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Full-Text Articles in Physical Sciences and Mathematics

Investigating The Electrochemical Behavior Of Dihydropyrrolopyroles For Use As Anodically Coloring Electrochromes, Perry Skiouris, Ally Kisiel, Valentino Sorto, Julia Mauro, Graham Collier Dec 2022

Investigating The Electrochemical Behavior Of Dihydropyrrolopyroles For Use As Anodically Coloring Electrochromes, Perry Skiouris, Ally Kisiel, Valentino Sorto, Julia Mauro, Graham Collier

Symposium of Student Scholars

Electrochromic materials have found widespread use in consumer electronics, energy saving windows, and military applications. They contain unique electronic properties allowing them to undergo a color change in a redox reaction. One classification of these molecules is known as anodically coloring electrochromes (ACEs). When in solution, these compounds are transmissive in the neutral (ground) state and absorb visible light upon oxidation, by the formation of a radical cation, thus making them colored. The focus of this study is the electronic transitions of this radical cation and how chemical modifications to the structures produce a variable color profile. To design prospective …


Synthesis And Characterization Of A Novel Reaction-Based Azaborine Fluorescent Probe Capable Of Selectively Detect Carbon Monoxide Based On Palladium-Mediated Carbonylation Chemistry, Samuel Moore, Carl Jacky Saint-Louis Apr 2022

Synthesis And Characterization Of A Novel Reaction-Based Azaborine Fluorescent Probe Capable Of Selectively Detect Carbon Monoxide Based On Palladium-Mediated Carbonylation Chemistry, Samuel Moore, Carl Jacky Saint-Louis

Symposium of Student Scholars

Azaborines are fascinating compounds because they possess valuable properties such as photochemical stability, have high molar absorption coefficient and high fluorescent quantum yields, as well as large Stokes shifts and tunable absorption/emission spectra. Here, we designed, synthesized, and will examine a novel reaction-based azaborine fluorescent probe capable of selectively detect carbon monoxide (CO) based on palladium-mediated carbonylation chemistry. This novel azaborine fluorescent probe will exhibit high selectivity for CO and display a robust turn-on fluorescent response in the presence of CO in aqueous buffer solution.


Ketal-Azaborine Versus Ketal-Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Heteroaromatic Polycyclic Chromophores, Albert Campbell, Janiyah Riley, Samuel Moore, Albert Campbell Apr 2022

Ketal-Azaborine Versus Ketal-Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Heteroaromatic Polycyclic Chromophores, Albert Campbell, Janiyah Riley, Samuel Moore, Albert Campbell

Symposium of Student Scholars

Flat-structured heteroaromatic polycyclic compounds with extended conjugated π-systems such as azaborines are in high demand in the material and imaging technology markets because of their unique features such as simultaneous tunability of fluorescence color and intensity. We have designed, synthesized, and investigated a series of novel conjugated thermally stable ketal-azaborine chromophores that contain a phenyl ring as a spacer between electronic moieties and the ketal-azaborine core as easily tunable high-luminescent organic materials. We investigated the impact of the phenyl spacer on the ketal-azaborine unit. We examined the structural effects on their photophysical properties by incorporating electron –donating and –withdrawing substituents …


Azaborine Versus Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Azaborine Chromophores, Kaia Ellis, Janiyah Riley, Lyric Gordon, Janiyah Riley Apr 2022

Azaborine Versus Azaborine With A Spacer: Structural Effects On The Photophysical Properties Of Tunable Azaborine Chromophores, Kaia Ellis, Janiyah Riley, Lyric Gordon, Janiyah Riley

Symposium of Student Scholars

Azaborines are fascinating compounds because of their valuable and interesting optical properties making them suitable to be utilized in many optoelectronic devices. We have designed, synthesized, and investigated a series of novel conjugated thermally stable azaborine chromophores by incorporating a phenyl ring as a spacer linking the chromophore to different electronic moieties as easily tunable high-luminescent organic materials. We investigated the effect of the phenyl spacer on the azaborine unit. The substituent effects of different electronic moieties were investigated by the insertion of electron –withdrawing and –donating moieties to the phenyl spacer. We examined the role of the electron –donating …


High Speed Impact On Graphene Composites, Giovanny A. Espitia Aug 2021

High Speed Impact On Graphene Composites, Giovanny A. Espitia

Symposium of Student Scholars

Since the isolation of Graphene occurred in 2004, numerous studies attempting to exploit the properties of this carbon allotrope have been conducted. Graphene exists in a 2-D manner with sp2 bonds, which provides the allotrope with great electrical, conductive, and mechanical properties. In this paper however, we will focus on the latter in order to examine the feasibility of graphene composites for bulletproof material in the military. Pure graphene sheets count with high porosity density that leads to structural defects as well as poor mechanical properties due to physical contact being sole retainer. For this reason, the selected composite is …


Activated Carbon Pore Expansion Using Acidic Hydrothermal Method, Max Thompson Aug 2021

Activated Carbon Pore Expansion Using Acidic Hydrothermal Method, Max Thompson

Symposium of Student Scholars

Petroleum Coke is a widely abundant, high carbon content material produced as a byproduct of the oil refining process. Its abundance makes the price per ton low and it is produced in almost all regions of the world. Due to the low price and high carbon percentage, commercial companies make large amounts of activated carbon using petroleum coke as a precursor. These activated carbons are characterized by their high surface area and can achieve widely varying pore morphology with different activation processes. The goal of this work is to achieve a homologous mesopore activated carbon material for use in super …


Solid-State Redox Synthesis Of Layered Birnessite-Type Manganese Dioxide (Δ-Mno2) As Aqueous Supercapacitor Electrodes, Armando Rodriguez Campos Aug 2021

Solid-State Redox Synthesis Of Layered Birnessite-Type Manganese Dioxide (Δ-Mno2) As Aqueous Supercapacitor Electrodes, Armando Rodriguez Campos

Symposium of Student Scholars

Nanostructured manganese dioxides are attractive cathode materials in aqueous supercapacitors due to their low cost, environmental benign nature, high theoretical gravimetric capacitance, and power in neutral aqueous electrolytes. In this work, a layered birnessite-type manganese dioxide (δ-MnO2) is synthesized utilizing solid-state redox method with superoxide. The effects of temperature and oxidant amount on the physicochemical properties of δ-MnO2 are characterized using Elemental Dispersion X-ray (EDX) spectroscopy, X-ray diffraction (XRD), N2-sorption, and Scanning Electron Microscope (SEM). The physiochemical properties that are specifically analyzed by varying synthesis conditions pertain to the chemical composition, morphology, and surface area …


Design Of 3d Macroporous Inverse Opal Tio2 Binary And Ternary Composites Sensitized With Gold Nanoparticles And Cds Quantum Dots For Photocatalysis, Daniel A. Corella Apr 2017

Design Of 3d Macroporous Inverse Opal Tio2 Binary And Ternary Composites Sensitized With Gold Nanoparticles And Cds Quantum Dots For Photocatalysis, Daniel A. Corella

Master of Science in Chemical Sciences Theses

Materials composed of titanium (IV) oxide (TiO2) have received enormous scientific interest due to titania’s abundance, non-toxicity, and photocatalytic proficiency, however its large band gap limits its applicability under ambient conditions. Various attempts have been made to incorporate titania into composite systems to sensitize it for activity under a broader range of wavelengths. One such method includes utilizing narrow band gap semiconductors to form an electron transfer process analogous to photosynthesis referred to as a Z-scheme. Z-scheme systems can catalyze the decomposition of aqueous pollutants via generation of reactive oxygen species after input of sunlight. This work reports …


Cacao Use And The San Lorenzo Olmec, Terry G. Powis, Ann Cyphers, Nilesh W. Gaikwad, Louis Grivetti, Kong Cheong May 2011

Cacao Use And The San Lorenzo Olmec, Terry G. Powis, Ann Cyphers, Nilesh W. Gaikwad, Louis Grivetti, Kong Cheong

Faculty and Research Publications

Mesoamerican peoples had a long history of cacao use—spanning more than 34 centuries—as confirmed by previous identification of cacao residues on archaeological pottery from Paso de la Amada on the Pacific Coast and the Olmec site of El Manatí on the Gulf Coast. Until now, comparable evidence from San Lorenzo, the premier Olmec capital, was lacking. The present study of theobromine residues confirms the continuous presence and use of cacao products at San Lorenzo between 1800 and 1000 BCE, and documents assorted vessels forms used in its preparation and consumption. One elite context reveals cacao use as part of a …