Materials Chemistry Commons^™

Mediating Energy And Charge Transfer Dynamics Of Lead Halide Perovskite Nanocrystals Via Surface Chemical Approaches, Aaron S. Malinoski

Dissertations, Theses, and Capstone Projects

Energy and charge transfer are the fundamental mechanisms by which semiconductor nanocrystals interact with their external environment and underpin all light-conversion related applications. Lead halide perovskite nanocrystals (PNCs) are a relatively new class of semiconductor nanocrystals that possess a unique and dynamic surface chemical environment. Investigations into the influence of these surface chemical conditions on the electronic coupling between surface-bound molecular acceptors and the perovskite nanocrystals, and how the surface chemistry can be manipulated, in turn controlling the charge and energy transfer mechanisms, is the focus of this dissertation. Through ligand-shell engineering using commercially available, inexpensive small molecules, the surface …

Monosaccharide Binding To Synthetic Carbohydrate Receptor Microarrays, Milan A. Shlain

Dissertations, Theses, and Capstone Projects

Chapter 1: A glycan detection platform comprised of synthetic carbohydrate receptors (SCRs) immobilized onto polymer brushes was prepared. SCR043, an alkene-containing SCR, was incorporated into grafted-from polymer brushes using hypersurface photolithography, resulting in microarrays of SCR043-functionalized polymer brushes, where brush height (h) and SCR grafting density (Γ) is controlled precisely at each feature in the array. The influence of h and Γ on the binding to five fluorescently labelled monosaccharides – α-glucose (α-Gluc-FL), α-galactose (α-Gal-FL), α-mannose (α-Man-FL), β-glucose (β-Gluc-FL), and β-galactose (β-Gal-FL) – in aqueous buffer …

The Role Of Water In Peptide Behavior And Peptide-Based Water-Responsive Crystals, Janel Jannette Rivera Cancel

Dissertations, Theses, and Capstone Projects

Water plays a crucial role in shaping the behavior and function of biomolecules across the liquid, supercooled, and glassy states. This thesis presents a dual approach combining computational simulations and experimental investigations to explore the influence of water on biomolecular systems, particularly peptide-based materials. We employ molecular dynamics simulations to study the hydration-dependent structural dynamics of homopolymer peptides. Simulations were carried out across a range of temperatures and pressures to analyze changes in hydration and structural stability, shedding light on the behavior of peptides under supercooled and glassy conditions. These studies are especially relevant for understanding biomolecular stability in cryopreservation. …

Structural, Electronic And Magnetic Properties Of Vanadium Doped Transition Metal Dichalcogenides (Tmds), Qudsia Ashraf

Dissertations, Theses, and Capstone Projects

Magnetic semiconductors are a prerequisite for spintronic devices but their ferromagnetism disappears at room-temperature hindering application in room temperature electronic devices. Enormous research has been conducted on the room-temperature ferromagnetic order in monolayer form of bulk van der Waals materials but the few layer system has not been extensively explored.

Doping is an effective approach to modulate the structural, electronic and magnetic properties of two-dimensional (2D) Transition metal dichalcogenides (TMDs) and expand their application. The effect of vanadium dopant on structural, electronic and magnetic properties of Tungsten Diselenide (WSe₂) was studied by X-ray Photoelectron Spectroscopy (XPS), Atomic Force …

Rational Design Of Peptide-Based Materials Informed By Multiscale Molecular Dynamics Simulations, Dhwanit Rahul Dave

Dissertations, Theses, and Capstone Projects

The challenge of establishing a sustainable and circular economy for materials in medicine and technology necessitates bioinspired design. Nature's intricate machinery, forged through evolution, relies on a finite set of biomolecular building blocks with through-bond and through-space interactions. Repurposing these molecular building blocks requires a seamless integration of computational modeling, design, and experimental validation. The tools and concepts developed in this thesis pioneer new directions in peptide-materials design, grounded in fundamental principles of physical chemistry. We present a synergistic approach that integrates experimental designs and computational methods, specifically molecular dynamics simulations, to gain in-depth molecular insights crucial for advancing the …

Biomolecular Crystals As Functional Materials, Fahmeed Khan Sheehan

Dissertations, Theses, and Capstone Projects

The field of supramolecular chemistry has undergone significant evolution over the last few decades, progressing from fundamental studies of self-assembling systems to the rational design of functional materials with exceptional properties. Among these materials, short peptides have emerged as a chemically simple yet highly versatile class of biomimetic compounds. Initially, short peptides were used as model systems to understand larger protein interactions. As the field progressed, short peptides were found to have exceptional functionality, and are now explored as functional nanomaterials for diverse applications. In many cases, short peptide materials have displayed properties not found in biology, in some cases …

Synthesis And Characterization Of Polymer-Based Complex Nanomaterials, Prashun G. Roy

Dissertations, Theses, and Capstone Projects

The original research work in this dissertation is about the use of polymers in two significantly important areas. One involves creating mesoporous silica materials with various morphologies using a mixed Pluronic surfactant system made up of two poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) surfactants, one of which contains long hydrophilic (PEO) blocks and the other has a significantly higher proportion of hydrophobic PPO . In addition, a glucose responsive core-shell type microgel was also developed for shifting the glucose responsive volume phase transition by using polymeric nanomaterials.

Chapter 1 of the dissertation discussed some historical background of synthesis and uses of …

Construction And Performance Optimization Of Bioconjugated Nanosensors For Early Detection Of Breast Cancer And Pro-Inflammatory Diseases, Pooja Gaikwad

Dissertations, Theses, and Capstone Projects

In recent years, nanosensors have emerged as a tool with strong potential in medical diagnostics. Single-walled carbon nanotube (SWCNT) based optical nanosensors have notably garnered interest due to the unique characteristics of their near-infrared fluorescence emission, including tissue transparency, photostability, and various chiralities with discrete absorption and fluorescence emission bands. Additionally, the optoelectronic properties of SWCNT are sensitive to the surrounding environment, which makes them suitable for in vitro and in vivo biosensing. Single-stranded (ss) DNA-wrapped SWCNTs have been reported as optical nanosensors for cancers and metabolic diseases. Breast cancer and cardiovascular diseases are the most common causes of death …

Sers For The Detection Of Trace Materials, Omari Kirkland

Dissertations, Theses, and Capstone Projects

In this dissertation are presented three projects that contribute to the body of research on SERS in the forensic, heritage, and semiconductor fields. The first project, Charge-Transfer mapping on GaN/Ag, a silver-decorated nanopillar semiconductor substrate fabricated from the GaN is used with the Raman probe Rhodamine 6 G (R6G) to map the effect of the nanofeatures on the CT resonance. The second project, in collaboration with Marco Leona from the Metropolitan Museum of Art, explores the use of AgNIFs to identify colorants used on textile fiber samples from four 19th century works of Japanese art. The final project analyzes the …

Design And Applications Of Fmoc-Histidine And Aspartic Acid Tripeptides As Proton Conductive Materials, Shejla S. Pollozi

Dissertations, Theses, and Capstone Projects

The increasing demand for clean and sustainable energy has driven forward rapid improvements in polymer-electrolyte fuel cells and the use of ion-conducting polymers (ionomers) as proton exchange membranes and catalyst binders. While perfluorinated electrolytes have been commercially used as conductive membranes for nearly four decades, a new class of sustainable, conductive materials has emerged, inspired by the efficiency of charge transport processes in biological systems. These molecules, knows as peptide amphiphiles (PAs), have gained popularity as building blocks for the bottom-up fabrication of nanomaterials through supramolecular self-assembly. Supramolecular nanostructures, often in the form of hydrogels, are held together via non-covalent …

Nanoscale Imaging Of Electrocatalytic Nanomaterials By High-Resolution Scanning Electrochemical Microscopy, Xiang Wang

Dissertations, Theses, and Capstone Projects

Numerous insights of the structure–electrochemical activity relationship of nanocatalysts have been obtained by using macroscopic electrochemical measurements over the last several decades. However, signals measured by large electrodes are inevitably averaged out of many nanocatalysts, non-uniformed sizes, uneven morphologies, and multiple crystallographic facets. Over the last ten years, Scanning Electrochemical Microscopy (SECM) has advanced electrochemical measurements toward micro- to nanoscale level at a high spatial resolution. The advantages of using nanoelectrode in SECM include fast mass transfer of reactive species, dominated radial diffusion pattern, small double layer capacitance and small RC constant. In this thesis, high-resolution SECM is applied to …

Engineered Plga Nanofibers For Drug Delivery, Andrew Mancuso

Dissertations, Theses, and Capstone Projects

Poly-lactic-co-glycolic acid (PLGA) polymers are rapidly gaining momentum as a platform for next-generation drug delivery systems due to their ease and low cost of synthesis, favorable biocompatibility and biodegradability, and lack of toxicity. In particular, the application of drug-loaded PLGA nanofibers directly to a target tissue may represent a promising alternative to traditional routes of drug administration (e.g., oral, injectable) as they offer the potential to greatly improve bioavailability, increase efficacy, and reduce off-target toxicity. Furthermore, the use of such a system may potentially allow for greater flexibility in clinical drug development, by enabling the use of compounds which have …

Synthesis And Biomedical Applications Of Hollow Iron Oxide Nanoparticles, Aloka S. Paragoda Arachchilage

Dissertations, Theses, and Capstone Projects

Nano-scale materials have gained much attention during the past few decades due to the stark differences in their properties compared to bulk material. Thus, they are being studied for a myriad of applications ranging from harnessing solar energy to diagnostics. This thesis focuses on the synthesis of hollow iron oxide nanoparticles using Galvanic replacement reactions and their application in drug delivery. Moreover, the use of a peptide precursor for the enhancement of exosomes is also discussed.

Chapter 1 discusses a simple and economical Galvanic approach used for the synthesis of hollow one-dimensional iron oxide nanotubes. In the initial reaction, the …

Sensitized Photooxidation Of Prenylated Compounds: Mechanisms Of Downstream Dark Effects And Phototoxicity Priming, Shakeela Jabeen

Dissertations, Theses, and Capstone Projects

This thesis consists of four chapters as detailed below.

Chapter 1 discusses a singlet oxygen priming mechanism. Airborne singlet oxygen derived from photosensitization of triplet dioxygen is shown to react with an alkene surfactant (8-methylnon-7-ene-1 sulfonate) leading to ‘ene’ hydroperoxides that in the dark inactivate planktonic E. coli. The ‘ene’ hydroperoxide photoproducts are not toxic on their own, but they become toxic after the bacteria are pretreated with singlet oxygen. The total quenching rate constant (k_T) of singlet oxygen of the alkene surfactant was measured to be 1.1 × 10⁶ M⁻¹ s^{− …}

Visible Light Photocatalysis Of Organic Reactions In H2o, Sankarsan Biswas

Dissertations, Theses, and Capstone Projects

Visible-light photocatalysis in H₂O provides an attractive, green alternative to typical organic synthesis, which often involves toxic solvents, metal catalysts, and large energy demands. Hence, there is a growing need for an efficient photocatalytic methods that use either aqueous media as a solvent or can proceed solvent-free. However, commercially available photocatalysts do not work well for aqueous photocatalysis. Supramolecular systems in particular have been explored recently to address these issues associated with aqueous photocatalysis. Chapter 1 will review recent advances in aqueous supramolecular photocatalysis with examples of different supramolecular systems and how they have addressed some of the …

Application Of Peo-Ppo-Peo Triblock Copolymers In Synthesis Of Silica And Organosilica Nanomaterials, Shu Zhang

Dissertations, Theses, and Capstone Projects

In this dissertation, the research work focused on the application of Pluronic triblock copolymers, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO), in the synthesis of mesoporous material, such as double-helical silica nanotube structures as well as bridged organosilica nanotubes by using swollen micelles of Pluronic surfactants and their mixtures. Chapter 1 introduced the background and several important mesoporous structures, and the relevant topics in this dissertation, such as, silica nanotubes, helical silica nanotubes, silica vesicles and organosilica nanotubes. Chapter 2, continued research works from earlier published paper (ACS Nano 2021, 15, 1016-1029), discussed static treatment and stirring effect on the formation of …

Engineering Rare-Earth Based Color Centers In Wide Bandgap Semiconductors For Quantum And Nanoscale Applications, Gabriel I. López-Morales

Dissertations, Theses, and Capstone Projects

For many years, atomic point-defects have been readily used to tune the bulk properties of solid-state crystalline materials, for instance, through the inclusion of elemental impurities (doping) during growth, or post-processing treatments such as ion bombardment or high-energy irradiation. Such atomic point-defects introduce local ‘incompatible’ chemical interactions with the periodic atomic arrangement that makes up the crystal, resulting for example in localized electronic states due to dangling bonds or excess of electrons. When present in sufficient concentrations, the defects interact collectively to alter the overall bulk properties of the host material. In the low concentration limit, however, point-defects can serve …

Growth, Optimization, And Characterization Of Topological Insulator Nanostructures By Molecular Beam Epitaxy, Ido Levy

Dissertations, Theses, and Capstone Projects

Topological insulators (TIs) have been the subject of much research since their discovery in 2009. The unique band structure of the TIs makes them attractive in research of exotic physical phenomena, such as the realization of the quantum anomalous Hall effect, as well as novel applications, including quantum computing, spintronics, and more. From a crystal growth perspective, their van-der-Waals structure also provides new opportunities, for example, by enabling the growth on a large selection of substrates. This thesis presents the growth of three-dimensional TI layers, heterostructures and magnetic TIs by molecular beam epitaxy (MBE). First, we show the improvement of …

Biomimetic And Medical Applications Of Hollow Nanoscale Structures, Justin Fang

Dissertations, Theses, and Capstone Projects

Materials whose structure incorporates nanoscale void spaces have multiple possible uses, whether in a bulk form or as individual particles, due to the combination of high surface area ratios and nanoscale material properties. This thesis will explore a few of these possibilities, concentrating on potential biomimetic and biomedical applications, for two materials: metal- organic frameworks and superparamagnetic iron oxide nanocages.

Metal-organic frameworks consist of metal ions such as Cu2+ which have highly porous lattice structures allowing them to absorb and release guest molecules such as peptides like diphenylalanine; this stored chemical energy can be turned into kinetic energy and used …

Development Of Optical Nanomaterial For Enhanced Cerenkov Imaging, Qize Zhang

Dissertations, Theses, and Capstone Projects

Cancer is a significant public health problem worldwide and is the second leading cause of death in the United States. Imaging has increasingly been used over the last two decades to improve the diagnosis and guidance of tumor tissue removal surgery. Among the most widely used techniques for in vivo imaging are planar and tomographic fluorescence imaging and bioluminescence imaging. Despite their utility, these techniques are primarily restricted to preclinical use. Factors that have prevented translation from the bench to the bedside include depth-penetration considerations, regulatory issues, and toxicity. A recent development in nuclear imaging has been the ability to …

Enhanced Platinum (Ii) Drug Delivery For Anti-Cancer Therapy, Marek T. Wlodarczyk

Dissertations, Theses, and Capstone Projects

Over the years, anti-cancer therapies have improved the overall survival rate of patients. Nevertheless, the traditional free drug therapies still suffer from side effects and systemic toxicity, resulting in low drug dosages in the clinic. This often leads to suboptimal drug concentrations reaching cancer cells, contributing to treatment failure and drug resistance. Among available anti-cancer therapies, metallodrugs are of great interest. Platinum (II)-based agents are highly potent and are used to treat many cancers, including ovarian cancer (OC). Cisplatin (cis-diaminedichloroplatinum (II)) is the first Food and Drug Administration (FDA)-approved metallodrug for treatment of solid tumors, and its mechanism …

Molecular Dynamics Simulations Of Self-Assemblies In Nature And Nanotechnology, Phu Khanh Tang

Dissertations, Theses, and Capstone Projects

Nature usually divides complex systems into smaller building blocks specializing in a few tasks since one entity cannot achieve everything. Therefore, self-assembly is a robust tool exploited by Nature to build hierarchical systems that accomplish unique functions. The cell membrane distinguishes itself as an example of Nature’s self-assembly, defining and protecting the cell. By mimicking Nature’s designs using synthetically designed self-assemblies, researchers with advanced nanotechnological comprehension can manipulate these synthetic self-assemblies to improve many aspects of modern medicine and materials science. Understanding the competing underlying molecular interactions in self-assembly is always of interest to the academic scientific community and industry. …

Tools And Strategies For The Patterning Of Bioactive Molecules And Macromolecules, Daniel J. Valles

Dissertations, Theses, and Capstone Projects

Hypersurface Photolithography (HP) is a printing method for fabricating structures and patterns composed of soft materials bound to solid surfaces and with ~1 micrometer resolution in the x, y, and z dimensions. This platform leverages benign, low intensity light to perform photochemical surface reactions with spatial and temporal control of irradiation, and, as a result, is particularly useful for patterning delicate organic and biological material. In particular, surface- initiated controlled radical polymerizations can be leveraged to create arbitrary polymer and block- copolymer brush patterns. Chapter 1 will review the advances in instrumentation architectures from our group that have made these …

Synthesis, Characterization And Applications Of Europium Based Perovskite Oxide Nanoparticles, Nasim Farahmand

Dissertations, Theses, and Capstone Projects

The synthesis and characterization of nanocrystalline transition and rare-earth metal oxides have been studied widely over the past years. These materials possess unique physical, chemical, magnetic and dielectric properties which make them potential candidates for a wide range of applications such as electronics, energy storage and photocatalysis. There are a number of synthesis methods for preparing these materials, where most of them require stringent conditions such as high pressure and high temperature. However, in this study, a modified sol-gel synthesis has been used with a lower calcination temperature to make uniform nanocrystals of the transition/rare-earth metal oxide family. The focus …

Interactions Of Organic Fluorophores With Plasmonic Surface Lattice Resonances, Robert J. Collison

Dissertations, Theses, and Capstone Projects

It is common knowledge that metals, alloys and pure elements alike, are lustrous and reflective, the more so when a metal surface is flat, polished, and free from oxidation and surface fouling. However, some metals reflect visible light, in the 380 nm to 740 nm range of wavelengths, much more strongly than others. In particular, some metals reflect wavelengths in certain portions of the ultraviolet (UV), visible, and near-infrared (NIR) regime, let us say 200 nm to 2000 nm, while absorbing light strongly in other segments of this range. There are several factors that account for this difference between various …

Peo-Ppo-Peo Surfactant Mixtures As Templates For Silicas With Very Large Cylindrical Mesopores At Ambient Temperature And With Helical Mesopores At Sub-Ambient Temperature, Laurance Beaton

Dissertations, Theses, and Capstone Projects

The original research described herein concerns the synthesis of mesoporous silicas through a surfactant-templating method. The approach taken involved the use of a mixed surfactant system of two poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) surfactants, with one of the copolymers containing a much larger percentage of hydrophobic (PPO) blocks than the employed co-surfactant. Systematic adjustments of experimental parameters initially enabled the preparation of 2-D hexagonally ordered mesoporous silicas (SBA-15) of uncommonly large pore diameter at ambient temperature. Comparable silica was synthesized with and without temperature control. Additional adjustments to experimental parameters, including reduction of the relative amount of framework precursor used in …

Excitons In Self-Assembled Hybrid Systems Of Molecular Aggregate Light-Harvesting Nanotubes: Charge-Transfer Substrates And Solution-Stabilized Nanocomposites, Kara Ng

Dissertations, Theses, and Capstone Projects

Delocalized Frenkel excitons-coherently-shared excitations among chromophores-are responsible for the remarkable effciency of supramolecular light-harvesting aggregates within photosynthetic organisms. Despite tremendous progress towards a deeper understanding of these photosynthetic complexes, as well as progress in the development of organic solar cells, the possibility of using bio-inspired molecular nanostructures for large-scale solar energy conversion has not been realized yet. The persistent limitations in translating natures design principles for applications in optoelectronic devices have been the supramolecular structures fragility, and the Frenkel excitons delicate nature. The structural instability, both dis-assembly and spontaneous re-assembly of aggregates. Analysis of the absorption spectrum of a model …

The Reduction, Sequestration, And/Or Coordination Of Technetium-99 Utilizing Polyoxometalates And Nanomaterials, Colleen Mb Gallagher

Dissertations, Theses, and Capstone Projects

Research into the sequestration of radionuclides from aqueous media is being conducted due to the contamination of aqueous waste effluents and groundwater with highly toxic long-lived radionuclides. These contaminants are introduced into water and streams from legacy nuclear sites, nuclear reactor operations, nuclear fuel reprocessing, nuclear weapons testing, and plutonium production. A major contributor (~6%) to the waste from thermal neutron fission of uranium-235 is the radionuclide technetium-99 (⁹⁹Tc). It is considered a long-lived radioisotope with a half-life of 2.1x10⁵ years. It is a weak beta emitter with a max energy of 0.29 MeV and is most …

Minimalistic Peptide-Based Supramolecular Systems Relevant To The Chemical Origin Of Life, Daniela Kroiss

Dissertations, Theses, and Capstone Projects

All forms of life are based on biopolymers, which are made up of a selection of simple building blocks, such as amino acids, nucleotides, fatty acids and sugars. Their individual properties govern their interactions, giving rise to complex supramolecular structures with highly specialized functionality, including ligand recognition, catalysis and compartmentalization. In this thesis, we aim to answer the question whether short peptides could have acted as precursors of modern proteins during prebiotic evolution. Using a combination of experimental and computational techniques, we screened a large molecular search space for peptide sequences that are capable of forming supramolecular complexes with adenosine …

Synthesis And Characterization Of Multifunctional Transition Metal Oxide Nanoparticles Through A Modified Sol-Gel Method With Application In Energy Storage, Julien Lombardi

Dissertations, Theses, and Capstone Projects

The Synthesis of transition metal oxide nanoparticles has been studied in great detail over the many years. The most studied transition metal oxide nanoparticles are perovskites of the ABO₃ stoichiometry (A and B = transition metal) and more recently double perovskite crystal structures of the AA’BO₆ or A₂BB’O₆ stoichiometry due to the many different properties arising from the many different combinations of elements possible. These materials have proven potentially useful in many fields, but due to properties such as ferroelectricity and ferromagnetism, the desire to integrate these materials into electronics is ever growing. Many synthesis …