Chemistry Commons^™

Designing Dual-Responsive Drug Delivery Systems: The Role Of Phase Change Materials And Metal-Organic Frameworks., Wanying Wei, Ping Lu

College of Science & Mathematics Departmental Research

Stimuli-responsive drug delivery systems (DDSs) offer precise control over drug release, enhancing therapeutic efficacy and minimizing side effects. This review focuses on DDSs that leverage the unique capabilities of phase change materials (PCMs) and metal-organic frameworks (MOFs) to achieve controlled drug release in response to pH and temperature changes. Specifically, this review highlights the use of a combination of lauric and stearic acids as PCMs that melt slightly above body temperature, providing a thermally responsive mechanism for drug release. Additionally, this review delves into the properties of zeolitic imidazolate framework-8 (ZIF-8), a stable MOF under physiological conditions that decomposes in …

Analysis On Development Trend Of Global Hypersonic Technology, Xiaorong Huang, Yunwei Chen, Haichen Zhou

Bulletin of Chinese Academy of Sciences (Chinese Version)

Hypersonic technology is a key technology in the aerospace field in the future and is of very important strategic and forward-looking significance. Using bibliometric methods, it is found that research on hypersonic technology is mainly concentrated in the military field, among which power propulsion technology, navigation guidance and control technology, thermal protection technology and new materials are important research directions in this field. After sorting out the research and development situation of various countries, it is found that the relevant core technologies related to the development of hypersonic weapons are still the focus of future research. At the same time, …

Thermal Effects On The Voc-Sensitive Polydimethylsiloxane Holographic Gratings, Aleksandra Hernik, Faolan Radford Mcgovern, Patrick Iftime, Izabela Naydenova

Conference Papers

The imperative for monitoring volatile organic compounds (VOCs) emerges from their harmful impact on human health when inhaled excessively over a long term. Polydimethylsiloxane (PDMS), valued for its transparency and excellent flexibility, has already been demonstrated as a promising biocompatible and cost-effective transducer for optical VOCs sensing. Moreover, it facilitates further functionalisation with adsorbing materials to enhance sensitivity and selectivity for specific VOCs detection. We fabricated and examined PDMS-based surface diffraction gratings after exposure to selected VOCs, demonstrating different response for polar and non-polar molecules. Investigated gratings were prepared by replicating sinusoidal surface relief structures inscribed in acrylamide photopolymer using …

Investigation Of The Uv-Resistance Of Photopolymerisable Glass For Space Applications, Luca Sorridente, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

The progress of space based scientific research leads to an increasing demand for more efficient and less bulky instruments. Conventional refractive elements make up a critical part of many optical instruments launched into space; however, they can be bulky and heavy. Holographic optical elements are an efficient alternative to replace the conventional optical elements as they are lightweight and can be miniaturized. Current materials typically used for volume holographic optical elements are not robust enough for use in space environment. Recently a promising photopolymerisable glass has been developed using a sol-gel technique, which can provide dry layers suitable for holographic …

Photopolymer Material Durability And Safety In Holographic Diffusers For Visual Applications, Matthew Hellis, Alan Casey, Edoardo Splendi, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

This study introduces novel holographic diffuser applications employing acrylamide- or diacetone acrylamide-based photopolymers, patterned within the volume on a micron scale by a single-beam holographic recording process. These diffusers have previously been presented as potential treatments for amblyopia and diplopia. This work has now been extended to spectrometric analysis to determine their properties under broadband light. Diffusive elements with higher diffusion efficiencies exhibited a marginal reduction (< 5%) in diffusion efficiency across most of the visible spectrum. Given the intended application of these holographic diffusers, cytotoxicity assessments were also performed. This is significant as there is a difference in toxicity between the crystalline acrylamide (classified as a category 3 material) and diacetone acrylamide (classified as a category 4 material). The findings indicated substantially lower toxicity in holograms produced with diacetone acrylamide-based photopolymer. The accelerated ageing of both formulations of holographic diffusers indicated that the acrylamide-based holographic diffusers did not reduce efficacy in the 292 days of ageing. The diacetone acrylamide-based holographic diffusers exhibited reduced efficacy by day 182. Despite this, both formulations have been shown to perform for prolonged periods as the treatment modality would require. These results emphasise that holographic diffusers exhibit minimal spectral impact, and longevity on the scale of treatment regimes which are crucial considerations for their prospective use case as treatments for amblyopia and diplopia.

Activity Descriptors As Tools For Designing Highly Efficient Electrocatalysts For Water Splitting, Aya Gomaa

Theses and Dissertations

There is an uprising urge to design efficient, active, and durable catalysts to achieve sustainable hydrogen production. The unambiguity of which material should be used pushed the scientific community to devote enormous efforts in exploring different elements with different ratios on trial and error bases. However, the bridge between the theoretical calculation and the experiments introduced a new realm of designing efficient catalysts by introducing the concept of activity descriptors. In the first part of the thesis, the ability to convert waste stainless steel (SS) 316L meshes into highly efficient and durable oxygen evolution reaction (OER) catalysts is demonstrated. The …

Zinc Oxide Nanostructures Synthesized By Hot Water Treatment For The Photocatalytic Degradation Of Organic Pollutants In Water, Ranjitha Kumarapuram Hariharalakshmanan

Theses and Dissertations

Photocatalysis using nanostructured semiconductors for the degradation of organic pollutants has received significant attention as an advanced water treatment method. A photocatalyst absorbs light with energy greater than or equal to its band gap and generates electron-hole pairs. These electrons and holes take part in redox reactions in water to generate reactive oxygen species, such as hydroxyl radicals and superoxide anions, which can break down organic contaminants. However, this method has some challenges, such as electron-hole recombination, which reduces the efficiency, high cost of nanostructure synthesis, and reduced durability of nanostructured photocatalysts in suspension form. The immobilization of photocatalyst nanostructures …

Molecular-To-Continuum Scale Modeling Of Aerosols: Atmospheric Application And Beyond, Ella Ivanova

Dissertations

Aerosol modeling is critical for various applications, such as climate forecasting, air quality, and human health impact assessment. During their lifetime, aerosols undergo a complex evolution, usually divided into several stages — formation, processing, transport, and removal — that occur on different scales. Thus, the choice of modeling methods depends on the stage considered. For example, certain stages of particle formation may require nano-scale modeling while aerosol-cloud interactions span from microscale to mesoscale. This study examines the modeling of aerosol behavior over a wide range of scales, from nano to microscale, with implications to mesoscale.

This dissertation focuses on two …

Holographic Multiplexing In A Photopolymerisable Hybrid Sol-Gel, Pamela Stoeva, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

Holographic multiplexing techniques enhance functionality and information storage by leveraging the inherent selectivity of holograms. This is crucial for advancing holographic sensors, which excel in simultaneously detecting multiple parameters from a single input signal. This study explores the potential of the recent photopolymerisable hybrid sol-gel (PHSG) material for application in Space sensing systems through the investigation of its holographic angular multiplexing capabilities. For the first time, to the best of our knowledge, we report the successful recording of up to five angularly multiplexed gratings with diffraction efficiencies (DE) ≥ 15% in 187 ± 18 µm PHSG layers. A 3 mW/cm2 …

Comparison Of Ligands In Palladium-Catalyzed Electrochemical Allyl 4-Pyridinylation, Wei-Jie Ding, Chun-Hui Yang, Zhong-Tao Feng, Shi-Rong Lu, Xu Cheng

Journal of Electrochemistry

4-CN-pyridine is a widely applied 4-pyridinylation reagent for diverse transformations. Conventionally, the reaction proceeds via an open-shell radical cross-coupling pathway. Following our previous study, in this work, we report the Pd-catalyzed allyl 4-pyrinylation reaction under electrochemical conditions. The reaction proceeds via radical-polar crossover pathway in which the role of phosphine ligand in reactivity and selectivity was extensively investigated.

Nickel-Catalyzed Α-Arylation Of Α-Cyanoacetates Enabled By Electrochemistry, Zi-Meng Li, Zhang-Jian Li, Anat Milo, Ping Fang, Tian-Sheng Mei

Journal of Electrochemistry

β-Amino acids have a wide range of applications in the field of pharmaceuticals. Utilizing a combination strategy of nickel catalysis and paired electrolysis, a catalytic α-arylation protocol of carbonyl compounds has been developed. This protocol affords various a-aryl-a-cyanoacetates, which can be reduced to high-value-added α-aryl-β-amino acids. The cross-coupling reaction of electron-deficient aryl bromides with a-cyanoacetates achieves the expected products with good yields and functional group compatibility under mild conditions. Excessive electron-richness in initial aryl bromides facilitates the self-coupling of desired products. DFT calculations confirm that the presence of electron-rich aryl substitutions decreases the reduction potentials of the product anions, making …

Recent Advance In Electrochemical Dehalogenative Deuteration, Peng-Fei Li, Guang-Sheng Kou, Li-Ping Qi, You-Ai Qiu

Journal of Electrochemistry

In recent years, the incorporation of deuterium atoms into organic compounds has emerged as a vital focus in the development of pharmaceutical molecules. This trend is driven by the increasing recognition of the significance of compounds containing deuterium atoms across various domains, including materials and biopharmaceuticals, where they have found widespread applications in mechanistic studies within the realms of chemistry and biology. Meanwhile, organic electrochemistry, as a relatively environmentally friendly catalytic mode with broad adaptability to redox reactions, has emerged as a crucial alternative to traditional halogen-deuterium exchange in the context of the reduction deuteration of halides. This approach circumvents …

Non-Destructive Determination Of Surface Area In Reverse Phase Chromatographic Columns, Margaret Figus

Seton Hall University Dissertations and Theses (ETDs)

Excess adsorption isotherms of acetonitrile and methanol from water were measured on eight commercial columns. Columns used in this study represent the latest examples in column development and include three different poroshell columns (Kinotex C18, Ascentis C18, and Halo C18) as well as conventional columns with significantly different adsorbent geometries (Allure C18, YMC C18) and various hybrid-silica columns (Gemini C18, Xterra C18, and XBridge C18). Comparison of the excess adsorption isotherms measured on all these columns and expressed in surface-specific form demonstrated significant similarity of the adsorption properties of all columns, which allows the introduction of the Standard Excess Adsorption …

Effects Of Ti Addition On The Characteristics Of Al-10zn-6mg-2si/Zro2 Composites Produced By Squeeze Casting, Qesha Diva Prameshvara, Pipin Indah Lestari, Bondan Tiara Sofyan

Journal of Materials Exploration and Findings

Metal matrix composite (MMC) with 7xxx aluminum matrix is potential for ballistic applications due to the combination of strength, toughness, and light weight. Previous study successfully produced aluminum-based composites with SiC particles which were able to stop type III bullet, however cracks remained on back of the plate. Therefore, in this research, SiC was replaced by zirconia (ZrO₂) due to its high fracture toughness. Ti-B grain refiner was added to further improve toughness through grain boundary strengthening mechanism. This research developed 5 vol.% ZrO₂ strengthened Al-10Zn-6Mg-2Si composite with addition of Al-5Ti-1B grain refiner produced through squeeze casting …

Analysis Of The Effect Of Different Surface Preparation Methods On Corrosion Resistance And Adhesion Strength Of Astm A36 Steel Substrate With Surface Tolerant Epoxy Paint As Coating Material, Irwan Wijaya Santoso, Daffa Aqila, Rini Riastuti, Rizal Tresna Ramadhani

Journal of Materials Exploration and Findings

In the industrial world, to extend the service life of materials, protection methods are carried out to slow down the material's corrosion rate. The protection method that is often used is the coating method. The coating method is a protection method by coating the substrate material using a coating material to prevent contact between the substrate material and the environment. In this research, the substrate material used is ASTM A36 steel and the coating material used is Surface Tolerant Epoxy paint. The independent variable used in this study lies in the surface preparation method which consists of: solvent cleaning, hand …

Excellent Bifunctional Oxygen Evolution And Reduction Electrocatalysts (5a1/5)Co2o4 And Their Tunability, Xin Wang, Harish Singh, Manashi Nath, Kurt Lagemann, Katharine Page

Chemistry Faculty Research & Creative Works

Hastening the Progress of Rechargeable Metal-Air Batteries and Hydrogen Fuel Cells Necessitates the Advancement of Economically Feasible, Earth-Abundant, Inexpensive, and Efficient Electrocatalysts Facilitating Both the Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR). Herein, a Recently Reported Family of Nano (5A1/5) Co2O4 (A = Combinations of Transition Metals, Mg, Mn, Fe, Ni, Cu, and Zn) Compositionally Complex Oxides (CCOs) [Wang Et Al., Chemistry of Materials, 2023, 35 (17), 7283-7291.] Are Studied as Bifunctional OER and ORR Electrocatalysts. among the Different Low-Temperature Soft-Templating Samples, Those Subjected to 600 °C Post annealing Heat Treatment Exhibit Superior Performance in Alkaline Media. One …

Probing The Surface Structure Of Ferrocene Modified Electrodes Using Cyclic Voltammetry, Rebekah S. Stanley

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

Modifying electrodes imparts new electrochemical properties for use in various applications. To fully understand these electrochemical properties the structure of the modified surface needs to be characterized. Cyclic voltammetry (CV) offers a quick and simple way to determine if the surface structure has been homogeneously modified even at low surface concentrations. Nonideal responses in CV scans give insights to the microenvironments and structure of the monolayer surface that may be indistinguishable in other techniques. Peak fitting CV data, coupled with other surface techniques, can further characterize the contributions and nature of these microenvironments and aid in structural determination.

Melting Point Predictions Of Thermally Stable Ionic Liquids Using A Machine Learning Approach, Jarod Morris

Poster Presentations

Thermally robust ionic liquids hold promise as high-temperature solvents, heat transfer fluids, and high-performance lubricants. These ionic liquids, inspired by thermoplastics like PEEK and PES, incorporate peraryl functional groups that lend them high thermal stability, however they often have melting points greater than 100 °C. A broad liquid range is usually desirable in most applications, so finding thermally robust ILs with lower melting points would significantly enhance their applicability. In this study, machine learning models are developed to make predictions of melting points for these thermally stable ionic liquids using a process called quantitative structure-property relationships (QSPR). The methodology used …

The Effects Of Free Volume And Processing On The Development Of Gas Separation Membranes, Jacob Schekman

Dissertations

Structure, thermal, mechanical, gas transport, and free volume properties of thiol-ene based systems are investigated and discussed. In the pursuit of generating low energy-cost polymer membranes for gas separation, it became apparent that UV-curing of thiol-ene materials presented several routes toward achieving this goal. Network structure plays a vital role in determining the gas transport properties of membrane materials. UV photopolymerization techniques provide a means to rapidly vitrify network morphologies which can be tuned depending on choice of monomer. Thiol-ene monomers offer a broad range of precursor materials from which to choose for the design of functional membrane materials.

Chapter …

The Synthesis And Characterization Of 9,10-Bis-(Iodoethynyl)Anthracene For 2d Molecular Crystals From Halogen-Bonding, Nehemiah Antoine

Honors Theses

Two-dimensional crystals have unique properties, giving them the potential to develop practical items such as electronics, biomedicine, and sensors. Our goal is to use chemical principles to synthesize molecules that spontaneously form 2D crystals with designed patterns and properties. For this, we will exploit directional, non-covalent interactions to determine what pattern will form in 2D. In this project halogen-bonding will be utilized: halogen-bonding is the interaction between the electrophilic region of a halogen and a nucleophilic region of a Lewis base. We are functionalizing anthracenes with iodine and nitrogen to form halogen bonds that enable the molecules to pack more …

Magnetic Properties Of Zgnrs With Nitrogen And Fluorine Adsorbates, A Computational Study, Justin Petit

Electronic Theses and Dissertations

Imposing dimensional restrictions on graphene sheets and adding impurities can give rise to carbon nanostructures with magnetic properties. In this work, zigzag graphene nanoribbons, zGNRs, with nitrogen and fluorine adatoms are investigated for magnetic properties of interest for spin devices. Geometry optimizations were done determining which position along a zGNR electrode that N and F would favorably attach to. Edge positions were determined as the most stable attachment site. M-cell zGNR electrodes (M = 1-3) edge-functionalized by N and F adatoms were investigated with respect to their band structures and spin densities in antiferromagnetic and ferromagnetic, AFM and FM, configurations. …

Conversion Of Microcrystalline Cellulose To Hexane Using Hydrogenated Metal Oxides At Low Temperature And Pressure, Mubarak Osman

Electronic Theses and Dissertations

Increasing global energy demand and environmental concerns have fueled the exploration of sustainable and efficient methods for renewable fuel production. The conversion of cellulosic waste to hydrocarbon fuels using hydrogenated metal oxides presents a novel and eco-friendly approach to sustainably address energy demand. In this study, hydrogenated metal oxides were used as catalysts in a relatively low-temperature and atmospheric-pressure environment to facilitate the conversion of cellulosic waste into hydrocarbon fuels. Hydrogenated metal oxides have been introduced as potential hydrogen transfer catalysts. The expected result is the selective conversion of cellulose to hexane at relatively low temperatures, which significantly reduces energy …

Revealing The Three-Dimensional Arrangement Of Polar Topology In Nanoparticles, Chaewa Jeong, Juhyeok Lee, Hyesung Jo, Jaewhan Oh, Hionsuck Baik, Kyoung-June Go, Junwoo Son, Si-Young Choi, Sergey Prosandeev, Laurent Bellaiche, Yongsoo Yang

Physics Faculty Publications and Presentations

In the early 2000s, low dimensional ferroelectric systems were predicted to have topologically nontrivial polar structures, such as vortices or skyrmions, depending on mechanical or electrical boundary conditions. A few variants of these structures have been experimentally observed in thin film model systems, where they are engineered by balancing electrostatic charge and elastic distortion energies. However, the measurement and classification of topological textures for general ferroelectric nanostructures have remained elusive, as it requires mapping the local polarization at the atomic scale in three dimensions. Here we unveil topological polar structures in ferroelectric BaTiO₃ nanoparticles via atomic electron tomography, which …

Synthesis, Electrical Conductivity, Electrocatalytic Activity For Water Splitting, And Pseudocapacitive Properties Of Perovskite Oxide Derivatives., Kinithi Meththa Kumari Wickramaratne

Electronic Theses and Dissertations

Developing green and sustainable energy solutions is crucial to addressing the energy and environmental challenges. Hydrogen is an attractive candidate given its high energy density and low carbon emission compared to gasoline and coal. Electrochemical water splitting through a water electrolyzer is recognized as a green method for generating hydrogen and oxygen gases. Developing cost-effective electrocatalysts to reduce overpotential in hydrogen and oxygen generation is essential for the overall process. The growing interest in perovskite oxides as versatile and sustainable catalysts is driven by their compositional flexibility, tunable electronic structure, earth abundance, and inherent catalytic performance. In our research, we …

Structure-Property Relationship Studies Of Electrically Conductive Metal-Organic Framework Materials, Shiyu Zhang

All Dissertations

Electrically conductive metal-organic frameworks (EC-MOFs) are among the most promising materials due to their tunable structures, properties, and diverse functions. However, the lack of comprehensive understanding of their structure-property relationship hinders the development of EC-MOFs. My dissertation focuses on the design, construction, and structure-property relationship studies of EC-MOFs.

Chapter 1 describes how MOFs' structural features and compositions affect the electronic properties and demonstrates conductive mechanisms and the corresponding design strategies to develop EC-MOFs.

Chapter 2 describes the synthesis, characterization, electronic and optical properties of four novel alkali-metal-based (Na, K, Rb, and Cs) 3D-MOFs with continuous tetrathiafulvalene tetracarboxylate (TTFTC) π-stacks, systematicly …

Carbon "Quantum" Dots: Structures, Properties, And Issues, Weixiong Liang

All Dissertations

Carbon dots (CDots) are small carbon nanoparticles (CNPs) with effective surface passivation. The effective passivation has been achieved by the surface functionalization of pre-existing CNPs with organic molecules, mostly molecules containing primary or secondary amine moieties. In the studies highlighted in this dissertation, CNPs were functionalized by selected organic molecules, including especially the use of radical addition reactions, to generate CDots with strong absorption and bright fluorescence emissions. A good demonstration of the approach was the N-ethylcarbazole (NEC) radical addition to CNPs under microwave irradiation. Spectroscopy and microscopy methods were employed to characterize the resulting NEC-CDots, and the results …

Bridging The Gap Between Molecular Components And Functional Electronic Chemical Sensing Devices With 2d Layered, Conductive Metal–Organic Frameworks, Emma Katherine Ambrogi

Dartmouth College Ph.D Dissertations

Layered, conductive framework materials are a class of materials with properties that make them ideal sensing materials in electronic chemical sensors. My thesis is focused on the development of these materials for electrochemical sensing of liquid phase analytes, and on understanding the material–analyte and material–electrode interfaces, and their self-assembly and deposition onto surfaces.

Chapter 1 provides a summary of the use of layered conductive metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) in electronic chemical sensors, detailing the materials and sensor architectures employed, and the analytes detected. Relevant performance metrics are compared, and investigations into material–analyte interactions are highlighted.

Chapter …

Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu

Journal of Electrochemistry

Zero-emission of desulfurization wastewater is one of the main demands for coal-fired power plants. As typical high salinity wastewater, it is hard to purify the desulfurization wastewater from coal-fired power plants through traditional physicochemical treatment or biochemical treatment, e.g., COD and Cl^–. A high concentration of Cl^– ion in desulfurization wastewater restricts wastewater reuse and zero-emission. Electrochemical technology is an attractive method for high salinity wastewater zero-emission, which provides a versatile, efficient, cost-effective, easily automatable, and clean industrial process. For advanced treatment of effluent after triple box process treatment in power plants, this paper reports an electrochemical …

Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu

Journal of Electrochemistry

The development of novel strategies to access cyclopropanes has become increasingly important due to the vital role of these three-membered ring structures in synthetic intermediates, natural products, and pharmaceuticals. Herein, we present an electrocatalytic method for the synthesis of cyclopropanes through intermolecular dehydrogenative annulation of active methylene compounds and arylalkenes. This electrochemical process requires no chemical oxidants, allowing for a speedy access to various functionalized cyclopropanes from inexpensive and readily available materials.

Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng

Journal of Electrochemistry

Aryl-substituted benzothiophene and phenanthrene are important structural units in medicinal chemistry and materials science. Although extensive effort has been devoted to prepare these compounds and a variety of approaches have been developed to construct the 2-substituted benzothiophene core structure, environmental-friendly and efficient synthetic means are still desired. Based on our previous electrochemical Minisci-type arylation reaction with aryl diazonium salt as the aryl precursor, as well as the work from König’s group, herein, we described the use of paired electrolysis to achieve 2-aryl benzothiophenes and 9-aryl phenanthrenes employing benzenediazonium salts as the aryl radical precursors. Initially, 2-methylthiobenzendiazonium salt 1a and 4-methylbenzene …