Materials Chemistry Commons^™

Probing The Gelation Phenomena In Molecular And Seed-Based Gels, Malick Samateh

Dissertations, Theses, and Capstone Projects

The interest in molecular gels has been gaining momentum as evident from being developed for a broad spectrum of applications. This impetus stems from several reasons that include: (i) molecular gels are highly stimuli responsive as they easily respond to thermodynamic changes, disintegrating into well-defined chemicals/building blocks because of the purely physical (in contrast to chemically cross-linked) nature of the interactions holding their 3D networks together; (ii) the sheer abundance of simple small molecules to choose starting materials from and the vast potential of tunability of the low molecular weight gelators (LMWGs) make the LMWGs and the molecular gels highly …

Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites, Frederick A. Pearsall

Dissertations, Theses, and Capstone Projects

Nanocrystalline transition metal oxides with unique chemical, physical, magnetic and dielectric properties have very broad applications, ranging from photocatalysis, capacitor energy storage and 4-state memory. Frequency stable, high permittivity nanocomposite capacitors produced under mild processing conditions offer an attractive replacement to MLCCs derived from conventional ceramic firing. In one project reported herein, 0-3 nanocomposites were prepared using BaTiO₃ (barium titanate, BTO) nanocrystals, suspended in a poly(furfuryl alcohol) matrix, resulting in a stable, high effective permittivity, low and stable loss dielectric. Effective medium approximations were used to compare this with similar nanocomposite systems. The use of synthesized BTO nanocrystal photocatalysts …

Mild Synthesis Of Perylene Tetracarboxylic Monoanhydrides With Potential Applications In Organic Optoelectronics, Xizhe Zhao

Dissertations, Theses, and Capstone Projects

Perylene tetracarboxylic derivatives are considered good n-type semi-conductors. In past decades, there has been extensive study on their synthesis and electronic properties. Because of the high electron affinity, the ability to form π-π stacks, they have been widely utilized in organic photovoltaic solar cells, field-effect transistors and light-emitting diodes. Many of those applications prefer unsymmetrically substituted perylene tetracarboxylic derivatives. Perylene monoanhydrides are the most versatile intermediates for the preparation of unsymmetrically substituted perylene tetracarboxylic derivatives. In this thesis, I focused on introducing new synthesis methods for perylene monoanhydrides with labile functional group and their potential applications in organic optoelectronics.

In …

Peptide Mediated Co-Assembly Of Porphyrin: Towards Sustainable Biomaterials For Light Harvesting And Catalysis, Wsm Nadeesha K. Wijerathne

Dissertations, Theses, and Capstone Projects

The diverse molecular functions of naturally occurring biomaterials designed from proteins are fundamentally based on a set of conserved building blocks, namely the 20 gene coded amino acids. The supramolecular structures and functions of proteins dictates by the self-assembly, where the complexity of proteins arise from a large number of amino acids. Generation of biomimetic systems that resemble the structures and functions of proteins is of great interest yet challenging due to the tremendous complexity of the natural systems. It is important to investigate alternative strategies to design much simpler systems that exhibit the same or similar function as proteins. …

Raman And Surface Enhanced Raman Spectroscopy For Forensic Analysis: Case Studies On The Identification Of Illicit Substances And Artist Pigments, Abed Haddad

Dissertations, Theses, and Capstone Projects

Raman spectroscopy is an effective tool for detecting trace amounts of material by fingerprint-like vibrational spectra. At times, the weak intensity of Raman scattering can make it difficult to distinguish trace materials. This shortcoming is addressed by surface‐enhanced Raman spectroscopy (SERS), which produces strong signal enhancements when target compounds are near metal nanoparticles. For the first part of this thesis, the identification of fentanyl and carfentanil, main culprits in the opioid epidemic, was done using normal Raman and the SERS spectroscopy. As an aid in the assignment of the spectral lines, a computational model was built using Density Functional Theory …

Iron Oxide Nanomagnets In Polymer Matrices – Synthesis And Characterization, Shenjie Qiu

Dissertations, Theses, and Capstone Projects

Magneto-responsive polymer-iron oxide materials have been fabricated by coating various polymers on iron oxide nanoparticles (NPs). The stability of magneto-responsive polymer-iron oxide materials relies on the selection of appropriate coating anchors, such as catechols and silanes. This dissertation describes two robust polymer coating systems on iron oxide NPs. One system focuses on thermo-responsive nitrated catechol-N-isopropylacrylamide polymers with binding enhancement factors (EnF) of ~40 and ~20 towards iron oxide NPs and a boronic acid compared to the polymers without the nitro group. The second system involves coating of poly(vinyl alcohol) (PVA) on iron oxide NPs via a silane anchor …

Nmr Characterizations Of Candidate Battery Electrolytes, Stephen A. Munoz

Dissertations, Theses, and Capstone Projects

Enormous strides have been made in next-generation power sources to build a more sustainable society. Energy storage has become a limiting factor in our progress, and there are huge environmental and financial incentives to find the next step forward in battery technology. This work discusses NMR methods for characterizing materials for use in battery application, with a special focus on relaxometry and diffusometry. Examples are provided of various recent investigations involving novel candidate electrolyte materials with different collaborators. Works discussed in this thesis include: the characterization of a new disruptive solid polymer electrolyte technology, investigations of the dynamics of super …

Nanoporous Carbon-Based Co2 Reduction Catalysts: Exploring The Combined Effects Of Surface Chemistry And Porosity, Wanlu Li

Dissertations, Theses, and Capstone Projects

For the first-time sulfur-doped, nitrogen-doped and sulfur, nitrogen-codoped nanoporous carbons were systematically studied as catalysts for CO₂ electrochemical reduction reaction (CO₂ERR). The Faradaic efficiencies (FE) of CO and CH₄ formation were calculated to evaluate the performance of these carbons. The best catalysts showed the FE of CO and CH₄ formation of 29% and 0.76%, respectively. It was found that the overall performance in CO₂ERR dramatically increased upon the reduction pretreatment of the carbons in N₂-saturated electrolyte before the CO₂ reduction process. The pretreated carbon showed the maximum FE of CO …

Toxic Gas Sensing On Nanoporous Carbons, Nikolina-Eleni Travlou

Dissertations, Theses, and Capstone Projects

Activated carbons, either synthetic, developed in our laboratory, or commercial, were prepared or further modified, in order to introduce specific heteroatoms such as oxygen, nitrogen and sulfur to their matrices. Chips coated with thin layers of the carbon samples were used for the sensing of gaseous ammonia. They were exposed to continuous cycles of various ammonia concentrations (10-500 ppm), and changes in normalized resistance were analyzed. In all cases linear responses were recorded and the chips reached sensitivities as high as 31%, which are comparable to those of modified graphene-based sensors. The applied specific surface chemical modifications were an effective …

Heterojunction Engineering For Next Generation Hybrid Ii-Vi Materials, Thor Garcia

Dissertations, Theses, and Capstone Projects

Molecular Beam Epitaxy(MBE) is a versatile thin film growth technique with monolayer control of crystallization. The flexibility and precision afforded by the technique allows for unique control of interfaces and electronic structure of the films grown. This facilitates the realization of novel devices and structures within a research environment normally only achieved though complex industrial processes. In the past, the control of each interface in MBE has been explored to great benefit. In this work, we study the control of these interfaces so as to increase the performance of novel devices material systems. This dissertation focuses on two main areas …

Naturally-Derived Molecular Ensembles In Medicine, Materials Science And Evolutionary Biology: An Interdisciplinary Study, Silvio Panettieri

Dissertations, Theses, and Capstone Projects

The first chapter will introduce the work carried out in collaboration with the Govind laboratory at CCNY. Our quest was set forth to investigate the intimate relationship lying between chronic inflammation and tumor development. For at least the last fifteen years much research has been conducted on this topic; yet, the level of complexity arising from exceedingly interwoven biochemical pathways in mammals has resulted in slow advancements in this field. This is why we resorted to a simple yet powerful immunogenetic model organism, the fruit fly Drosophila melanogaster, in combination with the administration of the most common anti-inflammatory drug, …

Chelating Ligands And Nanomaterials Based On Graphene Oxide For The Reduction And Sequestration Of Radiometals And Protein Purification, Sam Groveman

Dissertations, Theses, and Capstone Projects

Nuclear waste remediation and protein purification using immobilized metals can benefit enormously from the design and implementation of novel chelating nanomaterials. Available commercial resins capable of sequestering metals are based on bulk materials such as organic polymers, ceramics, and their composites. The use of two-dimensional nanoplatforms with large surface areas expands the horizon for the research and development of new systems with higher efficiency and lower cost. Fundamental science challenges remain in the synthesis and characterization of these nanomaterials and their integration with known or novel coordinating ligands.

Chemical exfoliation of graphite under strong oxidizing conditions yields graphene oxide (GO) …

Design Of Collagen-Mimetic Peptides, Parminder Jeet Kaur

Dissertations, Theses, and Capstone Projects

Collagen is the major component of the extracellular matrix and is involved in a wide range of cellular functions during tissue development and action. At the core of the diverse functions of this versatile protein is its remarkable ability to form supramolecular structures through self-assembly and/or through interactions with other biomolecules. One typical example of such supramolecular structure is the fibrils of collagen types I, II and III of the connective tissues. These fibrils have staggered arrangement of the laterally associated collagen triple helices – the structural unit of collagen – to form long, smooth fibrils with a characteristic 67 …

Synthesis Of Complex/Multifunctional Metal (Hydr)Oxide/Graphite Oxide/Aunps Or Agnps Adsorbents And Analysis Of Their Interactions With Chemical Warfare Agents, Dimitrios A. Giannakoudakis

Dissertations, Theses, and Capstone Projects

One of the most widely used chemical warfare agent (CWA) is mustard gas, which is a highly toxic blistering agent. In this study we investigated the interactions of mustard gas surrogates’ vapors on zinc and zirconium hydroxides and their composites with graphite oxide (GO) and/or Au or Ag nanoparticles. Even though a small quantity of reports about the detoxification of CWAs on metal oxides is reported in the literature, almost all of these studies are performed in the liquid phase. Both herein reported Zn(OH)₂ and Zr(OH)₄ showed a good adsorption performance, with the former being photoactive under visible …

Development Of New Radiolabeling Methods And Insights On Ionizing Radiation Interactions With Nanoparticles, Travis Shaffer

Dissertations, Theses, and Capstone Projects

Nanoparticles are often combined with radionuclides for various applications, ranging from waste remediation to imaging and therapy in the medical field. The overarching aim of this body of work is two-fold. The first aim is development of new radiolabeling methods for various nanoparticles that allow stable attachment of a variety of imaging and therapeutic radionuclides. The second portion more fully describes mechanisms of interaction between ionizing radiation and nanoparticles.

The following advancements will be presented in this dissertation: i) a new radiolabeling method for silica and silica-based nanoparticles that does not require the use of specific chelators, with both radiochemical …

Sustainable Molecular Gelators: Beta-D-Glucoside Derived Structuring Agents And Their Material Application, Julian R. Silverman

Dissertations, Theses, and Capstone Projects

Though molecular gelators may by synthesized and formulated into gels following a variety of methods, it should serve that the most valued methods may utilize renewable and waste resources and follow sustainable procedures. Molecular gelators are systems capable of structuring liquids into solid-like materials and they represent a class of surfactant and amphiphilic materials which posses the capability to be not only useful in their ability to form gels, but multifunctional in the ability to respond smartly to a variety of stimuli. Thus there is an interest in the development of sustainable molecular gelators capable of being applied to applications, …

Photodynamic Killing Of Human Cancer Cells With Smart Photosensitizer Materials And An Endoscopic Implement For Singlet Oxygen Delivery, Mihaela N. Minnis

Dissertations, Theses, and Capstone Projects

The thesis describes progress on probe tips for a microoptic device for the precise delivery of the components necessary for photodynamic therapy (PDT) in a highly localized and controllable fashion. The thesis also summarizes results of a photosensitized oxidation study. The work focused on i) developing a photoactive fluoropolymer surface that will release sensitizer drug molecule for use in PDT, ii) designing new probe tips surfaces for use as sensitizer support for a microoptic PDT device, iii) exploring strategies for covalent attachment of sensitizers and model compounds to Teflon/PVA surfaces with the aim of being coupled with our microoptic device, …

Probing The Structure And Photophysics Of Porphyrinoid Systems For Functional Materials, Christopher D. Farley

Dissertations, Theses, and Capstone Projects

Porphyrins (Pors) and their many cousins, including phthalocyanines (Pcs), corroles (Cors), subphthalocyanines (SubPcs), porphyrazines (Pzs), and naphthalocyanines (NPcs), play amazingly diverse roles in biological and non-biological systems because of their unique and tunable physical and chemical properties. These compounds, collectively known as porphyrinoids, can be employed in any number of functional devices that have the potential to address the challenges of modern society. Their incorporation into such devices, however, depends on many structural factors that must be well understood and carefully controlled in order to achieve the desired behavior. Self-assembly and self-organization are key processes for developing these new technologies, …

Design Rules For The Nucleation, Growth, And Encapsulation Of Gold Nanoparticles With Applications To Cancer Imaging, Matthew A. Wall

Dissertations, Theses, and Capstone Projects

Surface-enhanced Raman scattering (SERS) nanoparticles are exciting candidates for high-precision cancer imaging due to their highly specific spectral signature (Raman “fingerprint”) and propensity for passive targeting of cancerous tissues. However, the signal intensity of currently available SERS nanoparticles is insufficient for cancer imaging via passive targeting in most solid tumors. The overarching aim of this body of work is to develop a new generation of SERS nanoparticles with sufficiently low limits of detection to enable robust detection of various solid tumors in vivo.

The complexity of SERS nanoparticles requires significant advances to the theoretical and experimental understanding of metal …

Ultrafast Spectroscopy And Energy Transfer In An Organic/Inorganic Composite Of Zinc Oxide And Graphite Oxide, Jeff A. Secor

Dissertations, Theses, and Capstone Projects

The energy transfers and nature of defect levels of an organic/inorganic composite of Zinc Oxide and Graphite are studied with multidimensional spectroscopy. The edge and surface states of each composite are uncovered using excitation emission experiments showing which defect states are mediating the energy transfer from the metal oxide to the graphite oxide. Multidimensional time resolved spectroscopy further describes the effect of the carbon phase on the energy transfer pathways in the material.