Materials Chemistry Commons^™

Composite And Polymer Formulation Employing Sulfur And Bio-Olefin Feedstocks, Claudia V. Lopez

All Dissertations

Environmental sustainability represents a challenge for society since industrial growth has a direct impact on natural resources and waste production. New technologies that effectively incorporate waste into renewable resources are critical to the development of a sustainable and circular economy. The manufacturing of structural materials like Portland cement (OPC) is responsible for >8% of the global anthropogenic emissions of carbon dioxide, with ~ 1 kg of CO₂ released to the atmosphere for every kilogram of OPC produced. For instance, the development of sustainable structural materials is a key factor to reduce the greenhouse emissions and to attenuate the climate …

Leveraging Non-Covalent Interactions Between Small Organic Molecules And Inorganic Scaffolds In The Design Of Advanced Materials, Jonathan Lefton

Chemistry Theses and Dissertations

Powder diffraction is a powerful tool for studying crystal structures, especially as it relates to interactions of small organic molecules with inorganic compounds. The first part of this dissertation involves small organic ligands interacting with metal-organic framework, MOF-74. The first and simplest iteration involves the crystal structure solution of a neat, liquid loading of n-propylmercaptan to the open metal sites within the MOF-74 pores. Later studies investigate the leveraging of a similarly sized bitopic ligand in the solution loading of 1,2-ethanedithiol, which results in the amorphization of MOF-74. Having no crystallinity, amorphous or severely defected materials can be a …

Recent Progress Of Bifunctional Electrocatalysts For Oxygen Electrodes In Unitized Regenerative Fuel Cells, Tian-Long Zheng, Ming-Yu Ou, Song Xu, Xin-Biao Mao, Shi-Yi Wang, Qing-Gang He

Journal of Electrochemistry

Unitized regenerative fuel cells (URFCs), which oxidize hydrogen to water to generate electrical power under thefuel cells (FCs) mode and electrolyze water to hydrogen under the water electrolysis (WE) mode for recycling, areknown as clean and sustainable energy conversion devices. In contrast to the hydrogen oxidation reaction (HOR) andhydrogen evolution reaction (HER) on the hydrogen electrode side, the sluggish kinetics of oxygen reduction reaction(ORR) and oxygen evolution reaction (OER) on the oxygen electrode side requires highly efficient bifunctional oxygencatalysts. Conventional precious metal oxygen catalysts combine Pt and IrO₂ with excellent ORR and OER activities toachieve bifunctional electrocatalysis performance, but …

Ultramicroelectrode Experiments: Principles, Fabrications And Voltmmetric Behaviors, Zhen Ma, Jia-Yang Lin, Wen-Jing Nan, Lian-Huan Han, Dong-Ping Zhan

Journal of Electrochemistry

Due to the small size at least in one dimension (< 25 μm), ultramicroelectrode (UME) has small electric-double-layer capacitance, low IR drop, rapid mass transfer rate, fast response, high signal/noise ratio and high spatiotenporal resolution. UME is qualified not only to study the kinetics of fast electrode processes, but also to act as the probe of scanning electrochemical microscopies to obtain the localized chemical or electrochemical reactivity of the substrates. Thus, UMEs play a significant role in various research domains of electrochemistry, and have become an important electrochemical experimental method. Herein, we will introduce the basic principles, a simple fabrication method and voltammetric experimental protocols of UME, providing a guide to carry out the UME experiments.

Band Alignments Of Metal/Oxides-Water Interfaces Using Ab Initio Molecular Dynamics, Yong-Bin Zhuang, Jun Cheng

Journal of Electrochemistry

Band alignments of electrode-water interfaces are of crucial importance for understanding electrochemical interfaces. In the scenario of electrocatalysis, applied potentials are equivalent to the Fermi levels of metals in the electrochemical cells; in the scenario of photo(electro)catalysis, semiconducting oxides under illumination have chemical reactivities toward redox reactions if the redox potentials of the reactions straddle the conduction band minimums (CBMs) or valence band maximums (VBMs) of the oxides. Computational band alignments allow us to obtain the Fermi level of metals, as well as the CBM and VBM of semiconducting oxides with respect to reference electrodes. In this tutorial, we describe …

Electrochemical Scanning Tunneling Microscopy: Taking The Initial Stage Of Cu Electrodeposition On Au(111) As An Example, Zhuo Tan, Kai-Xuan Li, Bing-Wei Mao, Jia-Wei Yan

Journal of Electrochemistry

Electrochemical scanning tunneling microscopy (ECSTM) plays an important role in the field of electrochemistry, which can obtain potential-dependent structural information of electrode surface with high spatial resolution and observe some reaction processes in electrolyte solutions, and provide a powerful way to understand the interfacial structure and electrode processes from the perspective of high spatial resolution. In this article, the study of electrodeposition of Cu on Au (111) by ECSTM is taken as an example to introduce the experimental methods required for ECSTM and share our experience with other electrochemical groups. Firstly, the working principle of STM is introduced so that …

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

The Effect Of Heat Treatment And Chemical Treatment On Natural Fibre To The Durability Of Wood Plastic Composites – A Review, Nuratiqah Asyiqin Mohd Nasharudin, Nur Fatihah Sulaiman, Nurul Aziemah Mohammad, Wan Nor Raihan Wan Jaafar, Falah Abu Dr., Siti Norasmah Surip

Journal of Materials Exploration and Findings

The application of WPC is not only limited to indoor applications but has been extended to exterior applications where properties of WPC could compromise during service life. WPC was derived from wood fiber of various sizes to reinforce polymers. Wood fiber has the advantage of a cheaper price, being abundantly available, and ease of processing, however, the critical factor is its hydrophilic nature, where moisture absorption is likely to occur. Thus, treatments for reducing the hydrophilicity of wood fibers are applied. By treatment of wood fiber, the surface impurities were removed, leaving the roughened surface of fibers, thus providing a …

Clear As Glass: Novel Antibiotic Glasses Vitrified From Solution, Claire Lamberti

Chemistry Theses and Dissertations

The World Health Organization (W.H.O.) has maintained a list of essential medicines since 1977 (1). This list contains the medications considered to be the most effective and of the utmost importance to the needs of worldwide healthcare systems. If new forms of these drugs can be created, they can be studied for potential stability and transportation purposes, as well as drug delivery mechanisms. There are strategies to try and improve the physicochemical properties including forming polymorphs, salts, cocrystals, and amorphous formulations. There are issues with these techniques, and a large one is that in most cases the crystal structures of …

Recent Advances In Electrochemical Impedance Spectroscopy-Based Pathogenic Bacteria Sensing, Tao Chen, Yuan-Hong Xu, Jing-Hong Li

Journal of Electrochemistry

Pathogenic bacteria have been throwing great threat on human health for thousands of years. Their real-time monitoring is in urgent need as it could effectively halt the spread of pathogenic bacteria and thus reducing the risk to human health. Up till now, diverse technologies such as electrochemistry, optics, piezoelectricity and calorimetry have been developed for bacteria sensing. Therein, electrochemical impedance spectroscopy (EIS)-based sensors show great potential in point-of-care bacterial analysis because of their low-cost, short read-out time, good reproducibility, and portable equipment construction. In this review, we will primarily summarize the typical applications of electrochemical impedance technology in bacteria sensing …

Metal-Organic Frameworks For Electrochemical And Electrochemiluminescent Immunoassay, Xiao-Li Qin, Zi-Ying Zhan, Sara Jahanghiri, Kenneth Chu, Cong-Yang Zhang, Zhi-Feng Ding

Journal of Electrochemistry

Development of ultrasensitive, highly accurate and selective immunosensors is significant for the early diagnosis, screening, and monitoring of diseases. Electrochemical and electrochemiluminescent (ECL) immunoassays have both attracted great attention and become a current research hotspot due to their advantages such as good stability, high sensitivity and selectivity, wide linear range, and good controllability. Metal-organic frameworks (MOFs), as a new class of porous crystalline materials, have been widely applied in electrochemical and ECL immunosensors owing to their large specific surface area, good chemical stability, as well as adjustable pore size and nanoscale framework structures. Various MOF nanomaterials with different properties for …

Preface To The Special Issue On Interfactial Regulation And Electrochemical Sensors, Jing-Hong Li, Yang Tian, Yuan-Hong Xu, Li-Min Zhang

Journal of Electrochemistry

No abstract provided.

Colorful "Stars" In The Dark, Chao Jing, Yi-Tao Long

Journal of Electrochemistry

Plasmonic nanoparticles such as Au and Ag with localized surface plasmon resonance (LSPR) property exhibit unique scattering and absorption features. The plasmonic scattering and absorption bands are mainly located at visible light region which can be easily applied in visual detections. By modulating the size, shape, and composition of gold and silver colloid solutions, plenty of colorimetric methods have been constructed for the detection of metal ions, biomolecules, and environmental contaminants, etc. For many years, the LSPR-based measurements are implemented in reagent tubes. Since 2000, the plasmon resonance scattering (PRS) light of metal nanoparticles captured by dark-field microscopy enables the …

An Aptamer-Based Microelectrode With Tunable Linear Range For Monitoring Of K+ In The Living Mouse Brain, Yuan-Dong Liu, Jia-Run Li, Li-Min Zhang, Yang Tian

Journal of Electrochemistry

Potassium ion (K⁺) is widely involved in several physiopathological processes, and its abnormal changes are closely related to the occurrence of brain diseases of cerebral ischemia. In vivo acquirement of K⁺ variation is significant to understand the roles of K⁺ playing in brain functions. A microelectrode based on single-stranded DNA aptamers was developed for highly selective detection of K⁺ in brain, in which the aptamer probes were designed to contain an aptamer part for specific recognition of K⁺, an alkynyl group used for stable confinement of aptamer probe on the gold surface, and …

Boronate Affinity-Assisted Electrochemically Controlled Atrp For Ultrasensitive Electrochemical Aptasensing Of Carcinoembryonic Antigen, Qiong Hu, Shi-Qi Li, Yi-Yi Liang, Wen-Xing Feng, Yi-Lin Luo, Xiao-Jing Cao, Li Niu

Journal of Electrochemistry

As an acidic glycoprotein, carcinoembryonic antigen (CEA) is of great value as a broad-spectrum tumor marker in the differential diagnosis and surveillance of malignant tumors. In this work, we report an electrochemical aptasensor for the ultrasensitive and highly selective detection of CEA, taking advantage of the dual amplification by the boronate affinity-assisted electrochemically controlled atom transfer radical polymerization (BA-eATRP). Specifically, the BA-eATRP-based electrochemical aptasensing of CEA involves the capture of target antigens by nucleic acid aptamers, the covalent crosslinking of ATRP initiators to CEA antigens via the selective interactions between the phenylboronic acid (PBA) group and the cis-diol group of …

Scanning Photoelectrochemical Microscopic Study In Photoinduced Electron Transfer Of Supramolecular Sensitizers-Tio2 Thin Films Systems, Sheng-Ya Zhang, Min Yao, Ze Wang, Tian-Jiao Liu, Rong-Fang Zhan, Hui-Qin Ye, Yan-Jun Feng, Xiao-Quan Lu

Journal of Electrochemistry

Crafting charge transfer channels at titanium dioxide (TiO₂) based photoanodes remain a pressing bottleneck in solar-to-chemical conversion technology. Despite the tremendous attempts, TiO₂ as the promising photoanode material still suffers from sluggish charge transport kinetics. Herein, we propose an assembly strategy that involves the axial coordination grafting metalloporphyrin-based photosensitizer molecules (MP) onto the surface-modified TiO₂ nanorods (NRs) photoanode, forming the composite MP/TiO₂ NRs photoelectrode. As expected, the resulted unique MP_B/TiO₂ NRs photoelectrode displays significantly improved photocurrent density as compared to TiO₂ NRs alone and MP_A/TiO₂ NRs photoelectrode. Scanning …

N–((2–Acetylphenyl)Carbamothioyl)Benzamide: Synthesis, Crystal Structure Analysis, And Theoretical Studies, Akin Oztaslar, Hakan Arslan

Karbala International Journal of Modern Science

N–((2–Acetylphenyl)carbamothioyl)benzamide has been synthesized and characterized. The molecular conformation of the investigated compound is stabilized by C16–H16B⋅⋅⋅O2ⁱ (i: 1+x, y, z) intermolecular and C14–H14⋅⋅⋅S1, N2–H2⋅⋅⋅O2, and N2–H2⋅⋅⋅O1 intramolecular H–bonds. All DFT calculations have been implemented at the B3LYP level with the 6–311G(d,p) basis set. The optimized molecular structure parameters have been compared with the experimental one in the solid phase. The energy gap, global chemical reactivity descriptor parameters, MEP, Fukui functions, DoS, NLO, and NBO analysis were also computed and investigated. The intermolecular interactions and their energies are evaluated using Hirshfeld surface and energy framework analyses. To determine …

Methods Of Magneto-Optical Spectroscopy And Analysis For Porphyrins And Polymer Thin-Films, Emigdio E. Turner

Chemistry and Chemical Biology ETDs

This dissertation describes the construction of two high precision magneto-polarimeters for performing Faraday rotation and Magnetic Circular Dichroism (MCD) measurements of polymer thin-films. There is a focus in materials science on the development of thin-film magneto-optically active materials. These materials could allow for the construction of a thin-film optical diode, an important device for next-generation photonic technology. Upon completion of the Faraday rotation spectrometer, two publications were generated from Faraday rotation measurements of novel polymer thin-film materials.

With growing interest by materials scientists in magneto-optically active transition-metal containing materials, an MCD spectrometer was constructed to study these materials. This spectrometer …

Tio2 Crystallization At Room Temperature And Preparation Of Transparent Carbon Counter Electrode For Low-Cost Dye-Sensitized Solar Cells, Muhammad Iqbal Syauqi, Afiten Rahmin Sanjaya, Mohammad Jihad Madiabu, Munawar Khalil, Jarnuzi Gunlazuardi

Makara Journal of Science

We developed a low-cost dye-sensitized solar cell (DSSC) using TiO₂ fabricated via rapid breakdown anodization (RBA) and ultrafast room-temperature crystallization (URTC). The prepared TiO₂ was deposited on a self-made fluorine-doped tin oxide (FTO) conductive glass, and the FTO/TiO₂ system was sensitized using curcumin dye. The DSSC was constructed by sandwiching the FTO/TiO₂/curcumin electrode with an I⁻/I₂ electrolyte and a transparent carbon counter electrode prepared using a liquid–liquid interface system. The characterization results showed that the TiO₂ freshly prepared via URTC was transformed into an anatase crystalline phase, which exhibited a 3.10 …

Development Of Graphene And Graphene Derivative Advanced Functional Additives: Mechanism And Application In Asphalt Formulations And Thermal Interface Management Materials, Dana Pinson

Dissertations

The overarching focus of my research is the use of graphene and graphene derivatives to enhance polymer properties. My first focus area was the prevention of oxidative degradation of asphalt through the incorporation of a graphene oxide (GO) -based nanoparticle filler to enhance oxygen barrier properties. Primary amine terminated polyisobutylene was synthesized via cationic polymerization followed by post polymerization chain end modification in a range of molecular weights and covalently grafted via the primary amine to graphene oxide aerogel (aGO) to create a polyisobutylene grafted graphene oxide (PIB-g-GO) nanoparticle. PIB-g-GO was then mixed into a substitute asphalt matrix at various …