jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: James K. Utterback | Alex J. King | Livia Belman-Wells | David M. Larson | Leo M. Hamerlynck | Adam Z. Weber | Naomi S. Ginsberg
Source: arXiv (Cornell University) (preprint, 2023-01-18)
Field: Chemistry — Electrochemistry

Operando Label-free Optical Imaging of Solution-Phase Ion Transport and Electrochemistry Ion transport is a fundamental process in many physical, chemical, and biological phenomena, and especially in electrochemical energy conversion and storage. Despite its immense importance, demonstrations of label-free, spatially and temporally resolved ion imaging in the solution phase under operando conditions are not widespread. Here we spatiotemporally map ion concentration gradient evolution in solution and yield ion transport parameters by refining interferometric reflection microscopy, obviating the need for absorptive or fluorescent labels. As an example, we use an electrochemical cell with planar electrodes to drive concentration gradients in a ferricyanide-based aqueous redox electrolyte, and we observe the lateral spatiotemporal evolution of ions via concentration-dependent changes to the refractive index. Analysis of an evolving spatiotemporal ion distribution directly yields the diffusivity of the redox-active species. The simplicity of this approach makes it amenable to probing local ion transport behavior in a wide range of electrochemical, bioelectronic, and electrophysiological systems. Ferricyanide ; Ion ; Electrochemistry ; Redox ; Phase (matter) ; Materials science ; Chemistry ; Aqueous solution ; Chemical physics ; Electrode ; Nanotechnology ; Analytical Chemistry (journal) ; Inorganic chemistry ; Chromatography Electrochemical Analysis and Applications ; Force Microscopy Techniques and Applications ; Analytical Chemistry and Sensors
Authors: D. Paul Mallory | Abegel Freedman | Megan J. Kaliszewski | Gladys Rocío Montenegro-Galindo | Coleen Pugh | Adam W. Smith
Source: Biomacromolecules (article, 2023-05-24)
Field: Chemistry — Organic Chemistry

Direct Quantification of Serum Protein Interactions with PEGylated Micelle Nanocarriers A large repertoire of nanocarrier (NC) technologies exists, each with highly specified advantages in terms of targetability, stability, and immunological inertness. The characterization of such NC properties within physiological conditions is essential for the development of optimized drug delivery systems. One method that is well established for reducing premature elimination by avoiding protein adsorption on NCs is surface functionalization with poly(ethylene glycol) (PEG), aptly called PEGylation. However, recent studies revealed that some PEGylated NCs have a delayed immune response, indicating the occurrence of protein-NC interactions. Obvious protein-NC interactions, especially in micellar systems, may have been overlooked as many early studies relied on techniques less sensitive to molecular level interactions. More sensitive techniques have been developed, but a major challenge is the direct measurement of interactions, which must be done in situ, as micelle assemblies are dynamic. Here, we report the use of pulsed-interleaved excitation fluorescence cross-correlation spectroscopy (PIE-FCCS) to interrogate the interactions between two PEG-based micelle models and serum albumin protein to compare protein adsorption differences based on linear or cyclic PEG architectures. First, by measuring micelle diffusion in isolated and mixed solutions, we confirmed the thermal stability of diblock and triblock copolymer micelle assemblies. Further, we measured the co-diffusion of micelles and serum proteins, the magnitudes of which increased with concentration and continued incubation. The results demonstrate that PIE-FCCS is capable of measuring direct interactions between fluorescently labeled NC and serum proteins, even at concentrations 500 times lower than those observed physiologically. This capability showcases the potential utility of PIE-FCCS in the characterization of drug delivery systems in biomimetic conditions. Nanocarriers ; Micelle ; PEGylation ; Chemistry ; Biophysics ; PEG ratio ; Protein adsorption ; Ethylene glycol ; Bovine serum albumin ; Fluorescence correlation spectroscopy ; Drug delivery ; Protein–protein interaction ; Critical micelle concentration ; Adsorption ; Chromatography ; Polyethylene glycol ; Organic chemistry ; Biochemistry ; Aqueous solution ; Molecule Surfactants and Colloidal Systems ; Nanoparticle-Based Drug Delivery ; Protein Interaction Studies and Fluorescence Analysis
Authors: Jiajie Guo | Shinya E. Chen | Rajiv Giridharagopa | Connor G. Bischak | Jonathan W. Onorato | Kangrong Yan | Ziqiu Shen | Chang‐Zhi Li | Christine K. Luscombe | David S. Ginger
Source: arXiv (Cornell University) (preprint, 2023-05-02)
Field: Materials Science — Polymers and Plastics

Why accumulation mode organic electrochemical transistors turn off much faster than they turn on Understanding the factors underpinning device switching times is crucial for the implementation of organic electrochemical transistors (OECTs) in neuromorphic computing and real-time sensing applications. Existing models of device operation cannot explain the experimental observations that turn-off times are generally much faster than turn-on times in accumulation mode OECTs. Through operando optical microscopy, we image the local doping level of the transistor channel and show that device turn-on occurs in two stages, while turn-off occurs in one stage. We attribute the faster turn-off to a combination of engineering as well as physical and chemical factors including channel geometry, differences in doping and dedoping kinetics, and the physical phenomena of carrier density-dependent mobility. We show that ion transport is limiting the device operation speed in our model devices. Our study provides insights into the kinetics of OECTs and guidelines for engineering faster OECTs. Neuromorphic engineering ; Transistor ; Turn (biochemistry) ; Limiting ; Underpinning ; Materials science ; Channel (broadcasting) ; Nanotechnology ; Electrode ; Doping ; Optoelectronics ; Electrochemistry ; Kinetics ; Computer science ; Chemistry ; Voltage ; Electrical engineering ; Physics ; Artificial neural network ; Engineering ; Mechanical engineering ; Artificial intelligence ; Telecommunications Conducting polymers and applications ; Advanced Memory and Neural Computing ; Organic Electronics and Photovoltaics
Authors: Laura Andreozzi | Elisa Martinelli
Source: Preprints.org (preprint, 2023-09-21)
Field: Chemistry — Organic Chemistry

An ESR Study Comparing Nanometer-Nanosecond Dynamics in Diblock Copolymers and Their PMMA Binary Blends Block copolymers are a class of materials particularly interesting for their ability to self-assemble into ordered structures. In this context, the coupling between environment and dynamics is particularly relevant, given that movements at the molecular level influence various properties of macromolecules. Mixing the polymer with a second macromolecule appears to be an easy way to study these relationships. In this work, we studied a system based on two diblock copolymers of methyl methacrylate as first block and 3-methyl-4-[6-(methylacryloyloxy)-hexyloxy]-4’-pentyloxy azobenzene as second block and their blends with PMMA. The relaxational properties of these systems were investigated by electron spin resonance (ESR) spectroscopy sensitive to nanometric length-scales. The results of the study on the blends were related to the dynamic behavior of the copolymer. The study evidenced the presence of fast and slow molecular sites for the molecular reorientation at nanoscale, modulated by the ability of block copolymer to form supramolecular structures. For blends, the heterogeneities at nanoscale are still detected. However it was found that the presence of the PMMA as the major component of the blends modified their dynamic behaviour. Copolymer ; Materials science ; Context (archaeology) ; Polymer ; Supramolecular chemistry ; Nanosecond ; Micelle ; Molecular dynamics ; Chemical physics ; Polymer blend ; Nanoscopic scale ; Macromolecule ; Methyl methacrylate ; Nanometre ; Polymer chemistry ; Chemical engineering ; Nanotechnology ; Molecule ; Chemistry ; Composite material ; Physical chemistry ; Computational chemistry ; Optics ; Organic chemistry ; Physics Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems ; Electrostatics and Colloid Interactions
Authors: Jiaojiao Yuan | Su Tuo | Yangyang Liu | Jing He | Shao‐Hwa Hu | Junling Tu
Source: JOURNAL OF RENEWABLE MATERIALS (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Investigation of the Thermal Decomposition Behavior of Oleuropein with Many Pharmacological Activities from Olive by Thermogravimetry Due to the existence of poly-hydroxyl structures, the temperature may have an effect on the thermal stability of oleuropein for its applications. In the current study, the thermal decomposition process and kinetics behavior of oleuropein from the olive resource were researched by thermogravimetric theoretical analysis methods and non-isothermal kinetics simulation. The results of thermogravimetry analysis showed the whole thermal decomposition process of oleuropein involved two stages, with 21.22% of residue. It was also revealed that high heating rates of more than 20 K min<sup>−1</sup> led to significant thermal hysteresis and inhibited the whole thermal decomposition behavior of oleuropein. Moreover, an investigation of the thermal decomposition kinetics indicated that the non-isothermal decomposition behavior followed a D3 model during the first stage (three-dimensional diffusion, Jander equation) and a D1 model in the second stage (one-dimensional diffusion). For the first and second thermal decomposition stages, the Kissinger, Friedman, Flynn-Wall-Ozawa, and Coats–Redfern four methods were applied to determine the activation energy (<i>E</i> = 143.72 and 247.01 kJ mol<sup>−1</sup>) and Arrhenius preexponential factor (ln <i>A</i> = 26.34 and 42.45 min<sup>−1</sup>), respectively. Therefore, the study will provide good theoretical guidance for thermal stability and thermal transformation application of oleuropein. It will be suitable for low-temperature applications in the cosmetic, food supplement and pharmaceutical industries. Oleuropein ; Thermogravimetry ; Thermal decomposition ; Isothermal process ; Arrhenius equation ; Thermal stability ; Thermogravimetric analysis ; Decomposition ; Activation energy ; Kinetics ; Chemistry ; Diffusion ; Thermal analysis ; Pyrolysis ; Materials science ; Chemical process of decomposition ; Thermodynamics ; Chemical engineering ; Thermal ; Physical chemistry ; Organic chemistry ; Inorganic chemistry Thermal and Kinetic Analysis ; Bee Products Chemical Analysis ; Chemical Thermodynamics and Molecular Structure
Authors: Talisi E. Meyer | Kevin Zhijian Jiang | Ching Chun Peng | Quynh P. Sam | Minsoo Kang | Reilly P. Lynch | Jonathan L. Rowell | Judy Cha | Richard D. Robinson
Source: ACS Materials Au (article, 2023-07-10)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Scalable Route to Colloidal Ni<sub><i>x</i></sub>Co<sub>3–<i>x</i></sub>S<sub>4</sub> Nanoparticles with Low Dispersity Using Amino Acids The thiospinel group of nickel cobalt sulfides (Ni<sub><i>x</i></sub>Co<sub>3-<i>x</i></sub>S<sub>4</sub>) are promising materials for energy applications such as supercapacitors, fuel cells, and solar cells. Solution-processible nanoparticles of Ni<sub><i>x</i></sub>Co<sub>3-<i>x</i></sub>S<sub>4</sub> have advantages of low cost and fabrication of high-performance energy devices due to their high surface-to-volume ratio, which increases the electrochemically active surface area and shortens the ionic diffusion path. The current approaches to synthesize Ni<sub><i>x</i></sub>Co<sub>3-<i>x</i></sub>S<sub>4</sub> nanoparticles are often based on hydrothermal or solvothermal methods that are difficult to scale up safely and efficiently and that preclude monitoring the reaction through aliquots, making optimization of size and dispersity challenging, typically resulting in aggregated nanoparticles with polydisperse sizes. In this work, we report a scalable "heat-up" method to colloidally synthesize Ni<sub><i>x</i></sub>Co<sub>3-<i>x</i></sub>S<sub>4</sub> nanoparticles that are smaller than 15 nm in diameter with less than 15% in size dispersion, using two inexpensive, earth-abundant sulfur sources. Our method provides a reliable synthetic pathway to produce phase-pure, low-dispersity, gram-scale nanoparticles of ternary metal sulfides. This method enhances the current capabilities of Ni<sub><i>x</i></sub>Co<sub>3-<i>x</i></sub>S<sub>4</sub> nanoparticles to meet the performance demands to improve renewable energy technologies. Dispersity ; Nanoparticle ; Materials science ; Nanotechnology ; Chemical engineering ; Ternary operation ; Computer science Supercapacitor Materials and Fabrication ; Advanced battery technologies research ; Electrocatalysts for Energy Conversion
Authors: Sabarinathan P Subramaniyan | Pavana Prabhakar
Source: arXiv (Cornell University) (preprint, 2023-07-25)
Field: Materials Science — Polymers and Plastics

Moisture-Driven Degradation Mechanisms in the Viscoelastic Properties of TPU-Based Syntactic Foams Syntactic foams have found widespread usage in various applications including, marine, aerospace, automotive, pipe insulation, electrical cable sheathing, and shoe insoles. However, syntactic foams are often exposed to moisture when used in these applications that potentially alter their viscoelastic properties, which influences their long-term durability. Despite their significance, previous research has mainly focused on experimental studies concerning mechanical property changes resulting from filler loading and different matrix materials, overlooking the fundamental mechanisms resulting from moisture exposure. The current paper aims to bridge this gap in knowledge by elucidating the impact of long-term moisture exposure on TPU and TPU-based syntactic foam through multi-scale materials characterization approaches. Here, we choose a flexible syntactic foam manufactured using thermoplastic polyurethane elastomer (TPU) reinforced with glass microballoons (GMB) through selective laser sintering. Specifically, the research investigates the influence of moisture exposure time and the volume fraction of GMB on chemical and microphase morphological changes, along with their associated mechanisms. The study further examines how these microphase morphological changes manifest in viscoelastic properties. Syntactic foam ; Materials science ; Composite material ; Thermoplastic polyurethane ; Moisture ; Viscoelasticity ; Glass microsphere ; Elastomer ; Microsphere ; Chemical engineering Polymer composites and self-healing ; Cellular and Composite Structures ; Advanced Sensor and Energy Harvesting Materials
Authors: Sarah Hailan | Patrik Sobolčiak | Peter Kasák | Anton Popelka | Yongfeng Tong | Samer Adham | Igor Krupa
Source: Environmental Technology & Innovation (article, 2023-05-12)
Field: Materials Science — Materials Chemistry

Purification of emulsified oily polluted waters with modified melamine foams Oil and gas industry operations produce tremendous amounts of wastewater (produced water; PW). Tertiary treatment of the PW in the final treatment stage is challenging due to the presence of colloids with sizes < 500 nm and a low concentration target for the effluent of <10 mg/L. This study was focused on the purification of colloidal PW with modified melamine foams (MFs) and ferric chloride. The modified MFs exhibited superhydrophobic and superoleophilic character due to increasing roughness and complexation of Fe3＋ ions within the MF structure. The modified MF showed separation efficiencies up to 86 ± 3% for emulsions containing 120 ppm carbon. The Fe3＋ cations changed the hydrophilicities of the foams and made them highly hydrophobic, and they also contributed significantly to the adsorption of negatively charged species, such as crude oil droplets modified with an anionic surfactant (sodium dodecyl sulfate). The demulsification mechanism involved multiple diffusion processes run over different time scales, including diffusion of an emulsion into the foam and diffusion of the oil droplets within the foam, combined with parallel adsorption of the oil droplets onto the solid skeleton of the foam. The adsorption capacity of the MFs increased linearly with increasing initial concentration of crude oil content in the PW. The MFs were reusable for six consecutive cycles. Adsorption ; Melamine ; Oil droplet ; Emulsion ; Chemical engineering ; Pulmonary surfactant ; Colloid ; Diffusion ; Ferric ; Chloride ; Produced water ; Chemistry ; Materials science ; Chromatography ; Inorganic chemistry ; Organic chemistry ; Waste management Pickering emulsions and particle stabilization ; Electrohydrodynamics and Fluid Dynamics ; Enhanced Oil Recovery Techniques
Authors: Xinzhu Wang | Zhenhuan Wei | Po Hu | Weibo Xia | Zhi‐Xin Liao | Israa Assani | Guangming Yang | Yang Pan
Source: Molecules (article, 2023-06-29)
Field: Chemistry — Analytical Chemistry

Optimization of Neferine Purification Based on Response Surface Methodology and Its Anti-Metastasis Mechanism on HepG2 Cells Liver cancer continues to be a focus of scientific research due to its low five-year survival rate. One of its main core issues is the high metastasis of cells, for which there is no effective treatment. Neferine was originally isolated from <i>Plumula nelumbinis</i> and demonstrated to have a good antitumor effect. In order to extract high-purity Neferine in a more efficient and environmentally friendly manner, response surface methodology (RSM) was used to optimize the isolation and purification procedures in this study. The extract conditions of a 7:3 ratio for the eluent of dichloromethane: methanol, 1:60 for the mass ratio of the extract amount: silica gel, and 3 mL/min of the elution flow rate were shown to be the optimal conditions. These conditions resulted in the highest yield of 6.13 mg per 66.60 mg of starting material, with productivity of 8.76% and purity of 87.04%. Compared with the previous methods, this method can prepare Neferine in large quantities more quickly. We subsequently evaluated the antitumor activity of the purified Neferine against HepG2 hepatic cancer cells. The purified Neferine was found to inhibit the proliferation of HepG2 cells through the CCK-8 assay, with an <i>IC</i><sub>50</sub> of 33.80 μM in 24 h, 29.47 μM in 48 h, 24.35 μM in 72 h and 2.78 μM in 96 h of treatment. Neferine at a concentration of 3 μM could significantly inhibit the migration and invasion abilities of the HepG2 cells in vitro. We also explored the mechanism of action of Neferine via Western blot. We showed that Neferine could reduce RhoA expression by effectively inhibiting the phosphorylation of MYPT1, thereby effectively exerting anti-metastasis activity against HepG2 cells. Thus, we have optimized the isolation procedures for highly pure Neferine by response surface methodology (RSM) in this study, and purified Neferine is shown to play an essential role in the anti-metastasis process of liver cancer cells. The Neferine purification procedure may make a wide contribution to the follow-up development of other anti-metastasis lead compounds. Dichloromethane ; Chemistry ; In vitro ; Elution ; IC50 ; Chromatography ; Column chromatography ; Methanol ; Metastasis ; Biochemistry ; Biology ; Cancer ; Organic chemistry Chromatography in Natural Products ; Phytochemical Studies and Bioactivities ; Natural product bioactivities and synthesis
Authors: Signe Kyrkjebø | Andrew Cassidy | Sam Lambrick | A. P. Jardine | Bodil Holst | Liv Hornekær
Source: Frontiers in Chemistry (article, 2023-10-06)
Field: Materials Science — Materials Chemistry

3He spin-echo scattering indicates hindered diffusion of isolated water molecules on graphene-covered Ir(111) The dynamics of water diffusion on carbon surfaces are of interest in fields as diverse as furthering the use of graphene as an industrial-coating technology and understanding the catalytic role of carbon-based dust grains in the interstellar medium. The early stages of water-ice growth and the mobility of water adsorbates are inherently dependent on the microscopic mechanisms that facilitate water diffusion. Here, we use <sup>3</sup>He spin-echo quasi-inelastic scattering to probe the microscopic mechanisms responsible for the diffusion of isolated water molecules on graphene-covered and bare Ir(111). The scattering of He atoms provides a non-invasive and highly surface-sensitive means to measure the rate at which absorbates move around on a substrate at very low coverage. Our results provide an approximate upper limit on the diffusion coefficient for water molecules on GrIr(111) of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo><</mml:mo><mml:msup><mml:mrow><mml:mn>10</mml:mn></mml:mrow><mml:mrow><mml:mo>-</mml:mo><mml:mn>12</mml:mn></mml:mrow></mml:msup></mml:math> m<sup>2</sup>/s, an order of magnitude lower than the coefficient that describes the diffusion of water molecules on the bare Ir(111) surface. We attribute the hindered diffusion of water molecules on the GrIr(111) surface to water trapping at specific areas of the corrugated moiré superstructure. Lower mobility of water molecules on a surface is expected to lead to a lower ice nucleation rate and may enhance the macroscopic anti-icing properties of a surface. Diffusion ; Molecule ; Materials science ; Nucleation ; Graphene ; Chemical physics ; Scattering ; Analytical Chemistry (journal) ; Chemistry ; Nanotechnology ; Physics ; Thermodynamics ; Optics ; Organic chemistry Graphene research and applications ; Physics of Superconductivity and Magnetism ; Advanced Condensed Matter Physics
Authors: Yogashree Bharath | Arvind Rajendran
Source: ChemRxiv (preprint, 2023-07-07)
Field: Chemistry — Inorganic Chemistry

Evaluation of a tetramine-appended MOF for post-combustion CO2 capture from natural gas combined cycle flue gas by steam-assisted temperature swing adsorption A novel tetraamine-appended metal-organic framework (MOF), exhibiting double- stepped isotherm was explored in a 3-step steam-assisted temperature swing adsorption process (SA-TSA) for CO2 removal from dry flue gas emitted from natural gas-fired power plants (NGCC). The reported material exhibited properties highly suited for CO2 capture from dilute sources. Extensive numerical simulations were performed to comprehend the impact of isotherm shape, heat transfer coefficient, feed temperature and heat capacity of solid on adsorption and desorption dynamics in a fixed bed. A multi-objective optimization was performed to identify operating conditions that achieve low steam consumption and high productivity while maintaining high purity (>=95%) and high recovery (>=90%). It was found that high purity and high recovery are obtained only when the process is isothermal. Thermal fronts propagating through the column impact the process performance. We show that the process cannot achieve recovery targets, i.e., >=90%, unless heat is removed from the system rapidly. The lowest achievable specific steam consumption is ≈45 kg steam/kg CO2 cap and highest achievable productivity is ≈ 0.1 mol CO2/m3 ads/s in an isothermal scenario. Flue gas ; Natural gas ; Isothermal process ; Chemistry ; Combustion ; Heat recovery steam generator ; Desorption ; Adsorption ; Thermodynamics ; Process engineering ; Chemical engineering ; Nuclear engineering ; Waste management ; Thermal power station ; Organic chemistry ; Engineering Metal-Organic Frameworks: Synthesis and Applications ; Carbon Dioxide Capture Technologies ; Membrane Separation and Gas Transport