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Full-Text Articles in Physical Sciences and Mathematics

Electrochemical Sers Study Of Benzotriazole And 3-Mercapto-1-Propanesulfonate In Acidic Solution On Copper Electrode, Yin-Fei Shen, Yan-Li Chen, Sheng-Xu Wang, Ye Zhu, Wen-Chang Wang, Min-Xian Wu, Zhi-Dong Chen Jun 2022

Electrochemical Sers Study Of Benzotriazole And 3-Mercapto-1-Propanesulfonate In Acidic Solution On Copper Electrode, Yin-Fei Shen, Yan-Li Chen, Sheng-Xu Wang, Ye Zhu, Wen-Chang Wang, Min-Xian Wu, Zhi-Dong Chen

Journal of Electrochemistry

Since the development of acid copper plating technology, the role of additives is indispensable. In addition to the main salt copper sulfate and supporting electrolyte sulfuric acid, suppressors, accelerators, levelers and chlorine ions (Cl-) are also required to be added into the plating solution. Appropriate additive system can have a significant impact on the coating or the plating solution, which can help improve the quality of the coating and increase the brightness of the coating. Through electrochemical measurement, vibrational spectroscopy, scanning probe microscopy, molecular dynamics simulation and other methods, researches have a deeper understanding in the adsorption configuration …


Study On The Effect Of Additives In The Electrodeposition Of Sn-Ag-Cu Ternary Alloy Solder, Hua Miao, Ming-Rui Li, Wen-Zhong Zou, Guo-Yun Zhou, Shou-Xu Wang, Xiao-Jing Ye, Kai Zhu Jun 2022

Study On The Effect Of Additives In The Electrodeposition Of Sn-Ag-Cu Ternary Alloy Solder, Hua Miao, Ming-Rui Li, Wen-Zhong Zou, Guo-Yun Zhou, Shou-Xu Wang, Xiao-Jing Ye, Kai Zhu

Journal of Electrochemistry

Sn-Ag-Cu ternary alloy is the most ideal substitute for Sn-Pb alloy at present, and can be prepared by electrodeposition with high production efficiency, simple equipment, easy maintenance and excellent coating performance. The coordination system of the electroplating solution was investigated through the Hull cell experiment. The type of brighteners used in the plating solution and the ratio of the two brighteners were determined through the microscopic morphologic characterization, electrochemical corrosion test and cathodic polarization curve test. In addition, the dispersant and stabilizer were studied by observing the microscopic morphology and measuring the concentration change of Sn2+ ions in the …


Development Status Of Copper Electroplating Filling Technology In Through Glass Via For 3d Interconnections, Zhi-Jing Ji, Hui-Qin Ling, Pei-Lin Wu, Rui-Yi Yu, Da-Quan Yu, Ming Li Jun 2022

Development Status Of Copper Electroplating Filling Technology In Through Glass Via For 3d Interconnections, Zhi-Jing Ji, Hui-Qin Ling, Pei-Lin Wu, Rui-Yi Yu, Da-Quan Yu, Ming Li

Journal of Electrochemistry

With the slow development of Moore's Law, the high density and miniaturization of microelectronic devices put forward higher requirements for advanced packaging technology. As a key technology in 2.5D/3D packaging, interposer technology has been extensively studied. According to different interposer materials, it is mainly divided into organic interposer, silicon interposer and glass interposer. Compared with the through silicon via (TSV) interconnection, the through glass via (TGV) interposer has received extensive attention in the 2.5D/3D advanced packaging field for its advantages of excellent high-frequency electrical characteristics, simple process, low cost, and adjustable coefficient of thermal expansion (CTE). However, the thermal conductivity …


Research Progresses Of Cobalt Interconnect And Superfilling By Electroplating In Chips, Li-Jun Wei, Zi-Han Zhou, Yun-Wen Wu, Ming Li, Su Wang Jun 2022

Research Progresses Of Cobalt Interconnect And Superfilling By Electroplating In Chips, Li-Jun Wei, Zi-Han Zhou, Yun-Wen Wu, Ming Li, Su Wang

Journal of Electrochemistry

Copper interconnect using dual damascene technology has always been the main means for metallization in the back end of line process. However, with the size effect becoming more and more obvious due to feature size reduction, copper interconnect can no longer meet the demand for high circuit speed in Post-Moore era. Following copper interconnection, cobalt interconnection in chips attracts much attention as an interconnect technology by the next generation, which has been introduced in 7 nm node of integrated circuit manufacturing and below. The electron mean free path of cobalt (~10 nm) is much shorter than copper’s (39 nm), thus …


Microstructure Of Electrodeposited Copper Foil: Discussion On The Mechanism Model Of Three-Dimensional Electrocrystallization, Ren-Zhi Liu, Ping-Ling Xie, Chong Wang Jun 2022

Microstructure Of Electrodeposited Copper Foil: Discussion On The Mechanism Model Of Three-Dimensional Electrocrystallization, Ren-Zhi Liu, Ping-Ling Xie, Chong Wang

Journal of Electrochemistry

The manufacturing of electrolytic copper foil has attracted more and more attention with the extensive applications of printed circuit board and lithium battery. The industrial scale is still extending. Compared with the developments of electroplating equipment and electroplating process, there is limited research on the mechanism of electrodeposition. This paper summarizes the manufacturing process of electrodeposited copper foil and analyzes the differences of various electroplating parameters in different electrodeposited copper technologies, and points out the important role of electrodeposition current density in the formation of copper foil. By showing and comparing the microstructures of different electrodeposited copper foils, the influences …


Introduction Of Development And Application Technology Of Organic Additives For Acid Copper Electroplating, Hao-Bin Zou, Chao-Li Tan, Wei Xiong, Dao-Lin Xi, Bin-Yun Liu Jun 2022

Introduction Of Development And Application Technology Of Organic Additives For Acid Copper Electroplating, Hao-Bin Zou, Chao-Li Tan, Wei Xiong, Dao-Lin Xi, Bin-Yun Liu

Journal of Electrochemistry

Acid copper electroplating is one of the key technologies in buildup multilayer PCB (BUM-PCB) manufacture process and the most important technique to achieve electrical interconnection between any layer and high-density interconnection in a substrate. This article introduces the research focus of organic additives used in acid copper electroplating, and developing different kinds of micro-via filling copper electroplating technique applied in various scenarios, and some other technical problems from applications. First of all, according to the chronopotentiometric (CP) experiment results, the levelers with different polymeric molecular structures exhibited various responses of cupric deposition potential along with their increased concentrations, which is …


Optimization Of Pulse Plating Additives And Plating Parameters For High Aspect Ratio Through Holes, Kai Yang, Ji-Da Chen, Shi-Jin Chen, Wei-Lian Xu, Mao-Gui Guo, Jin-Chao Liao, Zeng-Kun Wu Jun 2022

Optimization Of Pulse Plating Additives And Plating Parameters For High Aspect Ratio Through Holes, Kai Yang, Ji-Da Chen, Shi-Jin Chen, Wei-Lian Xu, Mao-Gui Guo, Jin-Chao Liao, Zeng-Kun Wu

Journal of Electrochemistry

As an important component in electronic products, printed circuit board (PCB) plays a supporting and interconnecting role for the electronic components in it. With the development of communication technology, electronic products are developing in the direction of “thin, light and small”, and high density interconnection (HDI) comes into being. Due to the high-density interconnection characteristics of HDI boards, the thickness of the board is increasing. At the same time, in order to reserve space for the laying of fine lines on the subsequent board surface, the diameter of the through holes on the board is also decreasing, so the depth-diameter …


Effect Of Sodium Alcohol Thiyl Propane Sulfonate On Electrolysis Of High Performance Copper Foil For Lithium Ion Batteries, Sen Yang, Wen-Chang Wang, Ran Zhang, Shui-Ping Qin, Min-Xian Wu, Naotoshi Mitsuzaki, Zhi-Dong Chen Jun 2022

Effect Of Sodium Alcohol Thiyl Propane Sulfonate On Electrolysis Of High Performance Copper Foil For Lithium Ion Batteries, Sen Yang, Wen-Chang Wang, Ran Zhang, Shui-Ping Qin, Min-Xian Wu, Naotoshi Mitsuzaki, Zhi-Dong Chen

Journal of Electrochemistry

Electrolytic copper foils have been widely used in printed circuit boards and lithium-ion batteries due to their simple production process and high economic value. In the process of electrolysis foil making, additives can greatly improve the performance of electrolytic copper foils. In this work, the copper foils were prepared in a self-designed plate electrodeposition device of which the operating principles were in accordance with those of actual industrial production. A series of the Virgin Make-up Solution (VMS: 312.5 g·L-1 CuSO4·5H2O, 100 g·L-1 H2SO4, 50 mg·L-1 Cl-) containing …


On The Exact Helium Wave Function Expansion, Carl W. David Jun 2022

On The Exact Helium Wave Function Expansion, Carl W. David

Chemistry Education Materials

A 1S wave function’s expansion for 2 electron atoms and ions is obtained and the leading coefficients are reported.


Polychlorinated Organic Contaminants In Baleen From North Pacific Ocean Whales, Briana R. Coulter Jun 2022

Polychlorinated Organic Contaminants In Baleen From North Pacific Ocean Whales, Briana R. Coulter

All HCAS Student Capstones, Theses, and Dissertations

Persistent organic pollutants (POP) have been detected and analyzed in various baleen whale tissues (blubber, muscles, liver, etc.) This study concentrated on detecting 7 polychlorinated biphenyls (PCB) and 14 organochlorine pesticides from baleen, a baleen whale tissue never before analyzed for POPs. These data were used to investigate temporal and geographic trends by sampling at every 1 cm interval along the length of the baleen plate. Four species of baleen whales stranded in the North Pacific Ocean were included in this study: gray (n=2), humpback (n=2), minke (n=1), and blue (n=1) whales. Organic contaminant concentrations were analyzed with respect to …


Site-Directed Mutagenesis Of Serine-72 Reveals The Location Of The Fructose 6-Phosphate Regulatory Site Of The Agrobacterium Tumefaciensadp-Glucose Pyrophosphorylase, Mashael Alghamdi Dr., Rania Ali Z Hussien, Yuanzhang Zheng, Hiral Patel, Matias D. Asencion Diez, Alberto A. Iglesias, Dali Liu, Miguel A. Ballicora Jun 2022

Site-Directed Mutagenesis Of Serine-72 Reveals The Location Of The Fructose 6-Phosphate Regulatory Site Of The Agrobacterium Tumefaciensadp-Glucose Pyrophosphorylase, Mashael Alghamdi Dr., Rania Ali Z Hussien, Yuanzhang Zheng, Hiral Patel, Matias D. Asencion Diez, Alberto A. Iglesias, Dali Liu, Miguel A. Ballicora

Chemistry: Faculty Publications and Other Works

The allosteric regulation of ADP–glucose pyrophosphorylase is critical for the biosynthesis of glycogen in bacteria and starch in plants. The enzyme from Agrobacterium tumefaciens is activated by fructose 6-phosphate (Fru6P) and pyruvate (Pyr). The Pyr site has been recently found, but the site where Fru6P binds has remained unknown. We hypothesize that a sulfate ion previously found in the crystal structure reveals a part of the regulatory site mimicking the presence of the phosphoryl moiety of the activator Fru6P. Ser72 interacts with this sulfate ion and, if the hypothesis is correct, Ser72 would affect the interaction with Fru6P and activation …


Carbon Nanotube Encapsulated Metal Selenide Nanostructures For Efficient Electrocatalytic Oxygen Evolution Reaction, Harish Singh, Wipula P.R. Liyanage, Manashi Nath Jun 2022

Carbon Nanotube Encapsulated Metal Selenide Nanostructures For Efficient Electrocatalytic Oxygen Evolution Reaction, Harish Singh, Wipula P.R. Liyanage, Manashi Nath

Chemistry Faculty Research & Creative Works

Nickel selenide nanowires were grown inside carbon nanotubes through in situ encapsulation via one-step chemical vapor deposition. These NiSe2@CNT nanohybrids showed excellent electrocatalytic activity for water splitting with a low overpotential of 260 mV at 10 mA cm−2, high current density, and extended stability owing to the synergistic effect between NiSe2 and CNTs.


Multifunctional Nanomaterials For Energy Applications, Simas Rackauskas, Federico Cesano, Mohammed Jasim Uddin Jun 2022

Multifunctional Nanomaterials For Energy Applications, Simas Rackauskas, Federico Cesano, Mohammed Jasim Uddin

Chemistry Faculty Publications and Presentations

No abstract provided.


Temperature-Resolved Surface Infrared Spectroscopy Of Co On Rh(111) And (2 × 1)-O/Rh(111), Elizabeth A. Jamka, Maxwell Z. Gillum, Christina N. Grytsyshyn-Giger, Faith J. Lewis, Daniel Killelea Jun 2022

Temperature-Resolved Surface Infrared Spectroscopy Of Co On Rh(111) And (2 × 1)-O/Rh(111), Elizabeth A. Jamka, Maxwell Z. Gillum, Christina N. Grytsyshyn-Giger, Faith J. Lewis, Daniel Killelea

Chemistry: Faculty Publications and Other Works

Heterogeneously catalyzed reactions over transition metal surfaces are pillars of chemical industry and account for a significant fraction of the global energy demand. CO oxidation provides insight into the relative reactivity of various oxygenaceous surface phases, and it is necessary to first understand where it binds to the surface and the nature of the local environment to develop robust mechanistic pictures of the reaction. Surface IR spectroscopy is a quantitative technique that also provides information about the binding sites and chemical environments of the adsorbed CO molecules. Here, we report results from a study of CO sticking to clean Rh(111) …


Improved Performance Of Silica-Supported La0.5Ba0.5Feo3 In The Reverse Water Gas Shift - Chemical Looping Process For Carbon Dioxide Reduction – A Density Functional Theory Study, Jiawei Guo Jun 2022

Improved Performance Of Silica-Supported La0.5Ba0.5Feo3 In The Reverse Water Gas Shift - Chemical Looping Process For Carbon Dioxide Reduction – A Density Functional Theory Study, Jiawei Guo

USF Tampa Graduate Theses and Dissertations

Global warming is increasingly obvious, and the reduction of greenhouse gases is an effective way to heal. Increasing the efficiency of catalysts that is applied in the industry can significantly reduce the emission of greenhouse gases. Reverse water gas shift chemical looping (RWGS-CL) is a promising reaction to convert CO2 to CO. La0.5Ba0.5FeO3 (LBF) is a good candidate for RWGS-CL, which shows increased conversion yield when supported on silica. This research focuses on identifying the mechanism of RWGS-CL via silica-supported LBF by exploring the oxygen vacancy formation energy (EO-vac). Density Functional Theory (DFT) is a powerful computational method to solve …


Synthesis, Structure-Activity And Mechanism Studies Of Poly(Guanylurea)S Against Mycobacteria, Michelle M. Miranda Jun 2022

Synthesis, Structure-Activity And Mechanism Studies Of Poly(Guanylurea)S Against Mycobacteria, Michelle M. Miranda

FIU Electronic Theses and Dissertations

Tuberculosis (TB) continues to be a serious threat worldwide, especially in developing countries. Current first-line treatment for TB infections is a multidrug regimen for 4-9 months; if not taken as prescribed, drug-resistant TB can emerge. Novel drugs with unconventional targets are warranted to lessen the lengthy and four-drug treatment. Antimicrobial polymers mimicking naturally occurring antimicrobial peptides (AMPs) have gained much attention due to their enzymatic stability, tunability, cost-effectiveness, and unique mode of action - directly or indirectly - on bacterial membrane. However, selectivity and toxicity have limited their biological applications. Previously, our group synthesized a novel class of antimicrobial polymers, …


Examining Metal Contents In Primary And Secondhand Aerosols Released By Electronic Cigarettes, Kashala Fabrice Kapiamba, Weixing Hao, Stephen Adom, Wenyan Liu, Yue-Wern Huang, Yang Wang Jun 2022

Examining Metal Contents In Primary And Secondhand Aerosols Released By Electronic Cigarettes, Kashala Fabrice Kapiamba, Weixing Hao, Stephen Adom, Wenyan Liu, Yue-Wern Huang, Yang Wang

Chemistry Faculty Research & Creative Works

The usage of electronic cigarettes (ECs) has surged since their invention two decades ago. However, to date, the health effects of EC aerosol exposure are still not well understood because of insufficient data on the chemical composition of EC aerosols and the corresponding evidence of health risks upon exposure. Herein, we quantified the metals in primary and secondhand aerosols generated by three brands of ECs. By combining aerosol filter sampling and inductively coupled plasma mass spectrometry (ICP-MS), we assessed the mass of metals as a function of EC flavoring, nicotine concentration, device power, puff duration, and aging of the devices. …


Exploring Structure-Function Relationship In Small-Molecular Catalysts Using Computational And Experimental Methodologies, Avik Bhattacharjee Jun 2022

Exploring Structure-Function Relationship In Small-Molecular Catalysts Using Computational And Experimental Methodologies, Avik Bhattacharjee

Dissertations and Theses

Molecular modeling is a useful tool in the field of catalyst design for various processes. The use of Density Functional Theory (DFT) is routine in almost every discipline of chemistry. This allows for a deeper understanding of a molecular system even in situations where implementation of an experimental technique is unfeasible. However, without the right choice of theory and insufficient description, the model becomes susceptible to produce ambiguous results. This often leads to poor correlation with experimental findings hence an incomplete understanding of the system under study. Hence, to acquire a thorough knowledge of the intricacies involved in a system, …


Chiral Recognition Of Hydantoin Derivatives Enabled By Tetraaza Macrocyclic Chiral Solvating Agents Using 1H Nmr Spectroscopy, Jie Wen, Lei Feng, Hongmei Zhao, Li Zheng, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang Jun 2022

Chiral Recognition Of Hydantoin Derivatives Enabled By Tetraaza Macrocyclic Chiral Solvating Agents Using 1H Nmr Spectroscopy, Jie Wen, Lei Feng, Hongmei Zhao, Li Zheng, Pericles Stavropoulos, Lin Ai, Jiaxin Zhang

Chemistry Faculty Research & Creative Works

Enantiomers of a series of hydantoin derivatives were prepared from d- and l-amino acids with p-tolyl isocyanate and 3,5-bis(trifluoromethyl)phenyl isocyanate as guests for chiral recognition by 1H NMR spectroscopy. Meanwhile, several tetraaza macrocyclic compounds were synthesized as chiral solvating agents from d-phenylalanine and (1S,2S)-(+)-1,2-diaminocyclohexane. An uncommon enantiomeric discrimination has been successfully established for hydantoin derivatives, representatives of five-membered N,N-heterocycles, in the presence of tetraaza macrocyclic chiral solvating agents (TAMCSAs) 1a-1c by means of 1H NMR spectroscopy. Several unprecedented nonequivalent chemical shifts (up to 1.309 ppm) were observed in the split 1H NMR spectra. To evaluate practical applications …


A Multi‑Analytical Approach To Identify Red Colorants On Woodblock Prints Attributed To Suzuki Harunobu, Lyndsay Nichole Kissell, Trine K. Quady, Dario Durastanti, Samantha Springer, Jeannie Kenmotsu, Tami Lasseter Clare Jun 2022

A Multi‑Analytical Approach To Identify Red Colorants On Woodblock Prints Attributed To Suzuki Harunobu, Lyndsay Nichole Kissell, Trine K. Quady, Dario Durastanti, Samantha Springer, Jeannie Kenmotsu, Tami Lasseter Clare

Chemistry Faculty Publications and Presentations

Red organic dye identification is an important topic for conservation of Japanese ukiyo-e prints. Of particular interest are the works of Suzuki Harunobu, who was working at the inception of full-color printmaking. These prints were made on thin kōzo paper and woodblock printed with semi-transparent to opaque regions of dye(s) and/ or pigment(s) mixed with binder. This study used imaging analysis, X-ray fluorescence (XRF), Raman, and surfaceenhanced Raman spectroscopies (SERS) to identify the red dyes and pigments on Harunobu prints in the collection of the Portland Art Museum. Through image analysis (visible, UV, and IR illuminations), 23 prints were categorized …


Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darrone Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye Jun 2022

Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darrone Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye

Faculty Publications

A new niobium-doped inorganic scintillating oxyfluoride, Rb4Ge5O9F6:Nb, was synthe-sized in single crystal form by high-temperature flux growth. The host structure, Rb4Ge5O9F6, crystal-lizes in the orthorhombic space groupPbcnwith lattice parametersa= 6.98430(10)Å,b= 11.7265(2) Å,andc= 19.2732(3) Å, consisting of germanium oxyfluoride layers made up of Ge3O9units connectedby GeO3F3octahedra. In its pure form, Rb4Ge5O9F6shows neither luminescence nor scintillation butwhen doped with niobium, Rb4Ge5O9F6:Nb exhibits bright blue luminescence and scintillation. Theisostructural doped structure, Rb4Ge5O9F6:Nb, crystallizes in the orthorhombic space groupPbcnwith lattice parametersa= 6.9960(3) Å,b= 11.7464(6) Å, andc= 19.3341(9) Å. X-ray absorption nearedge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements suggestthat the niobium …


Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darren Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye Jun 2022

Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darren Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye

Faculty Publications

A new niobium-doped inorganic scintillating oxyfluoride, Rb4Ge5O9F6:Nb, was synthesized in single crystal form by high-temperature flux growth. The host structure, Rb4Ge5O9F6, crystallizes in the orthorhombic space group Pbcn with lattice parameters a = 6.98430(10) Å, b = 11.7265(2) Å, and c = 19.2732(3) Å, consisting of germanium oxyfluoride layers made up of Ge3O9 units connected by GeO3F3 octahedra. In its pure form, Rb4Ge5O9F6 shows neither luminescence nor scintillation but when doped …


Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darren Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye Jun 2022

Luminescence And Scintillation In The Niobium Doped Oxyfluoride Rb4Ge5O9F6:Nb, Darren Carone, Vladislav V. Klepov, Scott T. Misture, Joseph C. Schaeperkoetter, Luiz G. Jacobsohn, Mina Aziziha, Juliano Schorne-Pinto, Stuart A. J. Thomson, Adrian T. Hines, Theodore M. Besmann, Hans Conrad Zur Loye

Faculty Publications

A new niobium-doped inorganic scintillating oxyfluoride, Rb4Ge5O9F6:Nb, was synthesized in single crystal form by high-temperature flux growth. The host structure, Rb4Ge5O9F6, crystallizes in the orthorhombic space group Pbcn with lattice parameters a = 6.98430(10) Å, b = 11.7265(2) Å, and c = 19.2732(3) Å, consisting of germanium oxyfluoride layers made up of Ge3O9 units connected by GeO3F3 octahedra. In its pure form, Rb4Ge5O9F6 shows neither luminescence nor scintillation but when doped …


Characterization Of Competing Halogen- And Hydrogen-Bonding Motifs In Simple Mixed Dimers Of Hcn And Hx (X = F, Cl, Br, And I), Morgan A. Perkins, Gregory S. Tschumper Jun 2022

Characterization Of Competing Halogen- And Hydrogen-Bonding Motifs In Simple Mixed Dimers Of Hcn And Hx (X = F, Cl, Br, And I), Morgan A. Perkins, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

This work performs the first systematic comparison of hydrogen- and halogen-bonded configurations of the HCN/HX mixed dimer, where X = F, Cl, Br, and I. Eleven different minima have been characterized for these four heterogeneous dimers near the CCSD(T) complete basis set (CBS) limit. For each complex, two different hydrogen-bonded minima were identified: the global minimum where HX acts as the hydrogen bond donor and a local minimum where HX acts as the hydrogen bond acceptor. A halogen-bonded local minimum was also identified for all but the fluorine mixed dimer. To the best of our knowledge, three of the minima …


Enhancing Vanadium Redox Battery Performance Using Tungsten-Bismuth-Based Oxide Nanostructures As Electrode Modifiers, Taher Al Najjar Jun 2022

Enhancing Vanadium Redox Battery Performance Using Tungsten-Bismuth-Based Oxide Nanostructures As Electrode Modifiers, Taher Al Najjar

Theses and Dissertations

Renewable energy power plants require high efficiency conversion and storage systems that can store high amounts of energy and can be integrated with the electrical grid. Vanadium redox flow batteries are very promising for this application. However, one major drawback of VRFBs is their low power density which means that right now they cannot replace non-renewable energy sources. Different carbon materials are used as electrodes in VRFBs and each carbon material affects the battery’s performance in a different way. Modification of these electrodes can increase the power density of the battery. Some metal oxides like tungsten oxide can enhance vanadium …


Stereocontrolled Access To Δ-Lactone-Fused-Γ-Lactams Bearing Angular Benzylic Quaternary Stereocenters, Timothy K. Beng, Morgan J. Rodriguez, Claire Borg Jun 2022

Stereocontrolled Access To Δ-Lactone-Fused-Γ-Lactams Bearing Angular Benzylic Quaternary Stereocenters, Timothy K. Beng, Morgan J. Rodriguez, Claire Borg

All Faculty Scholarship for the College of the Sciences

C-fused γ-lactam-lactones are resident in several bioactive molecules, including anticancer agents such as omuralide. In this embodiment, we report mild conditions for the catalytic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids. The use of dichloromethane as the solvent and Ph3PS as the catalyst led to predominant 6-endo-trig cyclization and furnished the trans-fused-γ-lactam-δ-lactones. The transformation is modular, regioselective, chemoselective, and diastereoselective. The γ-lactam-δ-lactones bear angular quaternary benzylic stereocenters, which is noteworthy since the presence of a quaternary carbon in bioactive small molecules often promotes an element of conformational restriction that imparts potency, selectivity, and metabolic stability. The …


Emerging Technologies: Empowering People To Capture, Share And Transfer Tacit Knowledge, Donncadh J. Nagle, Melanie J. Adams Jun 2022

Emerging Technologies: Empowering People To Capture, Share And Transfer Tacit Knowledge, Donncadh J. Nagle, Melanie J. Adams

Level 3

ICH Q10 was published in 2008, and presented a model for an effective Pharmaceutical Quality System (PQS). However, the industry still has some way to go in embracing and implementing its principles in order to achieve greater product realisation, to establish and maintain a state of control, and to facilitate continual improvement.

ICH Q10 introduced us to two key enablers: Knowledge Management (KM) and Quality Risk Management (QRM).[1] While the pharmaceutical industry has made progress in implementing the principles of QRM since 2008, there has been significantly slower progress in implementing knowledge management practices. However, there may be solutions …


Managing Risk And Knowledge: Frameworks To Guide Knowledge-Enabled Technology Transfer, Martin Lipa Dr, Anne Greene Jun 2022

Managing Risk And Knowledge: Frameworks To Guide Knowledge-Enabled Technology Transfer, Martin Lipa Dr, Anne Greene

Level 3

Technology transfer is not only about the transfer of technology, but also about the transfer of knowledge, as evidenced by definitions of KM within the biopharma industry and beyond. However, knowledge transfer is often not well structured and its effectiveness – in particular for tacit knowledge (i.e., know how) – is an opportunity for improvement which can lead to many benefits. This article profiles recent research into the topic of improving knowledge transfer during technology transfer and presents several recently developed frameworks for improving such. The article furthermore explains how the frameworks can be co-deployed in support of robust knowledge …


Preparation Of Carbon Aerogels From Polymer-Cross-Linked Xerogel Powders Without Supercritical Fluid Drying And Their Application In Highly Selective Co2adsorption, Rushi U. Soni, Vaibhav A. Edlabadkar, Daniel Greenan, Parwani M. Rewatkar, Nicholas Leventis, Chariklia Sotiriou-Leventis Jun 2022

Preparation Of Carbon Aerogels From Polymer-Cross-Linked Xerogel Powders Without Supercritical Fluid Drying And Their Application In Highly Selective Co2adsorption, Rushi U. Soni, Vaibhav A. Edlabadkar, Daniel Greenan, Parwani M. Rewatkar, Nicholas Leventis, Chariklia Sotiriou-Leventis

Chemistry Faculty Research & Creative Works

Carbon aerogels are well-known materials for their high porosity and high surface areas. They are typically made from pyrolysis of carbonizable polymeric aerogels. Here, we report an alternative route to monolithic carbon aerogels starting from xerogel powders. Use of powders speeds up solvent exchanges along sol-gel processing, and xerogelling bypasses the supercritical fluid drying step that is needed for making polymeric aerogels. Overall, this alternative route results in time, energy, and materials efficiency in the fabrication of carbon aerogels. Specifically, polymer-cross-linked silica xerogel powders were prepared via free-radical surface-initiated polymerization of acrylonitrile (AN) on a suspension of silica particles derived …


Calcium Bistriflimide-Mediated Sulfur(Vi)–Fluoride Exchange (Sufex): Mechanistic Insights Toward Instigating Catalysis, Brian Han, Samuel R. Khasnavis, Matthew Nwerem, Michael Bertagna, Nicholas D. Ball, O. Maduka Ogba Jun 2022

Calcium Bistriflimide-Mediated Sulfur(Vi)–Fluoride Exchange (Sufex): Mechanistic Insights Toward Instigating Catalysis, Brian Han, Samuel R. Khasnavis, Matthew Nwerem, Michael Bertagna, Nicholas D. Ball, O. Maduka Ogba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report a mechanistic investigation of calcium bistriflimide-mediated sulfur(VI)–fluoride exchange (SuFEx) between sulfonyl fluorides and amines. We determine the likely pre-activation resting state─a calcium bistriflimide complex with ligated amines─thus allowing for corroborated calculation of the SuFEx activation barrier at ∼21 kcal/mol, compared to 21.5 ± 0.14 kcal/mol derived via kinetics experiments. Transition state analysis revealed: (1) a two-point calcium-substrate contact that activates the sulfur(VI) center and stabilizes the leaving fluoride and (2) a 1,4-diazabicyclo[2.2.2]octane additive that provides Brønsted-base activation of the nucleophilic amine. Stable Ca–F complexes upon sulfonamide formation are likely contributors to inhibited catalytic turnover, and a proof-of-principle redesign …