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- Mass spectrometry (5)
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- CONDENSATION (2)
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- ABSORPTION FINE-STRUCTURE; NEEL TEMPERATURE; FERRITE (1)
- ABSORPTION FINE-STRUCTURE; NI-ZN NANOFERRITE; SATURATION MAGNETIZATION; REVERSE MICELLES; NANOPARTICLES; SIZE (1)
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Articles 1 - 30 of 96
Full-Text Articles in Physical Sciences and Mathematics
Ultrafast Dynamics Of Nitro−Nitrite Rearrangement And Dissociation In Nitromethane Cation, Mi'kayla D. Word, Hugo Andres Lopez Pena, Derrick Ampadu Boateng, Shane L. Mcpherson, Gennady L. Gutsev, Lavrenty Gutsev, Ka Un Lao, Katharine M. Tibbetts
Ultrafast Dynamics Of Nitro−Nitrite Rearrangement And Dissociation In Nitromethane Cation, Mi'kayla D. Word, Hugo Andres Lopez Pena, Derrick Ampadu Boateng, Shane L. Mcpherson, Gennady L. Gutsev, Lavrenty Gutsev, Ka Un Lao, Katharine M. Tibbetts
Chemistry Publications
We report new insights into the ultrafast rearrange- ment and dissociation dynamics of nitromethane cation (NM+) using pump−probe measurements, electronic structure calculations, and ab initio molecular dynamics simulations. The “roaming” nitro−nitrite rearrangement (NNR) pathway involving large- amplitude atomic motion, which has been previously described for neutral nitromethane, is demonstrated for NM+. Excess energy resulting from initial population of the electronically excited D2 state of NM+ upon strong-field ionization provides the necessary energy to initiate NNR and subsequent dissociation into NO+. Both pump−probe measurements and molecular dynamics simulations are consistent with the completion of NNR within 500 fs of ionization with …
Generation Of Nanomaterials By Reactive Laser Synthesis In Liquid, Laysa M. Frias Batista, Ashish B. Nag, Victoria K. Meader, Katharine M. Tibbetts
Generation Of Nanomaterials By Reactive Laser Synthesis In Liquid, Laysa M. Frias Batista, Ashish B. Nag, Victoria K. Meader, Katharine M. Tibbetts
Chemistry Publications
Nanomaterials with tailored structures and surface chemistry are in high demand, as these materials play increasingly important roles in biology, catalysis, energy storage, and manu- facturing. Their heightened demand has attracted attention towards the development of syn- thesis routes, particularly, laser-synthesis techniques. These efforts drove the refinement of laser ablation in liquid (LAL) and related methods over the past two decades, and have led to the emergence of reactive laser-synthesis techniques that exploit these methods’ character- istic, non-equilibrium conditions. Reactive laser-synthesis approaches foster unique chemical reactions that enable the formation of composite products like multimetallic nanoparticles, supported nanostructures, and complex …
Reversible Electrowetting Transitions On Superhydrophobic Surfaces, D. Vanzo, A. Luzar, D. Bratko
Reversible Electrowetting Transitions On Superhydrophobic Surfaces, D. Vanzo, A. Luzar, D. Bratko
Chemistry Publications
Electric field applied across the interface has been shown to enable transitions from Cassie to Wenzel state on superhydrophobic surfaces with miniature corrugations. Molecular Dynamics (MD) simulations manifest the possibility of reversible cycling between the two states when narrow surface wells support spontaneous expulsion of water in the absence of the field. With approximately 1 nm sized wells between the surface asperities, response times to changes of electric field are of O(0.1) ns, allowing up to GHz frequency of the cycle. Because of orientation preferences of interfacial water in contact with the solid, the phenomenon depends on the polarity of …
Controlling The Morphology Of Copper-Silica Nanocomposites From Laser Ablation In Liquid, Mallory John, Katharine M. Tibbetts
Controlling The Morphology Of Copper-Silica Nanocomposites From Laser Ablation In Liquid, Mallory John, Katharine M. Tibbetts
Chemistry Publications
No abstract provided.
From Neutral Aniline To Aniline Trication: A Computational And Experimental Study, G. L. Gutsev, H. A. López Peña, S. L. Mcpherson, Derrick Ampadu Boateng, B. R. Ramachandran, L. G. Gutsev, Katharine M. Tibbetts
From Neutral Aniline To Aniline Trication: A Computational And Experimental Study, G. L. Gutsev, H. A. López Peña, S. L. Mcpherson, Derrick Ampadu Boateng, B. R. Ramachandran, L. G. Gutsev, Katharine M. Tibbetts
Chemistry Publications
We report density functional theory computations and photoionization mass spectrometry measurements of aniline and its positively charged ions. The geometrical structures and properties of the neutral, singly, doubly, and triply positively charged aniline are computed using density functional theory with the generalized gradient approximation. At each charge, there are multiple isomers closely spaced in total energy. Whereas the lowest energy states of both neutral and cation have the same topology C6H5–NH2, the dication and trication have the C5NH5–CH2 topology with the nitrogen atom in the meta and para positions, …
Dissociation Of Singly And Multiply Charged Nitromethane Cations: Femtosecond Laser Mass Spectrometry And Theoretical Modeling, G. L. Gutsev, S. L. Mcpherson, Hugo A. López Peña, Derrick Ampadu Boateng, L. G. Gutsev, B. R. Ramachandran, Katharine M. Tibbetts
Dissociation Of Singly And Multiply Charged Nitromethane Cations: Femtosecond Laser Mass Spectrometry And Theoretical Modeling, G. L. Gutsev, S. L. Mcpherson, Hugo A. López Peña, Derrick Ampadu Boateng, L. G. Gutsev, B. R. Ramachandran, Katharine M. Tibbetts
Chemistry Publications
Dissociation pathways of singly- and multiply charged gas-phase nitromethane cations were investigated with strong-field laser photoionization mass spectrometry and density functional theory computations. There are multiple isomers of the singly charged nitromethane radical cation, several of which can be accessed by rearrangement of the parent CH3–NO2 structure with low energy barriers. While direct cleavage of the C–N bond from the parent nitromethane cation produces NO2+ and CH3+, rearrangement prior to dissociation accounts for fragmentation products including NO+, CH2OH+, and CH2NO+. Extensive Coulomb explosion in fragment ions observed at high laser intensity indicates that rapid dissociation of multiply charged nitromethane cations …
Mechanism Of Nickel Phyllosilicate Formation By Laser Ablation In Liquid, Mallory G. John, Katharine M. Tibbetts
Mechanism Of Nickel Phyllosilicate Formation By Laser Ablation In Liquid, Mallory G. John, Katharine M. Tibbetts
Chemistry Publications
No abstract provided.
High-Pressure Infiltration−Expulsion Of Aqueous Nacl In Planar Hydrophobic Nanopores, S. Zamfir, F. Moucka, D. Bratko
High-Pressure Infiltration−Expulsion Of Aqueous Nacl In Planar Hydrophobic Nanopores, S. Zamfir, F. Moucka, D. Bratko
Chemistry Publications
Pressure-driven permeation of water in a poorly wettable material results in a conversion of mechanical work into surface free energy representing a new form of energy storage, or absorption. When water is replaced by a concentrated electrolyte solution, the storage capacity of a nanoporous medium becomes comparable to high-end supercapacitors. The addition of salt can also reduce the hysteresis of the infiltration/expulsion cycle. Our molecular simulations provide a theoretical perspective into the mechanisms involved in the process, and underlying structures and interactions in compressed nanoconfined solutions. Specifically, we consider aqueous NaCl in planar confinements of widths of 1.0 nm and …
One-Step Femtosecond Laser Ablation Synthesis Of Sub-3 Nm Gold Nanoparticles Stabilized By Silica, Mallory G. John, Katharine M. Tibbetts
One-Step Femtosecond Laser Ablation Synthesis Of Sub-3 Nm Gold Nanoparticles Stabilized By Silica, Mallory G. John, Katharine M. Tibbetts
Chemistry Publications
No abstract provided.
Conserved Vibrational Coherence In The Ultrafast Rearrangement Of 2-Nitrotoluene Radical Cation, Derrick Ampadu Boateng, Mi'kayla D. Word, Lavrenty Gutsev, Puru Jena, Katharine M. Tibbetts
Conserved Vibrational Coherence In The Ultrafast Rearrangement Of 2-Nitrotoluene Radical Cation, Derrick Ampadu Boateng, Mi'kayla D. Word, Lavrenty Gutsev, Puru Jena, Katharine M. Tibbetts
Chemistry Publications
2-Nitrotoluene (2-NT) is a good model for both photolabile protecting groups for organic synthesis and the military explosive 2,4,6-trinitrotoluene (TNT). In addition to the direct C−NO2 bond-cleavage reaction that initiates detonation in TNT, 2-NT undergoes an H atom attack reaction common to the photolabile 2-nitrobenzyl group, which forms the aci-nitro tautomer. In this work, femtosecond pump−probe measure- ments with mass spectrometric detection and density functional theory (DFT) calculations demonstrate that the initially prepared vibrational coherence in the 2-NT radical cation (2- NT+) is preserved following H atom attack. Strong-field adiabatic ionization is used to prepare 2-NT+, which can overcome a …
Probing Coherent Vibrations Of Organic Phosphonate Radical Cations With Femtosecond Time-Resolved Mass Spectrometry, Derrick Ampadu Boateng, Mi'kayla D. Word, Katharine M. Tibbetts
Probing Coherent Vibrations Of Organic Phosphonate Radical Cations With Femtosecond Time-Resolved Mass Spectrometry, Derrick Ampadu Boateng, Mi'kayla D. Word, Katharine M. Tibbetts
Chemistry Publications
Organic phosphates and phosphonates are present in a number of cellular components that can be damaged by exposure to ionizing radiation. This work reports femtosecond time-resolved mass spectrometry (FTRMS) studies of three organic phosphonate radical cations that model the DNA sugar-phosphate backbone: dimethyl methylphosphonate (DMMP), diethyl methylphosphonate (DEMP), and diisopropyl methylphosphonate (DIMP). Upon ionization, each molecular radical cation exhibits unique oscillatory dynamics in its ion yields resulting from coherent vibrational excitation. DMMP has particularly well-resolved 45 fs (732 ± 28 cm−1) oscillations with a weak feature at 610–650 cm−1, while DIMP exhibits bimodal oscillations with a period of ∼55 fs …
Single-Step Fret-Based Detection Of Femtomoles Dna, Kumar Sapkota, Anisa Kaur, Caleb Donkoh-Moore, Soma Dhakal
Single-Step Fret-Based Detection Of Femtomoles Dna, Kumar Sapkota, Anisa Kaur, Caleb Donkoh-Moore, Soma Dhakal
Chemistry Publications
Sensitive detection of nucleic acids and identification of single nucleotide polymorphism (SNP) is crucial in diagnosis of genetic diseases. Many strategies have been developed for detection and analysis of DNA, including fluorescence, electrical, optical, and mechanical methods. Recent advances in fluorescence resonance energy transfer (FRET)-based sensing have provided a new avenue for sensitive and quantitative detection of various types of biomolecules in simple, rapid, and recyclable platforms. Here, we report single-step FRET-based DNA sensors designed to work via a toehold-mediated strand displacement (TMSD) process, leading to a distinct change in the FRET efficiency upon target binding. Using single-molecule FRET (smFRET), …
Multifaceted Water Dynamics In Spherical Nanocages, M. Von Domaros, D. Bratko, B. Kirchner, G. Hummer, A. Luzar
Multifaceted Water Dynamics In Spherical Nanocages, M. Von Domaros, D. Bratko, B. Kirchner, G. Hummer, A. Luzar
Chemistry Publications
We present a new method to study position- dependent, anisotropic diffusion tensors inside spherically confined systems—a geometry that is common to many chemical nanoreactors. We use this method to elucidate the surprisingly rich solvent dynamics of confined water. The spatial variation of the strongly anisotropic diffusion predicted by the model agrees with the results of explicit molecular dynamics simulations. The same approach can be directly transferred to the transport of solutes to and from reaction sites located at nanoreactor interfaces. We com- plement our study by a detailed analysis of wa- ter hydrogen bond kinetics, which is intimately coupled to …
Anisotropic Structure And Dynamics Of Water Under Static Electric Fields, M. Shafiei, M. Von Domaros, D. Bratko, A. Luzar
Anisotropic Structure And Dynamics Of Water Under Static Electric Fields, M. Shafiei, M. Von Domaros, D. Bratko, A. Luzar
Chemistry Publications
We study the structure and dynamics of water subject to a range of static external electric fields, using molecular dynamics simulations. In particular, we monitor the changes in hydrogen bond kinetics, reorientation dynamics, and translational motions of water molecules. We find that water molecules translate and rotate slower in elec- tric fields, because the tendency to reinstate the aligned orientation reduces the prob- ability of finding a new hydrogen bond partner and hence increases the probability of reforming already ruptured bonds. Furthermore, dipolar alignment of water mole- cules with the field results in structural and dynamic anisotropies even though the …
Coherent Vibrational And Dissociation Dynamics Of Polyatomic Radical Cations, Katharine M. Tibbetts
Coherent Vibrational And Dissociation Dynamics Of Polyatomic Radical Cations, Katharine M. Tibbetts
Chemistry Publications
The ultrafast dynamics of polyatomic radical cat- ions contribute to important processes including energy transfer in photovoltaics, electron transfer in photocataly- sis, radiation-induced DNA damage, and chemical reac- tions in the upper atmosphere and space. Probing these dynamics in the gas phase is challenging due to the rapid dissociation of polyatomic radical cations following elec- tron removal, which arises from excess electronic excita- tion of the molecule during the ionization process. This Concept article introduces the reader to how the pump- probe technique of femtosecond time-resolved mass spectrometry (FTRMS) can overcome this challenge to capture coherent vibrational dynamics on the …
Single-Molecule Analysis Of I-Motif Within Self-Assembled Dna Duplexes And Nanocircles, Anoja Megalathan, Bobby D. Cox, Peter D. Wilkerson, Anisa Kaur, Kumar Sapkota, Joseph E. Reiner, Soma Dhakal
Single-Molecule Analysis Of I-Motif Within Self-Assembled Dna Duplexes And Nanocircles, Anoja Megalathan, Bobby D. Cox, Peter D. Wilkerson, Anisa Kaur, Kumar Sapkota, Joseph E. Reiner, Soma Dhakal
Chemistry Publications
The cytosine (C)-rich sequences that can fold into tetraplex structures known as i-motif are prevalent in genomic DNA. Recent studies of i-motif–forming sequences have shown increasing evidence of their roles in gene regulation. However, most of these studies have been performed in short single-stranded oligonucleotides, far from the intracellular environment. In cells, i-motif–forming sequences are flanked by DNA duplexes and packed in the genome. Therefore, exploring the conformational dynamics and kinetics of i-motif under such topologically constrained environments is highly relevant in predicting their biological roles. Using single-molecule fluorescence analysis of self-assembled DNA duplexes and nanocircles, we show that the …
Homologous Recombination Under The Single-Molecule Fluorescence Microscope, Dalton R. Gibbs, Soma Dhakal
Homologous Recombination Under The Single-Molecule Fluorescence Microscope, Dalton R. Gibbs, Soma Dhakal
Chemistry Publications
Homologous recombination (HR) is a complex biological process and is central to meiosis and for repair of DNA double-strand breaks. Although the HR process has been the subject of intensive study for more than three decades, the complex protein–protein and protein–DNA interactions during HR present a significant challenge for determining the molecular mechanism(s) of the process. This knowledge gap is largely because of the dynamic interactions between HR proteins and DNA which is difficult to capture by routine biochemical or structural biology methods. In recent years, single-molecule fluorescence microscopy has been a popular method in the field of HR to …
Molecular Polarizability In Open Ensemble Simulations Of Aqueous Nanoconfinements Under Electric Field, F. Moucka, S. Zamfir, D. Bratko, A. Luzar
Molecular Polarizability In Open Ensemble Simulations Of Aqueous Nanoconfinements Under Electric Field, F. Moucka, S. Zamfir, D. Bratko, A. Luzar
Chemistry Publications
Molecular polarization at aqueous interfaces involves fast degrees of freedom that are often averaged-out in atomistic-modeling approaches. The resulting effective interactions depend on a specific environment, making explicit account of molecular polarizability particularly important in solutions with pronounced anisotropic perturbations, including solid/liquid interfaces and external fields. Our work concerns polarizability effects in nanoscale confinements under electric field, open to an unperturbed bulk environment. We model aqueous molecules and ions in hydrophobic pores using the Gaussian-charge-on-spring BK3-AH representation. This involves nontrivial methodology devel- opments in expanded ensemble Monte Carlo simulations for open systems with long-ranged multibody interactions and necessitates further improvements …
Radical Chemistry In A Femtosecond Laser Plasma: Photochemical Reduction Of Ag+ In Liquid Ammonia Solution, Victoria K. Meader, Mallory G. John, Laysa M. Frias Batista, Syeda Ahsan, Katharine M. Tibbetts
Radical Chemistry In A Femtosecond Laser Plasma: Photochemical Reduction Of Ag+ In Liquid Ammonia Solution, Victoria K. Meader, Mallory G. John, Laysa M. Frias Batista, Syeda Ahsan, Katharine M. Tibbetts
Chemistry Publications
Plasmas with dense concentrations of reactive species such as hydrated electrons and hydroxyl radicals are generated from focusing intense femtosecond laser pulses into aqueous media. These radical species can reduce metal ions such as Au3+ to form metal nanoparticles (NPs). However, the formation of H2O2 by the recombination of hydroxyl radicals inhibits the reduction of Ag+ through back-oxidation. This work has explored the control of hydroxyl radical chemistry in a femtosecond laser-generated plasma through the addition of liquid ammonia. The irradiation of liquid ammonia solutions resulted in a reaction between NH3 and OH·, forming peroxynitrite and ONOO−, and significantly reducing …
Electrokinetic Flow Of Aqueous Electrolyte In Amorphous Silica Nanotubes, Chris D. Daub, Natalie Cann, D. Bratko, Alenka Luzar
Electrokinetic Flow Of Aqueous Electrolyte In Amorphous Silica Nanotubes, Chris D. Daub, Natalie Cann, D. Bratko, Alenka Luzar
Chemistry Publications
We study the pressure-driven flow of aqueous NaCl in amorphous silica nanotubes using nonequilibrium molecular dynamics simulations featuring both polarizable and non-polarizable molecular models. Different pressures, electrolyte concentrations and pore sizes are examined. Our results indicate a flow that deviates considerably from the predictions of Poiseuille fluid mechanics. Due to preferential adsorption of the different ionic species by surface SiO! or SiOH groups, we find that a significant electric current is generated, but with opposite polarities using polarizable vs. fixed charge models for water and ions, emphasizing the need for careful parameterization in such complex systems. We also examine the …
Curvature Dependence Of The Effect Of Ionic Functionalization On The Attraction Among Nanoparticles In Dispersion, B. Shadrack Jabes, D. Bratko, Alenka Luzar
Curvature Dependence Of The Effect Of Ionic Functionalization On The Attraction Among Nanoparticles In Dispersion, B. Shadrack Jabes, D. Bratko, Alenka Luzar
Chemistry Publications
Solubilization of nanoparticles facilitates nanomaterial processing and enables new applications. An effective method to improve dispersibility in water is provided by ionic functionalization.We explore how the necessary extent of functionalization depends on the particle geometry. Using molecular dynamics/umbrella sampling simulations, we determine the effect of the solute curvature on solventaveraged interactions among ionizing graphitic nanoparticles in aqueous dispersion. We tune the hydrophilicity of molecular-brush coated fullerenes, carbon nanotubes, and graphane platelets by gradually replacing a fraction of the methyl end groups of the alkyl coating by the ionizing –COOK or –NH3Cl groups. To assess the change in nanoparticles’ dispersibility in …
Nucleation And Growth Of Gold Nanoparticles Initiated By Nanosecond And Femtosecond Laser Irradiation Of Aqueous [Aucl4]-, Collin Rodrigues, Julian A. Bobb, Mallory G. John, Sergey Fisenko, M. S. El-Shall, Katharine M. Tibbetts
Nucleation And Growth Of Gold Nanoparticles Initiated By Nanosecond And Femtosecond Laser Irradiation Of Aqueous [Aucl4]-, Collin Rodrigues, Julian A. Bobb, Mallory G. John, Sergey Fisenko, M. S. El-Shall, Katharine M. Tibbetts
Chemistry Publications
Irradiation of aqueous [AuCl4]with 532 nm nanosecond (ns) laser pulses produces monodisperse (PDI = 0.04) 5 nm Au nanoparticles (AuNPs) without any additives or capping agents via a plasmon- enhanced photothermal autocatalytic mechanism. Compared with 800 nm femtosecond (fs) laser pulses, the AuNP growth kinetics under ns laser irradiation follow the same autocatalytic rate law, but with a significantly lower sensitivity to laser pulse energy. The results are explained using a simple model for simulating heat transfer in liquid water and at the interface with AuNPs. While the extent of water superheating with the ns laser is smaller compared to …
Deciphering Of Interactions Between Platinated Dna And Hmgb1 By Hydrogen/Deuterium Exchange Mass Spectrometry, Yuanyuan Wang, Zhifeng Du, Wei Zheng, Kui Wu, Decheng Xu, Qun Luo, Yao Zhao, Juanjuan Han, Yangzhong Liu, Fuyi Wang
Deciphering Of Interactions Between Platinated Dna And Hmgb1 By Hydrogen/Deuterium Exchange Mass Spectrometry, Yuanyuan Wang, Zhifeng Du, Wei Zheng, Kui Wu, Decheng Xu, Qun Luo, Yao Zhao, Juanjuan Han, Yangzhong Liu, Fuyi Wang
Chemistry Publications
A high mobility group box 1 (HMGB1) protein has been reported to recognize both 1,2-intrastrand crosslinked DNA by cisplatin (1,2-cis-Pt-DNA) and monofunctional platinated DNA using trans-[PtCl2(NH3)(thiazole)] (1-trans-PtTz-DNA). However, the molecular basis of recognition between the trans-PtTz-DNA and HMGB1 remains unclear. In the present work, we described a hydrogen/deuterium exchange mass spectrometry (HDX-MS) method in combination with docking simulation to decipher the interactions of platinated DNA with domain A of HMGB1. The global deuterium uptake results indicated that 1-trans-PtTz-DNA bound to HMGB1a slightly tighter than the 1,2-cis-Pt-DNA. The local deuterium uptake …
Highly Porous Photoluminescent Diazaborole-Linked Polymers: Synthesis, Characterization, And Application To Selective Gas Adsorption, Zafer Kahveci, Ali K. Sekizkardes, Ravi K. Arvapally, Logan Wilder, Hani M. El-Kaderi
Highly Porous Photoluminescent Diazaborole-Linked Polymers: Synthesis, Characterization, And Application To Selective Gas Adsorption, Zafer Kahveci, Ali K. Sekizkardes, Ravi K. Arvapally, Logan Wilder, Hani M. El-Kaderi
Chemistry Publications
The formation of boron–nitrogen (B–N) bonds has been widely explored for the synthesis of small molecules, oligomers, or linear polymers; however, its use in constructing porous organic frameworks remains very scarce. In this study, three highly porous diazaborole-linked polymers (DBLPs) have been synthesized by condensation reactions using 2,3,6,7,14,15-hexaaminotriptycene and aryl boronic acids. DBLPs are microporous and exhibit high Brunauer–Emmett–Teller surface area (730–986 m2 g−1) which enable their use in small gas storage and separation. At ambient pressure, the amorphous polymers show high CO2 (DBLP-4: 4.5 mmol g−1 at 273 K) and H2 (DBLP-3: 2.13 wt% at 77 K) uptake while …
Mesopore Etching Under Supercritical Conditions – A Shortcut To Hierarchically Porous Silica Monoliths, Martin Von Der Lehr, Kristof Hormann, Alexandra Höltzel, Lauren S. White, Arved E. Reising, Massimo F. Bertino, Bernd M. Smarsly, Ulrich Tallarek
Mesopore Etching Under Supercritical Conditions – A Shortcut To Hierarchically Porous Silica Monoliths, Martin Von Der Lehr, Kristof Hormann, Alexandra Höltzel, Lauren S. White, Arved E. Reising, Massimo F. Bertino, Bernd M. Smarsly, Ulrich Tallarek
Chemistry Publications
Hierarchically porous silica monoliths are obtained in the two-step Nakanishi process, where formation of a macro microporous silica gel is followed by widening micropores to mesopores through surface etching. The latter step is carried out through hydrothermal treatment of the gel in alkaline solution and necessitates a lengthy solvent exchange of the aqueous pore fluid before the ripened gel can be dried and calcined into a mechanically stable macro mesoporous monolith. We show that using an ethanol water (95.6/4.4, v/v) azeotrope as supercritical fluid for mesopore etching eliminates the solvent exchange, ripening, and drying steps of the classic route and …
Palladium Nanoparticles Supported On Ce-Metal–Organic Framework For Efficient Co Oxidation And Low-Temperature Co2 Capture, Andrew Lin, Amr Awad Ibrahim, Pezhman Arab, Hanii M. El-Kaderi, M. Samy El-Shall
Palladium Nanoparticles Supported On Ce-Metal–Organic Framework For Efficient Co Oxidation And Low-Temperature Co2 Capture, Andrew Lin, Amr Awad Ibrahim, Pezhman Arab, Hanii M. El-Kaderi, M. Samy El-Shall
Chemistry Publications
In this article, we report the lowest-temperature CO oxidation catalyst supported on metal–organic frameworks (MOFs). We have developed a facile, general, and effective approach based on microwave irradiation for the incorporation of Pd nanoparticle catalyst within Ce-MOF. The resulting Pd/Ce-MOF material is a unique catalyst that is capable of CO oxidation at modest temperatures and also of efficient uptake of the product CO2 gas at low temperatures. The observed catalytic activity of this material toward CO oxidation is significantly higher than those of other reported metal nanoparticles supported on MOFs. The high activity of the Pd/Ce-MOF catalyst is due to …
Roles Of Free Electrons And H2o2 In The Optical Breakdown-Induced Photochemical Reduction Of Aqueous [Aucl4]-, Victoria K. Meader, Mallory G. John, Collin Rodrigues, Katharine M. Tibbetts
Roles Of Free Electrons And H2o2 In The Optical Breakdown-Induced Photochemical Reduction Of Aqueous [Aucl4]-, Victoria K. Meader, Mallory G. John, Collin Rodrigues, Katharine M. Tibbetts
Chemistry Publications
Free electrons and H2O2 formed in an optical breakdown plasma are found to directly control the kinetics of [AuCl4]− reduction to form Au nanoparticles (AuNPs) during femtosecond laser-assisted synthesis of AuNPs. The formation rates of both free electrons and H2O2 strongly depend on the energy and duration of the 800 nm laser pulses over the ranges of 10−2400 μJ and 30−1500 fs. By monitoring the conversion of [AuCl4]− to AuNPs using in situ UV−vis spectroscopy during laser irradiation, the first- and second-order rate constants in the autocatalytic rate law, k1 and k2, were extracted and compared to the computed free …
Bolstering Cholesteryl Ester Hydrolysis In Liver: A Hepatocyte-Targeting Gene Delivery Strategy For Potential Alleviation Of Atherosclerosis, Hongliang He, Michael G. Lancina Iii, Jing Wang, William J. Korzun, Hu Yang, Shobha Ghosh
Bolstering Cholesteryl Ester Hydrolysis In Liver: A Hepatocyte-Targeting Gene Delivery Strategy For Potential Alleviation Of Atherosclerosis, Hongliang He, Michael G. Lancina Iii, Jing Wang, William J. Korzun, Hu Yang, Shobha Ghosh
Chemistry Publications
Current atherosclerosis treatment strategies primarily focus on limiting further cholesteryl esters (CE) accumulation by reducing endogenous synthesis of cholesterol in the liver. No therapy is currently available to enhance the removal of CE, a crucial step to reduce the burden of the existing disease. Given the central role of hepatic cholesteryl ester hydrolase (CEH) in the intrahepatic hydrolysis of CE and subsequent removal of the resulting free cholesterol (FC), in this work, we applied galactosefunctionalized polyamidoamine (PAMAM) dendrimer generation 5 (Gal-G5) for hepatocyte-specific delivery of CEH expression vector. The data presented herein show the increased specific uptake of Gal-G5/CEH expression …
Binding Mode Analyses Of Nap Derivatives As Mu Opioid Receptor Selective Ligands Through Docking Studies And Molecular Dynamics Simulation, Huiqun Wang, Saheem A. Zaidi, Yan Zhang
Binding Mode Analyses Of Nap Derivatives As Mu Opioid Receptor Selective Ligands Through Docking Studies And Molecular Dynamics Simulation, Huiqun Wang, Saheem A. Zaidi, Yan Zhang
Chemistry Publications
Mu opioid receptor selective antagonists are highly desirable because of their utility as pharmacological probes for receptor characterization and functional studies. Furthermore, the mu opioid receptors act as an important target in drug abuse and addiction treatment. Previously, we reported NAP as a novel lead compound with high selectivity and affinity towards the mu opioid receptor. Based on NAP, we have synthesized its derivatives and further characterized their binding affinities and selectivity towards the receptor. NMP and NGP were identified as the two most selective MOR ligands among NAP derivatives. In the present study, molecular modeling methods were applied to …
Microbial-Physical Synthesis Of Fe And Fe3o4 Magnetic Nanoparticles Using Aspergillus Niger Yesm1 And Supercritical Condition Of Ethanol, Mai Abdeen, Soraya Sabry, Hanan Ghozlan, Ahmed A. El-Gendy, Everett E. Carpenter
Microbial-Physical Synthesis Of Fe And Fe3o4 Magnetic Nanoparticles Using Aspergillus Niger Yesm1 And Supercritical Condition Of Ethanol, Mai Abdeen, Soraya Sabry, Hanan Ghozlan, Ahmed A. El-Gendy, Everett E. Carpenter
Chemistry Publications
Magnetic Fe and Fe3O4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300∘ C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit …