jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Allison L. Chau | Chelsea E. R. Edwards | Matthew E. Helgeson | Angela A. Pitenis
Source: ACS Applied Materials & Interfaces (article, 2023-08-31)
Field: Materials Science — Surfaces, Coatings and Films

Designing Superlubricious Hydrogels from Spontaneous Peroxidation Gradients Hydrogels are hydrated three-dimensional networks of hydrophilic polymers that are commonly used in the biomedical industry due to their mechanical and structural tunability, biocompatibility, and similar water content to biological tissues. The surface structure of hydrogels polymerized through free-radical polymerization can be modified by controlling environmental oxygen concentrations, leading to the formation of a polymer concentration gradient. In this work, 17.5 wt % polyacrylamide hydrogels are polymerized in low (0.01 mol % O<sub>2</sub>) and high (20 mol % O<sub>2</sub>) oxygen environments, and their mechanical and tribological properties are characterized through microindentation, nanoindentation, and tribological sliding experiments. Without significantly reducing the elastic modulus of the hydrogel (<i>E*</i> ≈ 200 kPa), we demonstrate an order of magnitude reduction in friction coefficient (from μ = 0.021 ± 0.006 to μ = 0.002 ± 0.001) by adjusting polymerization conditions (e.g., oxygen concentration). A quantitative analytical model based on polyacrylamide chemistry and kinetics was developed to estimate the thickness and structure of the monomer conversion gradient, termed the "surface gel layer". We find that polymerizing hydrogels at high oxygen concentrations leads to the formation of a preswollen surface gel layer that is approximately five times thicker (<i>t</i> ≈ 50 μm) and four times less concentrated (≈ 6% monomer conversion) at the surface prior to swelling compared to low oxygen environments (<i>t</i> ≈ 10 μm, ≈ 20% monomer conversion). Our model could be readily modified to predict the preswollen concentration profile of the polyacrylamide gel surface layer for any reaction conditions─monomer and initiator concentration, oxygen concentration, reaction time, and reaction media depth─or used to select conditions that correspond to a certain desired surface gel layer profile. Self-healing hydrogels ; Materials science ; Polyacrylamide ; Polymerization ; Monomer ; Polymer ; Chemical engineering ; Biocompatibility ; Oxygen ; Limiting oxygen concentration ; Polymer chemistry ; Composite material ; Chemistry ; Organic chemistry Polymer Surface Interaction Studies ; Hydrogels: synthesis, properties, applications ; Electrospun Nanofibers in Biomedical Applications
Authors: Yin Wang | Randy Nziengui Raby | Yuankai Li | Zuojun Li | Mengqing Sun | Zhi Huang
Source: Bioengineering (article, 2023-01-18)
Field: Materials Science — Biomaterials

An Alternating Magnetic Field-Controlled Drug Delivery System Based on 4,4′-Azobis (4-cyanovaleric Acid)-Functioned Fe3O4@Chitosan Nanoparticles Herein, we designed chitosan-coated Fe<sub>3</sub>O<sub>4</sub> nanocomposites for the control release of drugs by an alternating magnetic field (AMF). The chitosan-coated Fe<sub>3</sub>O<sub>4</sub> nanoparticles (Fe<sub>3</sub>O<sub>4</sub>@CS) were prepared by a alkaline co-precipitation method, and then, the model drug toluidine blue (TB) was covalently grafted onto the surface of the nanocomposite by a two-step amide reaction with the thermosensitive molecule 4,4'-azobis (4-cyanovaleric acid) (ACVA) as the linker group. The prepared nanocomposites were superparamagnetic and showed high magnetization saturation (about 54.0 emu g<sup>-1</sup>). In vitro hydrothermal release studies showed that most parts of the TB would be effectively enclosed within the nanocarriers at lower ambient temperatures (23 or 37 °C) due to the molecular bonding of ACVA. The results of kinetic fitting of hydrothermal release data showed that TB released from nanoparticles followed first-order kinetics (R<sup>2</sup> > 0.99) and the Korsemeyer-Peppas model (R<sup>2</sup> > 0.99, n < 0.5). Most importantly, a single magnetron release experiment demonstrated an approximately linear relationship between the cumulative release of the drug and the duration of action of AMF (R<sup>2</sup> = 0.9712). Moreover, the increase in the cumulative release of the drug can be controlled by controlling the switch of the AMF generation device. Therefore, the ACVA-modified Fe<sub>3</sub>O<sub>4</sub>@CS nanocarrier designed in this study is a promising model for drug delivery that enables the control of drug release dose by AMF. Nanocarriers ; Chitosan ; Nanocomposite ; Superparamagnetism ; Drug delivery ; Nanoparticle ; Materials science ; Chemical engineering ; Nuclear chemistry ; Kinetics ; Chemistry ; Nanotechnology ; Organic chemistry ; Magnetization ; Magnetic field Nanoparticle-Based Drug Delivery ; Characterization and Applications of Magnetic Nanoparticles ; Hydrogels: synthesis, properties, applications
Authors: Margarita Baitimirova | Raitis Sondors | Lasma Bugovecka | Artis Kons | Lı̅ga Avotiņa | Jana Andžāne
Source: Scientific Reports (article, 2023-11-29)
Field: Materials Science — Materials Chemistry

Enhanced thermoelectric properties of self-assembling ZnO nanowire networks encapsulated in nonconductive polymers The near-room temperature thermoelectric properties of self-assembling ZnO nanowire networks before and after encapsulation in nonconductive polymers are studied. ZnO nanowire networks were synthesized via a two-step fabrication technique involving the deposition of metallic Zn networks by thermal evaporation, followed by thermal oxidation. Synthesized ZnO nanowire networks were encapsulated in polyvinyl alcohol (PVA) or commercially available epoxy adhesive. Comparison of electrical resistance and Seebeck coefficient of the ZnO nanowire networks before and after encapsulation showed a significant increase in the network's electrical conductivity accompanied by the increase of its Seebeck coefficient after the encapsulation. The thermoelectric power factor (PF) of the encapsulated ZnO nanowire networks exceeded the PF of bare ZnO networks by ~ 5 and ~ 185 times for PVA- and epoxy-encapsulated samples, respectively, reaching 0.85 μW m<sup>-1</sup> K<sup>-2</sup> and ZT ~ 3·10<sup>-6</sup> at room temperature, which significantly exceeded the PF and ZT values for state-of-the-art non-conductive polymers based thermoelectric flexible films. Mechanisms underlying the improvement of the thermoelectrical properties of ZnO nanowire networks due to their encapsulation are discussed. In addition, encapsulated ZnO nanowire networks showed excellent stability during 100 repetitive bending cycles down to a 5 mm radius, which makes them perspective for the application in flexible thermoelectrics. Materials science ; Nanowire ; Thermoelectric effect ; Seebeck coefficient ; Polyvinyl alcohol ; Thermoelectric materials ; Polymer ; Nanotechnology ; Electrical resistivity and conductivity ; Thermal conductivity ; Composite material ; Chemical engineering Advanced Thermoelectric Materials and Devices ; Advanced Sensor and Energy Harvesting Materials ; ZnO doping and properties
Authors: Irene Sierra | J.L. Ayastuy | M.A. Gutiérrez–Ortiz | Unai Iriarte‐Velasco
Source: Journal of Analytical and Applied Pyrolysis (article, 2023-04-10)
Field: Materials Science — Materials Chemistry

A study on the impact of the reaction mechanism of the thermochemical activation of bone char (by pyrolysis and carbonization) Porous materials based on bioapatite were prepared through the thermochemical activation of pork bone char, using different reagents (H2SO4 and K2CO3), heating atmosphere (inert and oxidizing) and activation temperature. Thermogravimetric analysis coupled to mass spectrometry was used to propose a detailed activation mechanism. Regarding the effect of each reagent on the activation, whereas that of H2SO4 is attributed to specific reactions, the effect of K2CO3 is ascribed to (i) the role of K+ as a catalyst for reactions such as the gasification of carbon and (ii) the incorporation of carbonates, involved in several reactions. The best textural properties are obtained in an oxidizing atmosphere at 350 ºC. The beneficial effect of the combustion reactions at an intermediate temperature results in a cost-effective preparation protocol. H2SO4 leads to a selective development of microporosity. The oxidizing atmosphere is involved in the generation of OH- functional groups. These results demonstrate the feasibility of configuring activation protocols to tailor the physicochemical properties of biapatite-based materials, for use in specific fields. Oxidizing agent ; Char ; Carbonization ; Pyrolysis ; Chemistry ; Reagent ; Inert gas ; Thermogravimetric analysis ; Chemical engineering ; Combustion ; Catalysis ; Reaction mechanism ; Inert ; Carbon fibers ; Activation energy ; Organic chemistry ; Materials science ; Adsorption ; Composite material Thermal and Kinetic Analysis ; Bone Tissue Engineering Materials ; Catalysis and Hydrodesulfurization Studies
Authors: Changhui Niu | Qing Zhang | Laifei Cheng | Fang Ye | Litong Zhang | Min Huang | Tao Yang
Source: Journal of Advanced Ceramics (article, 2023-11-27)
Field: Materials Science — Ceramics and Composites

Enhanced thermal conductivity and mechanical properties of 2D C <sub>f</sub>/SiC composites modified by <i>in-situ</i> grown carbon nanotubes In this work, the effects of carbon nanotubes (CNTs) on the microstructure evolution, thermal conductivity, and mechanical properties of C<sub>f</sub>/SiC composites during chemical vapor infiltration (CVI) densification were investigated in detail. Compared with composites without CNTs, the thermal conductivity, flexural strength, flexural modulus, fracture toughness, interfacial shear strength and proportional limit stress of specimens with 4.94 wt.% of CNTs were improved by 117%, 21.8%, 67.4%, 10.3%, 36.4% and 71.1%, respectively. This improvement was attributed to the role of CNTs in the division of inter-layer pores, which provided abundant vapor growth sites for the ceramic matrix and promoted densification of the whole composite. In addition, the high thermal conductivity network formed by the overlap of CNTs and the rivet strengthening effect of CNTs were beneficial for synergistic improvement of thermal conductivity and mechanical properties of the composites. Therefore, this study has practical significance for the development of thermal protection composite components with enhanced thermal conductivity and mechanical characteristics. Materials science ; Composite material ; Thermal conductivity ; Carbon nanotube ; Chemical vapor infiltration ; Flexural strength ; Composite number ; Fracture toughness ; Microstructure ; Ceramic ; Ceramic matrix composite ; Toughness Advanced ceramic materials synthesis ; Thermal properties of materials ; Aluminum Alloys Composites Properties
Authors: Yoshinori Morita | Yuko Saito | Shogo Kumagai | Tomohito Kameda | Toshikazu Shiratori | Toshiaki Yoshioka
Source: Journal of Material Cycles and Waste Management (article, 2023-07-25)
Field: Chemistry — Inorganic Chemistry

Fluorine recovery through alkaline defluorination of polyvinylidene fluoride Abstract The establishment of technological approaches for the defluorination of waste fluoropolymers and recovery of eliminated F – may contribute to the development of fluorine recycling routes. In this study, we investigated the effects of alkalinity, phase transfer catalyst (PTC) concentration, reaction temperature, and solvent types on the defluorination of polyvinylidene fluoride (PVDF) by alkaline wet processing. The rate of defluorination of PVDF in 4.0 M sodium hydroxide (NaOH) and 50 mM tetrabutylammonium bromide (TBAB) under aqueous conditions reached 89.2%. In addition, the defluorination reaction proceeded faster in solvents such as diethylene glycol (DEG) and triethylene glycol (TEG) than in water because of the high affinity between PVDF and these diols. To investigate the feasibility of developing a fluorine recycling route, the defluorination of a photovoltaic (PV) backsheet and subsequent CaF 2 precipitation from the eliminated F – was examined. A total of 88.3% of F contained in the PV backsheet was recovered as CaF 2 , which satisfied the quality standards of commercial fluorspar. This study demonstrated that alkaline wet processing is effective for the defluorination of PVDF and that the establishment of a F recycling route along the F supply chain may be feasible. Polyvinylidene fluoride ; Diethylene glycol ; Triethylene glycol ; Fluorine ; Fluoride ; Chemistry ; Alkalinity ; Solvent ; Sodium hydroxide ; Aqueous solution ; Nuclear chemistry ; Bromide ; Chemical engineering ; Inorganic chemistry ; Organic chemistry ; Ethylene glycol ; Polymer Inorganic Fluorides and Related Compounds ; Fiber-reinforced polymer composites ; Per- and polyfluoroalkyl substances research
Authors: Deborah T. Ogunleye | Samson O. Akpotu | Brenda Moodley
Source: ChemistrySelect (article, 2023-01-26)
Field: Materials Science — Biomaterials

Crystalline Nanocellulose Anchored on Reduced Graphene Oxide for the Removal of Pharmaceuticals from Aqueous Systems: Adsorbent Characterization and Adsorption Performance Abstract Improved adsorption of pharmaceuticals on reduced graphene oxide anchored on a crystalline nanocellulose base was achieved in this study. One‐pot synthesis of graphene‐nanocrystalline cellulose (G‐CNC) hybrid with in‐depth characterization was carried out, and the adsorbent's successful synthesis was confirmed through the characteristic peaks observed using FTIR and XRD. Further characterization was done using the surface area and porosity analyzer, TGA, SEM, TEM, and the elemental analyzer. The adsorbent was then applied in the adsorption of aspirin (Asp) and acetaminophen (Acet), which are frequently used over‐the‐counter anti‐inflammatory and antipyretic drugs. The major mechanism for the adsorption was ascertained to be through electrostatic interaction, hydrogen bonding, hydrophobic and π‐π interactions with the pharmaceutical. The maximum capacity for sorption obtained for the adsorption of Asp on graphene oxide (GO) and G‐CNC was 61.73 mg/g and 99 mg/g, respectively, while those of Acet on GO and G‐CNC were 20.41 mg/g and 76.34 mg/g, respectively. Adsorption ; Graphene ; Nanocellulose ; Chemical engineering ; Oxide ; Aqueous solution ; Materials science ; Fourier transform infrared spectroscopy ; Cellulose ; Sorption ; Nuclear chemistry ; Chemistry ; Organic chemistry ; Nanotechnology Advanced Cellulose Research Studies ; Graphene and Nanomaterials Applications ; Nanoparticle-Based Drug Delivery
Authors: Jie Liang | Hao Tan | Jia Liu | H. R. Qi | Xiaoming Li | Lingling Wu | Xiaoyun Xue | Guangcun Shan
Source: Materials Today Sustainability (article, 2023-10-04)
Field: Chemistry — Inorganic Chemistry

Combined experimental and theoretical studies on iodine capture of Zr-based metal-organic frameworks: Effect of N-functionalization and adsorption mechanism Adsorption ; X-ray photoelectron spectroscopy ; Surface modification ; Metal-organic framework ; Chemistry ; Iodine ; Desorption ; Pyridine ; Density functional theory ; Inorganic chemistry ; Metal ; Chemical engineering ; Organic chemistry ; Physical chemistry ; Computational chemistry Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Radioactive element chemistry and processing
Authors: Shangzhe Yu | Shidong Zhang | Dominik Schäfer | Roland Peters | Felix Kunz | Rüdiger‐A. Eichel
Source: Energies (article, 2023-04-29)
Field: Materials Science — Materials Chemistry

Numerical Modeling and Simulation of the Solid Oxide Cell Stacks and Metal Interconnect Oxidation with OpenFOAM Solid oxide cells are capable of efficiently converting various chemical energy carriers to electricity and vice versa. The urgent challenge nowadays is the faster degradation rate compared with other fuel cell/electrolyzer technologies. To understand the degradation mechanisms, simulation of a solid oxide cell is helpful. Since most previous research developed models using commercial software, such as COMSOL and ANSYS Fluent, a gap for knowledge transfer is being gradually formed between academia and industry due to licensing issues. This paper introduces a multiphysics model, developed by a computational code, openFuelCell2. The code is implemented with an open-source library, OpenFOAM. It accounts for momentum transfer, mass transfer, electrochemical reactions and metal interconnect oxidation. The model can precisely predict I–V curves under different temperatures, fuel humidity and operation modes. Comparison between OpenFOAM and COMSOL simulations shows good agreement. The metal interconnect oxidation is modeled, which can predict the thickness of the oxide scale under different protective coatings. Simulations are conducted by assuming an ultra-thin film resistance on the rib surface. It is revealed that coatings fabricated by atmospheric plasma spraying can efficiently prevent metal interconnect oxidation, with a contribution of only 0.53 % to the total degradation rate. Multiphysics ; Interconnection ; Oxide ; Materials science ; Solid oxide fuel cell ; Mechanical engineering ; Fluent ; Degradation (telecommunications) ; Electricity ; Nuclear engineering ; Computer science ; Process engineering ; Computer simulation ; Simulation ; Engineering ; Electronic engineering ; Electrical engineering ; Finite element method ; Metallurgy ; Chemistry ; Structural engineering Advancements in Solid Oxide Fuel Cells ; Fuel Cells and Related Materials ; Catalytic Processes in Materials Science
Authors: Y J Li | Miao Song | Peng Zhu | Yan-Ru Lin | Zehui Qi | Yajie Zhao | Samara M. Levine | S.J. Zinkle
Source: Journal of Nuclear Materials (article, 2023-08-04)
Field: Materials Science — Metals and Alloys

Flash electropolishing of BCC Fe and Fe-based alloys Electropolishing ; Materials science ; FOIL method ; Focused ion beam ; Transmission electron microscopy ; Flash (photography) ; Ion ; Structural material ; Metallurgy ; Nanotechnology ; Composite material ; Optics ; Chemistry ; Physics Hydrogen embrittlement and corrosion behaviors in metals ; Advanced Materials Characterization Techniques ; Semiconductor materials and devices
Authors: Aritra Chakraborty | Ricardo A. Lebensohn | Laurent Capolungo
Source: Journal of the Mechanics and Physics of Solids (article, 2023-01-06)
Field: Materials Science — Materials Chemistry

Coupled chemo-mechanical modeling of point-defect diffusion in a crystal plasticity fast Fourier transform framework Materials science ; Grain boundary diffusion coefficient ; Grain boundary ; Lattice diffusion coefficient ; Grain boundary strengthening ; Vacancy defect ; Grain size ; Diffusion creep ; Creep ; Effective diffusion coefficient ; Plasticity ; Condensed matter physics ; Mechanics ; Metallurgy ; Composite material ; Microstructure ; Physics Microstructure and mechanical properties ; High Temperature Alloys and Creep ; Aluminum Alloys Composites Properties
Authors: Mohamed T.‐E. Maghraby | Tahani Mazyad Almutairi | Stefan Bräse | Ola I. A. Salem | Bahaa G. M. Youssif | Mahmoud Sheha
Source: Molecules (article, 2023-10-14)
Field: Chemistry — Organic Chemistry

New 1,2,3-Triazole/1,2,4-triazole Hybrids as Aromatase Inhibitors: Design, Synthesis, and Apoptotic Antiproliferative Activity A novel series of 1,2,3-triazole/1,2,4-triazole hybrids 5a, 5b, and 6a-i was designed and synthesized as antiproliferative agents targeting aromatase enzymes. The antiproliferative activity of the new hybrids against four cancer cells was studied using Erlotinib as a control. Compounds 6a and 6b demonstrated the highest antiproliferative activity among these hybrids, with GI50 values of 40 nM and 35 nM, respectively. Compound 6b was the most potent derivative, with a GI50 of 35 nM, comparable to Erlotinib's GI50 of 33 nM. Compound 6b inhibited all cancer cell lines with comparable efficacy to Erlotinib. Compounds 5a, 5b, and 6a-i were tested for inhibitory action against aromatase as a potential target for their antiproliferative activity. Results revealed that compounds 6a and 6b were the most potent aromatase inhibitors, with IC50 values of 0.12 ± 0.01 µM and 0.09 ± 0.01 µM, respectively, being more potent than the reference Ketoconazole (IC50 = 2.6 ± 0.20 µM) but less potent than Letrozole (IC50 = 0.002 ± 0.0002). These findings indicated that compounds 6a and 6b had significant aromatase inhibitory action and are potential antiproliferative candidates. The findings were further linked to molecular docking investigations, which gave models of strong interactions with the aromatase domain for inhibitors with high binding scores. Aromatase ; Triazole ; Chemistry ; 1,2,3-Triazole ; Apoptosis ; Hybrid ; Combinatorial chemistry ; Biology ; Biochemistry ; Organic chemistry ; Botany ; Genetics Synthesis and biological activity ; Synthesis and Characterization of Heterocyclic Compounds ; Click Chemistry and Applications
Authors: Zhuang Li | Na Liu | Wanzhen Yang | Jie Tu | Yahui Huang | Wei Wang | Chunquan Sheng
Source: Acta Pharmaceutica Sinica B (article, 2023-02-21)
Field: Materials Science — Materials Chemistry

Controlling antifungal activity with light: Optical regulation of fungal ergosterol biosynthetic pathway with photo-responsive CYP51 inhibitors Invasive fungal infections (IFIs) have been associated with high mortality, highlighting the urgent need for developing novel antifungal strategies. Herein the first light-responsive antifungal agents were designed by optical control of fungal ergosterol biosynthesis pathway with photocaged triazole lanosterol 14<i>α</i>-demethylase (CYP51) inhibitors. The photocaged triazoles completely shielded the CYP51 inhibition. The content of ergosterol in fungi before photoactivation and after photoactivation was 4.4% and 83.7%, respectively. Importantly, the shielded antifungal activity (MIC<sub>80</sub> ≥ 64 μg/mL) could be efficiently recovered (MIC<sub>80</sub> = 0.5-8 μg/mL) by light irradiation. The new chemical tools enable optical control of fungal growth arrest, morphological conversion and biofilm formation. The ability for high-precision antifungal treatment was validated by <i>in vivo</i> models. The light-activated compound <b>A1</b> was comparable to fluconazole in prolonging survival in <i>Galleria mellonella</i> larvae with a median survival of 14 days and reducing fungal burden in the mouse skin infection model. Overall, this study paves the way for precise regulation of antifungal therapy with improved efficacy and safety. Ergosterol ; Antifungal ; Chemistry ; Microbiology ; Pharmacology ; Biochemistry ; Biology Photochromic and Fluorescence Chemistry ; Olfactory and Sensory Function Studies ; Radical Photochemical Reactions