their gelation kinetics under …

Waveguide-Assisted Single-Mode Fiber Bragg Gratings In A Highly Multimode Coreless Fiber Via Femtosecond Laser Inscription For Extreme Temperature Quasi-Distributed Thermal Sensing, Farhan Mumtaz, Koustav Dey, Bohong Zhang, Jeffrey D. Smith, Ronald J. O'Malley, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This research reports a potential quasi-distributed thermal mapping optical sensing system for extreme temperatures, leveraging femtosecond (fs) laser inscribed single-mode fiber Bragg gratings (FBGs) and a waveguide within coreless, highly multimode optical fiber, resulting in a single-mode structure. Unlike doped single-mode fibers, coreless fibers composed of silica rods prevent issues associated with dopant migration and ensure data accuracy. The strategic placement of point-by-point FBGs in a cascaded formation on the fs-laser inscribed waveguide facilitates localized multipoint sensing. The long-term stability of the proposed waveguide-assisted FBG system was assessed over 24 hours at elevated temperatures (1000°C), showing no hysteresis during heating …

Evaluation Of A Novel Re-Crosslinkable Preformed Particle Gel For Conformance Control In Ultra-High Temperature Reservoirs, Yanbo Liu, Tao Song, Caleb Kwasi Darko, Thomas P. Schuman, Mingzhen Wei, Baojun Bai

Chemistry Faculty Research & Creative Works

Preferential fluid flow remains a major challenge in subsurface energy production and gas storage operations, resulting in excessive water production in mature oil fields, reduced heat extraction in geothermal reservoirs, and low sweep and storage efficiency in CO₂-EOR projects. Polymer gels are widely used to mitigate high-permeability channels; however, conventional systems exhibit limited plugging efficiency and short lifetimes in ultra-high-temperature reservoirs due to poor thermal stability. This study presents a novel ultra-high-temperature-resistant preformed particle gel (UHT-PPG) developed for conformance control in reservoirs with temperatures of 150–275 °C and severe super-K or channeling problems. The material was evaluated in …

Dietary Intake Of Micro- And Nanoplastics: Potential Adverse Gi Effects On Microbiome, Inflammation, And Neoplasia, Michael Saadeh, Gordon Hong, Sana Rabeeah, Priyata Dutta, Edward C. Oldfield, Iv, David A. Johnson

Department of Medicine Faculty Publications

Micro- and nanoplastics (MNPs) are pervasive in food-contact environments and the human diet, positioning the gastrointestinal (GI) tract as the primary portal of entry and a plausible site of early biological effects. Human exposure is supported by detection of microplastics in stool and colon tissue, and emerging clinical studies report associations between fecal microplastic burden and GI disease states, including inflammatory bowel disease (IBD) and colorectal cancer (CRC). Preclinical studies provide mechanistic plausibility, reporting that ingested MNPs can modulate microbial ecology, alter mucus membrane integrity, increase intestinal permeability through changes in cellular tight junction biology, and induce inflammatory gene expression. …

Effect Of Elemental Additions On The Microstructure, Macrostructure, And Mechanical Properties Of Gray Iron, August E. Rautmann

College of Graduate Studies: Theses & Dissertations

Gray iron is composed primarily of an iron matrix and flake graphite, with the higher percentage of volume taken up by the iron matrix. The iron matrix is the transformation product of austenite, and this prior austenite structure is understood to affect the final grain structure. Grain structure affects the properties of a metal, with a finer structure recognized as beneficial for most properties. Thus, the refinement of austenite structure has potential in improving the material properties of gray iron. This study aims to advance the limited knowledge about the control of austenite grain size via elemental additions. Building off …

Direct Ink Writing Of Shear Exfoliated Two-Dimensional Nanomaterial- Elastomeric Multifunctional Nanocomposite, Md Abdur Rahman Bin Abdus Salam, Asif Hasan Ridoy, A K M Abirul Haque, Muhammad Shahbaz Rafique, Md Arafat Hossain, Md Shahriar Forhad, Matthew G. Boebinger, Farid Ahmed, Karen Lozano, Ali Ashraf

Manufacturing & Industrial Engineering Faculty Publications

Direct ink writing (DIW) of polymer nanocomposites with high loadings of two-dimensional (2D) nanofillers (graphene and hexagonal boron nitride (hBN)) is challenging because of potential clogging, use of hazardous solvents, and agglomeration. Here, in this work, a shear exfoliation and sieving method to prepare DIW ink with high loading of nanofillers produced from low-cost bulk layered materials such as graphite and bulk hBN powder for successful DIW printing without the use of any solvents, binders, or plasticizers. The single-step exfoliation technique resulted in a composite with substantial layer reduction along the c-axis, as confirmed by SEM, TEM, XRD, and Raman …

Detecting And Repairing Conflicting Constraints In Co-Trained Physics-Informed Neural Networks For Composite Curing Processes, Cooper J. Evans

Dissertations, Master's Theses and Master's Reports

Composite materials have become a critical component of modern manufacturing, especially in the automotive and aerospace industries. The curing process for these composites has been modeled using a variety of partial differential equations representing the heat transfer and composite curing kinetics. Optimizing the applied temperature profile is critical for maximizing the efficiency and capacity of composite part manufacturers. Constraints must be placed on the inputs and outputs of the model, including but not limited to, the applied temperature profile, part temperature, and final degree of cure. Conflicting sets of constraints are easy to unknowingly impose due to the highly coupled …

Revisiting The Life Cycle Of Margalefidinium Polykrikoides Group Iii, Eduardo Pérez-Vega, Kenneth N. Mertens, Pjotr Meyvisch, Margaret R. Mulholland

OES Faculty Publications

Dinoflagellates produce cysts as a strategy to withstand environmental stressors, with nutrient depletion generally considered a key trigger for cyst production. Resting cysts are thick-walled, typically composed of one to several layers, and characterized by a prolonged dormancy period. In contrast, pellicle cysts possess a thin, single wall and exhibit no dormancy or a markedly shorter dormancy than resting cysts of the same species. Margalefidinium polykrikoides produces pellicle and resting cysts, whereas its congener, M. fulvescens, has been shown to produce pumpkin-like structures. Using phase-contrast microscopy, time-lapse microscopy, FlowCam, and attenuated total reflection Fourier transform infrared microspectroscopy (ATR μ-FTIR), …

Comparative Evaluation Of Gating Systems In Femnal Castings, K. Balasubramanian, Laura Bartlett, M. Xu

Materials Science and Engineering Faculty Research & Creative Works

To understand the efficiency of gating systems, four systems, namely AFS styled pressurized system, AFS styled non-pressurized system, naturally pressurized system with a side riser and a naturally pressurized system with a top riser, were studied. The naturally pressurized systems were provided with overflows which collected the incoming metal swirl while the pressurized and non-pressurized systems had runner wells. Parameters like velocity of metal flow, air entrapment, microporosity and Niyama criterion were considered, and a design was developed with a common pouring basin using solidification software. Two molds were 3D printed using carbonitride sand, and steel of composition Fe-29Mn-8.2Al-0.91C-0.88Si-0.49Mo was …

Overcoming Resolution Vs. Throughput Trade-Offs In Ceramic Material Extrusion Additive Manufacturing Via Viscoelastic Filament Stretching, Abid H. Rafi, David W. Lipke, Jeremy L. Watts, Gregory E. Hilmas, Ming C. Leu

Materials Science and Engineering Faculty Research & Creative Works

Fabricating large, monolithic ceramic parts using material-extrusion additive manufacturing remains challenging due to difficulty maintaining uniform moisture content during printing, which can lead to drying-induced defects such as warping and cracking, especially as part size and print time increase. Fabricated parts have trade-offs among print resolution, high throughput, and structural fidelity. Our study has shown that increasing the ratio of nozzle traverse speed vs. material extrusion speed increases filament stretching in viscoelastic ceramic paste, helping to overcome the trade-offs between resolution and throughput. Using aqueous ZrB2–SiC (70/30 vol.%) as a representative ultra-high temperature ceramic paste, rheological characterisation revealed viscoelastic yield-stress …

Raw Data For The Manuscript "Silicon-Stabilized Three-Dimensional Covalent Networks In High Entropy Diborides", Michael Yeung, Reza Mohammadi

Chemistry Department Faculty Scholarship

Abstract for data:

Raw data for the journal publication, Silicon-stabilized three-dimensional covalent networks in high entropy diborides. ReadMe file provided.

Abstract for Journal publication: 

High entropy ceramics offer a pathway to stabilize unconventional chemistries beyond traditional alloying rules. We report the incorporation of silicon into an AlB₂-type high entropy diboride, Cr_0.2Nb_0.2Si_0.2Ta_0.2Ti_0.2B₂, despite silicon violating classical Hume-Rothery rules for alloying. Arc melting produced a phase-pure, chemically homogeneous structure, as confirmed by powder X-ray diffraction (pXRD) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDS). Silicon occupies …

Multiphysics Modeling Of Melt Pool Dynamics And Powder Bed Stability In Lpbf Of Inconel 718 For A Circular Cavity, Nayan Pundhir, Oluwapelumi O. Adejumo, Kumbla Chandrashekhara, Joseph W. Newkirk, Heath Misak, Cesar Ortiz Rios

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser powder bed fusion (LPBF) is a metal additive manufacturing process in which a concentrated laser beam selectively melts successive powder layers to fabricate components. Final part quality is highly sensitive to process parameters such as hatch spacing, powder bed density, laser power, and scanning speed. In this study, a computational fluid dynamics model employing discrete element method has been developed in FLOW-3D to simulate LPBF of Inconel 718. The modeled powder bed incorporates particle size distribution data obtained from scanning electron microscopy and is evaluated for single-layer, single-track deposition over a circular cavity. The model captured melt pool dynamics …

The Effect Of Aluminum Substrate Surface Topography And Surface Energy On The Peel Strength Of Polyurethane Coatings, Christopher Ryan Grivers

Open Access Master's Theses

CUI information not included.

Peel Strength Of Polyurethane Coated Marine Metals In Air And In Underwater Environments, Maximillian Hill

Open Access Master's Theses

This study aims to characterize the hydrostatic peel strength of a hyperplastic material on three distinct and widely used marine-grade metals, using a primer. Aluminum 6061, HY-80 steel, and Nickel 400 (commonly known as Monel) are among the more popular metals used in the marine industry due to their unique material properties. To better understand the relationship of these materials and how we might quantify them, a peel test is performed at varying curing temperatures.

Following the investigation into varying curing temperatures, several specific marine environments will be considered. Submersible marine vehicles are designed to operate in a range of …

Field-Assisted Post-Processing Of Cold-Sprayed Pure Copper, Alan Hensley

Theses and Dissertations--Mechanical and Aerospace Engineering

The properties of materials processed through cold spray, and many other AM processes, are non-uniform and unpredictable. In most cases, post-processing is required to achieve desired properties and better uniformity. In cold spray, the typical method is an annealing heat treatment (AHT), which can improve bond strength, reduce porosity, and restore ductility, among other effects. AHT alone, however, is unable to completely remedy any of the unfavorable properties. In addition, long treatments at high temperatures are often needed for satisfactory results. This increases energy consumption and extends production times for products made by the process. For these reasons, numerous investigations …

Effects Of Gum Additives On Nickel Electroplating For Enhancing Steel Corrosion Resistance, Supitcha Supansomboon, Manatsawee Maneekan, Chanyanut Saenthaweesuk, Duangta Sitthichokcharoen, Natthapong Phinichka

Journal of Metals, Materials and Minerals

Low-carbon steels are widely used across various industries but have limited corrosion resistance, leading to safety hazards and a shortened service life. Nickel plating is a common method for enhancing steel corrosion resistance. The plating bath solution can be modified by adding additives to improve the properties of the coating. In this research, gum arabic, guar gum and gelatin were used as additives in a nickel electroplating bath. SS400 low-carbon steel, as a substrate, was plated with nickel from these different baths at 5 V for 25 min. Nickel coated with green additives showed higher hardness compared to those without …

Synergy Of Ground Granulated Blast-Furnace Slag And Limestone Powder In Ternary Cement: Effects On Heat Of Hydration And Strength Development, Pailyn Thongsanitgarn, Watcharapong Wongkeo, Thanongsak Nochaiya, Arnon Chaipanich

Journal of Metals, Materials and Minerals

This study explores the synergistic effect of ground granulated blast-furnace slag (GGBS) and limestone powder (LS) on the hydration behavior and mechanical performance of ternary cement systems. Calorimetry revealed that 30GGBS mix showed a significantly lower peak of about 2.3 mW∙g‒1 and a delayed response. In contrast, the incorporation of LS enhanced early hydration, with the 30LS mix reaching a peak of approximately 2.8 mW∙g‒1 around 6 h. Among ternary blends, 15GGBS–15LS exhibited the highest and earliest heat flow peak (about 2.55 mW∙g‒1 around 7.5 h), while 25GGBS–5LS showed a slower response (about 2.45 mW∙g‒1 around 9.5 h). Despite differences …

Degradation Of Wastewater By Advanced Oxidation Processes Using Green Synthesised Cuo Nanoparticles, Srinivasan Vishal, Anand Sarvesvaron, Muralidharan Keerthana, Hemanth Sanjay Reddy, A Babu Ponnusami

Journal of Metals, Materials and Minerals

This study highlights the green synthesis of CuO nanoparticles using coconut coir extract and evaluates their photocatalytic performance in the degradation of the Brown G dye. The CuO nano-particles were synthesised through sol-gel method, and the biomolecules like polyphenols, tannins and flavonoids acted as reducing agents to stabilise the nanoparticles. The characterisation of these nanoparticles was carried out through XRD, FTIR and FESEM methods. The nanoparticles were used to degrade the dye Brown G under UV irradiation.  Response surface methodology was used to optimise the operating parameter with Box-Behnken design, which is the most suitable for varying 3 or more …

Dual-Functional Activated Carbon From Coffee Grounds For Crystal Violet Dye Removal And Subsequent Application As An Electrode Material In Energy Storage Devices, Sirikorn Khaophong, Tawatchai Kangkamano, Sonchai Intachai, Panita Kongsune

Journal of Metals, Materials and Minerals

The conversion of agricultural waste into high-value functional materials offers a sustainable strategy to address environmental concerns. In this study, activated carbon was synthesized from spent coffee grounds (CGAC) via KOH activation and used for crystal violet (CV) dye adsorption. Under optimal conditions (0.5 g dosage, 300 mg∙L‒1 CV, 30°C, 120 min), CGAC achieved 91.41% removal efficiency, with adsorption behavior fitting pseudo-second-order kinetics and the Freundlich isotherm. Thermo-dynamic parameters confirmed a spontaneous and endothermic process. Moreover, the reusability study revealed that CGAC maintained a high removal efficiency above 88% after seven adsorption–desorption cycles, demonstrating its structural stability and potential for …

Investigation On The Tribological Properties Of Al2o3-Tic Substrates In Fixed Abrasive Lapping For Data Storage Applications, Benjie Locsing Fernandez, Thanakrit Srisuwan, Duangamol Tungasmita, Sukkaneste Tungasmita

Journal of Metals, Materials and Minerals

Alumina titanium-carbide (Al2O3-TiC) or simply AlTiC substrates were widely used in the magnetic recording industry for their superior mechanical and tribological properties. This study investigated the effect of AlTiC substrate crystal structure, chemical bonding and grain size in slider fix abrasive lapping tribology. Two types of AlTiC substrates, Type-A AlTiC and Type-B AlTiC equipped with an electro lapping guide (ELG), fully functional reader and writer devices were used in the study. The type-B lower material removal rate resulting to rougher surface finish was mainly due weakening caused by the titanium oxycarbide phase, which was the dominant factor, outweighing the minimal …

Surface Properties And In-Vitro Bioactivity Studies Of Tio2 Nanowire Doped Transition Metal (M=Fe, Co, And Mn), Misriyani Misriyani, Enayah Enayah, Z. Ryan Tian, Andi Meutiah Ilhamjaya

Journal of Metals, Materials and Minerals

This study investigates the influence of transition metal (Fe, Co, Mn) doping on the surface properties and in-vitro bioactivity of TiO2 nanowires. It aims to elucidate how transition-metal doping alters the surface behavior and biological response of TiO2 nanowires, enabling their potential use in biocompatible and magnetically responsive materials. Magnetic TiO2 nanowires doped with transition metals (Mx+/TiO2) were successfully prepared by a hydrothermal method using titanium dioxide in alkaline solution. Cations were added with Ti/Mx+ molar ratios of 5 to produce Fe/TNW, Co/TNW, and Mn/TNW. Characterization using SEM and XRD determine their surface properties. In-vitro bioactivity tests were conducted by …

Co-Sputtered Cuni Heteroatomic Electrocatalyst For Enhanced 5-Hydroxymethylfurfural Selective Electrochemical Conversion, Moumita Dikshit, Baleeswaraiah Muchharla, Luz Vazquez Rivera, Kapil Kumar, Sunita Sanwaria, Kishor Kumar Sadasivuni, Abdennaceur Karoui, Sandeep Kumar, Adetayo Adedeji, Bijandra Kumar

Civil & Environmental Engineering Faculty Publications

The electrochemical conversion of biomass-derived 5-hydroxymethylfurfural (HMF) represents a promising, economically viable, and environmentally sustainable approach for producing value-added chemicals using renewable energy and in situ hydrogen generated through water electrolysis. However, the electrochemical hydrogenation (ECH) of HMF remains challenging due to the inherently low catalytic activity and selectivity of the electrodes, compounded by competition with the kinetically favored hydrogen evolution reaction (HER) in aqueous electrolytes. In this work, we demonstrate that Cu_xNi_100-x heteroatomic thin films, fabricated via direct current (DC) magnetron co-sputtering, achieve a more than one order of magnitude increase in the HMF to 2,5-Bis-hydroxymethylfuran …

Distributed Temperature Sensing In The Spray-Cooled Shell Of A 150-Ton Dc Electric Arc Furnace Using Brillouin Optical Fiber Technology, Farhan Mumtaz, Yeshwanth Reddy Mekala, Koustav Dey, Rony Kumer Saha, Ogbole Collins Inalegwu, Manoj Kumar Pullagura, Bohong Zhang, Muhammad Roman, Nicholas Dionise, Zane Voss, Jeffrey D. Smith, Ronald J. O'Malley, Rex E. Gerald, Jie Huang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the deployment and validation of a Brillouin - distributed temperature sensing (DTS) system for real-time thermal monitoring of the spray-cooled upper shell of a 150-ton direct current Electric Arc Furnace (DC EAF) at Big River Steel Plant, Osceola, AR, USA. A four-channel Brillouin DTS system from OZ Optics was employed, with one active channel instrumented using an in-house-fabricated Brillouin scattering-depressed single-mode optical fiber (SMF28e+). The 60 m optical fiber sensor was fabricated, with 20 m allocated for thermal measurement and 40 m used as lead-in fiber to isolate the interrogator from the furnace environment. The fiber was …

The Efficacy Of Hybrid Manufacturing For High Stress Automotive Parts, Logan Trimmer

Harrisburg University Other Works

Presentation covering the broad strokes of the project. The goal was to prove the viability of hybrid/additive manufacturing for high stress automotive applications. This project focused on recreating a piston from an old engine to examine if hybrid manufacturing could be used for such applications. On a small scale, hybrid manufacturing was able to be more cost effective if the costs of the equipment and electricity were ignored. The decision to ignore those costs came from the inability to find accurate prices for industrial casting.

Buckling Analysis Of Auxetic Composite Laminates And Optimal Design Using Lamination Parameters And Machine Learning, Hans Bendon Maria Tamil Selvan

Mechanical and Aerospace Engineering Theses

Composite materials are widely used as structural panels in aerospace, automotive, and civil engineering applications, where buckling is often a critical failure mode. This thesis focuses on the analysis and design of composite laminates that maximize buckling performance under prescribed stiffness and thickness constraints.

The first part of the study investigates the buckling behavior of auxetic laminates, which exhibit a negative Poisson's ratio. While previous studies suggest that auxetic laminates can achieve higher critical buckling loads than non-auxetic laminates under simply supported boundary conditions with lateral restraint, the influence of other boundary conditions and plate aspect ratios has not been …

Charge‐Governed Mechanistic Evaluation Of Aav2 Clarification Via Functionalized Flat Sheet And Hollow Fiber Deconstructed Depth Filters, Mara Baughman‐Leach, Mattie Brock, Malgorzata Chwatko, Dibakar Bhattacharyya

Chemical and Materials Engineering Faculty Publications

The expansion of adeno-associated virus (AAV)-based therapeutics has increased the demand for efficient clarification. In this study, a functionalized deconstructed depth filtration platform was developed to dissect how membrane–virus charge, modulated by pH, influences separation. Three charge regimes, positive (pH 4), neutral (pH 6), and negative (pH 8) between the membranes and AAVs, were examined. The flat-sheet system, composed of sequential 1.2, 0.8, 0.45, and 0.1 µm membranes, enabled the first layer-by-layer analysis of depth filtration behavior. This revealed that Stage 1 and Stage 4 dominate clarification. Remarkably, substantial DNA capture (> 75%) was observed even in the largest-pore stage, …

Creep-Recovery Behavior Of Copper Springs At Low Stresses, Ming-Yen Tsai, Shou-Yi Chang, Yi-Chia Chou, Jyun-Lin Hu, Yulin Zhang, Fuqian Yang, Sanboh Lee

Chemical and Materials Engineering Faculty Publications

Copper springs, unlike conventional wires, endure complex stress states such as torsion and bending under sustained thermal and mechanical loads. This study examines the time-dependent creep-recovery behavior of copper springs under low tensile forces at temperatures ranging from 523 K to 623 K, focusing on springs with spring indexes (ratio of mean spring diameter to wire diameter) of 6.4, 8.5, and 9.6. The non-linear Burgers model with a Kelvin solid effectively captures the deformation response and mirrors dislocation nucleation and annihilation kinetics. SEM and TEM imaging reveal that low-angle grain boundaries (LAGBs) act as both dislocation sources and sinks. The …

Electron Beam Irradiation Effects On Bulk Metals: A Comparative Study Of Polycrystalline Versus Single-Crystalline Structures, A. A. Elmustafa, N. A. Sultana, A. H. Al-Allaq, M. Ojha, Y. S. Mohammed, J. Vennekate, H. Baumgart

Mechanical & Aerospace Engineering Faculty Publications

This study investigates the effects of electron beam (e-beam) irradiation on the mechanical and structural properties of eight bulk metallic samples, comprising both polycrystalline (PC) and single-crystalline (SC) forms of Ni, Cr, V, and Ti. These metals were evaluated as potential candidates for beam exit windows in high-power (MW-class) particle accelerators. The primary objective is to identify metals capable of withstanding the conditions of high-power/MW-class e-beam accelerators and serve effectively as exit windows. Selection criteria were based on each metal’s intrinsic properties, power dissipation capability, and irradiation-induced changes in mechanical behavior, including hardness, elastic modulus, and defect density. Comprehensive characterization …

Sulfhydryl-Functionalized Diarylethenes: Synthesis, Photoswitching, And Fluorescent Properties, Pramod Aryal, Jonathan Bietsch, Gowri Sankar Grandhi, Josh Choi, Guijun Wang

Chemistry & Biochemistry Faculty Publications

Sulfhydryl group (SH) plays important roles in reactions with various functional groups, especially in biologically active systems. Photoswitchable diarylethene (DAE) derivatives have demonstrated applications in many research fields. Among the many classes of diarylethene derivatives, thiol derivatives have not been extensively explored. In this study, we systematically synthesized and characterized a series of bis-thiol functionalized dithienylethene derivatives. The thiol groups in this series are attached directly to the thiophene, or through a phenyl or methylene linker. Each series incorporated both dithienyl cyclopentene and hexafluorocyclopentene bridges and total six thiol substituted diarylethenes were synthesized. Among the six sulfhydryl DAE derivatives, four …

Multidentate Surfactant-Dependent Synthesis Of Giant Iridium Superstructures, Ramjee Balasubramanian, Maeren E. Hill

Chemistry & Biochemistry Faculty Publications

Giant superstructures of iridium, comprised of smaller spherical and slightly larger anisotropic nanoparticles, were synthesized by reducing iridium chloride in the presence of resorcinarene, a class of tetrameric macrocyclic polyphenols, with sodium borohydride in ethanol in 30 min under mild conditions. These superstructures were characterized by a range of techniques including TEM, HRTEM, EDS and other spectroscopic methods. The impact of the macrocyclic surfactant, its features and reaction conditions in dictating the formation of giant iridium superstructures was evaluated. The packing density of nanoparticles in these giant iridium superstructures could be altered qualitatively by varying the duration of the reaction, …