jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Zhixi Li | Bingqing Yao | Chuanqi Cheng | Meina Song | Yutian Qin | Yue Wan | Jing Du | Chaoyang Zheng | Liyun Xiao | Shaopeng Li | Pengfei Yin | Jun Guo | Z.Y. Liu | Meiting Zhao | Wei Huang
Source: Advanced Materials (article, 2023-12-18)
Field: Chemistry — Inorganic Chemistry

Versatile Structural Engineering of Metal–Organic Frameworks Enabling Switchable Catalytic Selectivity The structure engineering of metal-organic frameworks (MOFs) forms the cornerstone of their applications. Nonetheless, realizing the simultaneous versatile structure engineering of MOFs remains a significant challenge. Herein, a dynamically mediated synthesis strategy to simultaneously engineer the crystal structure, defect structure, and nanostructure of MOFs is proposed. These include amorphous Zr-ODB nanoparticles, crystalline Zr-ODB-hz (ODB = 4,4'-oxalyldibenzoate, hz = hydrazine) nanosheets, and defective d-Zr-ODB-hz nanosheets. Aberration-corrected scanning transmission electron microscopy combined with low-dose high-angle annular dark-field imaging technique vividly portrays these engineered structures. Concurrently, the introduced hydrazine moieties confer self-reduction properties to the respective MOF structures, allowing the in situ installation of catalytic Pd nanoparticles. Remarkably, in the hydrogenation of vanillin-like biomass derivatives, Pd/Zr-ODB-hz yields partially hydrogenated alcohols as the primary products, whereas Pd/d-Zr-ODB-hz exclusively produces fully hydrogenated alkanes. Density functional theory calculations, coupled with experimental evidence, uncover the catalytic selectivity switch triggered by the change in structure type. The proposed strategy of versatile structure engineering of MOFs introduces an innovative pathway for the development of high-performance MOF-based catalysts for various reactions. Materials science ; Catalysis ; Selectivity ; Metal-organic framework ; Nanotechnology ; Nanoparticle ; Nanostructure ; Palladium ; Hydrazine (antidepressant) ; Chemical engineering ; Organic chemistry ; Chemistry Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Catalysis and Hydrodesulfurization Studies
Authors: Francisco Narciso | Sara Cardoso | Nuno Monge | Madalena Lourenço | Víctor Martín | Noélia Duarte | Catarina Santos | Pedro Sousa Gomes | Ana Bettencourt | Isabel Ribeiro
Source: Colloids and Surfaces B Biointerfaces (article, 2023-07-31)
Field: Chemistry — Organic Chemistry

3D-printed biosurfactant-chitosan antibacterial coating for the prevention of silicone-based associated infections Biocompatibility ; Chitosan ; Antibacterial activity ; Antimicrobial ; Materials science ; Coating ; Silicone ; Polydimethylsiloxane ; Chemistry ; Nanotechnology ; Bacteria ; Composite material ; Organic chemistry Antimicrobial agents and applications ; Bacterial biofilms and quorum sensing ; Microplastics and Plastic Pollution
Authors: Sheikh Mohd. Ta-Seen Afrid
Source: Heliyon (article, 2023-12-07)
Field: Materials Science — Materials Chemistry

Defect engineered magnetism induction and electronic structure modulation in monolayer MoS2 The electronic, magnetic, and optical characteristics of a defective monolayer MoS<sub>2</sub> were examined by employing density functional theory (DFT)-based first-principles calculations. The effects of several defects on the electrical, magnetic, and optical properties, including Mo vacancies, MoS<sub>3</sub> vacancies, and the substitution of a single Mo atom by two S atoms were studied in this work. Our first-principles calculations revealed that different types of defects produced distinct energy states within the band gap, leading to a band gap reduction after the introduction of various types of defects, which caused a change from semiconducting to metallic behavior. The spin-up and spin-down states were separated in the case of MoS<sub>3</sub> vacancy. The total magnetization was ∼ -0.83 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>μ</mml:mi></mml:mrow><mml:mrow><mml:mi>B</mml:mi></mml:mrow></mml:msub></mml:math>/cell, and the absolute magnetization was ∼ 1.23 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>μ</mml:mi></mml:mrow><mml:mrow><mml:mi>B</mml:mi></mml:mrow></mml:msub></mml:math>/cell. Moreover, spin-up states had a 0.45 eV band gap, whereas spin-down states were metallic. Consequently, it can be promising for spin filter applications. It was disclosed that the broadband part of the electromagnetic spectrum has a high absorption coefficient, which is necessary for applications including impurity detection, photodiodes, and solar cells. Designing spintronic and optoelectronic devices will benefit from the modification of the electrical, optical, and magnetic properties by defect engineering of MoS<sub>2</sub> monolayers presented here. Magnetism ; Monolayer ; Modulation (music) ; Materials science ; Condensed matter physics ; Physics ; Nanotechnology 2D Materials and Applications ; MXene and MAX Phase Materials ; Heusler alloys: electronic and magnetic properties
Authors: Joseph J. Barchi | Caitlin N. Strain
Source: Frontiers in Molecular Biosciences (review, 2023-02-10)
Field: Chemistry — Organic Chemistry

The effect of a methyl group on structure and function: Serine vs. threonine glycosylation and phosphorylation A variety of glycan structures cover the surface of all cells and are involved in myriad biological processes, including but not limited to, cell adhesion and communication, protein quality control, signal transduction and metabolism, while also being intimately involved in innate and adaptive immune functions. Immune surveillance and responses to foreign carbohydrate antigens, such as capsular polysaccharides on bacteria and surface protein glycosylation of viruses, are the basis of microbial clearance, and most antimicrobial vaccines target these structures. In addition, aberrant glycans on tumors called Tumor-Associated Carbohydrate Antigens (TACAs) elicit immune responses to cancer, and TACAs have been used in the design of many antitumor vaccine constructs. A majority of mammalian TACAs are derived from what are referred to as mucin-type O-linked glycans on cell-surface proteins and are linked to the protein backbone through the hydroxyl group of either serine or threonine residues. A small group of structural studies that have compared mono- and oligosaccharides attached to each of these residues have shown that there are distinct differences in conformational preferences assumed by glycans attached to either "unmethylated" serine or <i>ß</i>-methylated threonine. This suggests that the linkage point of antigenic glycans will affect their presentation to the immune system as well as to various carbohydrate binding molecules (e.g., lectins). This short review, followed by our hypothesis, will examine this possibility and extend the concept to the presentation of glycans on surfaces and in assay systems where recognition of glycans by proteins and other binding partners can be defined by different attachment points that allow for a range of conformational presentations<b>.</b> Threonine ; Phosphorylation ; Serine ; Glycosylation ; Chemistry ; Biochemistry ; Protein phosphorylation ; Protein kinase A Carbohydrate Chemistry and Synthesis ; Amino Acid Enzymes and Metabolism ; Cancer-related gene regulation
Authors: Angelica P. Orlova | Maxwell S. Varley | Maximilian G. Bernbeck | Kyle M. Kirkpatrick | Philip C. Bunting | Milan Gembický | Jeffrey D. Rinehart
Source: Journal of the American Chemical Society (article, 2023-09-29)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Molecular Network Approach to Anisotropic Ising Lattices: Parsing Magnetization Dynamics in Er<sup>3+</sup> Systems with 0–3-Dimensional Spin Interactivity We present a wide-ranging interrogation of the border between single-molecule and solid-state magnetism through a study of erbium-based Ising-type magnetic compounds with a fixed magnetic unit, using three different charge-balancing cations as the means to modulate the crystal packing environment. Properties rooted in the isolated spin Hamiltonian remain fixed, yet careful observation of the dynamics reveals the breakdown of this approximation in a number of interesting ways. First, differences in crystal packing lead to a striking 3 orders of magnitude suppression in magnetic relaxation rates, indicating a rich interplay between intermolecular interactions governed by the anisotropic Ising lattice stabilization and localized slow magnetic relaxation driven by the spin-forbidden nature of quantum tunneling of the f-electron-based magnetization. By means of diverse and rigorous physical methods, including temperature-dependent X-ray crystallography, field, temperature, and time-dependent magnetometry, and the application of a new magnetization fitting technique to quantify the magnetic susceptibility peakshape, we are able to construct a more nuanced view of the role nonzero-dimensional interactions can play in what are predominantly considered zero-dimensional magnetic materials. Specifically, we use low field susceptibility and virgin-curve analysis to isolate metamagnetic spin-flip transitions in each system with a field strength corresponding to the expected strength of the internal dipole-dipole lattice. This behavior is vital to a complete interpretation of the dynamics and is likely common for systems with such high anisotropy. This collective interactivity opens a new realm of possibility for molecular magnetic materials, where their unprecedented localized anisotropy is the determining factor in building higher dimensionality. Condensed matter physics ; Magnetization ; Chemistry ; Ising model ; Magnetism ; Magnetic anisotropy ; Spin ice ; Physics ; Magnetic field ; Quantum mechanics ; Magnetic monopole Magnetism in coordination complexes ; Lanthanide and Transition Metal Complexes ; Organic and Molecular Conductors Research
Authors: Kelly Cristina Coelho de Carvalho Benini | Anne Shayene Campos de Bomfim | Herman Jacobus Cornelis Voorwald
Source: Polymers (review, 2023-09-30)
Field: Materials Science — Biomaterials

Cellulose-Reinforced Polylactic Acid Composites for Three-Dimensional Printing Using Polyethylene Glycol as an Additive: A Comprehensive Review Growing concerns about environmental issues and global warming have garnered increased attention in recent decades. Consequently, the use of materials sourced from renewable and biodegradable origins, produced sustainably, has piqued the interest of scientific researchers. Biodegradable and naturally derived polymers, such as cellulose and polylactic acid (PLA), have consistently been the focus of scientific investigation. The objective is to develop novel materials that could potentially replace conventional petroleum-based polymers, offering specific properties tailored for diverse applications while upholding principles of sustainability and technology as well as economic viability. Against this backdrop, the aim of this review is to provide a comprehensive overview of recent advancements in research concerning the use of polylactic acid (PLA) and the incorporation of cellulose as a reinforcing agent within this polymeric matrix, alongside the application of 3D printing technology. Additionally, a pivotal additive in the combination of PLA and cellulose, polyethylene glycol (PEG), is explored. A systematic review of the existing literature related to the combination of these materials (PLA, cellulose, and PEG) and 3D printing was conducted using the Web of Science and Scopus databases. The outcomes of this search are presented through a comparative analysis of diverse studies, encompassing aspects such as the scale and cellulose amount added into the PLA matrix, modifications applied to cellulose surfaces, the incorporation of additives or compatibilizing agents, variations in molecular weight and in the quantity of PEG introduced into the PLA/cellulose (nano)composites, and the resulting impact of these variables on the properties of these materials. Polylactic acid ; Cellulose ; Polyethylene glycol ; Materials science ; PEG ratio ; Polymer ; Polymer science ; Composite material ; Chemical engineering ; Engineering ; Business biodegradable polymer synthesis and properties ; Advanced Cellulose Research Studies ; Additive Manufacturing and 3D Printing Technologies
Authors: Mohammed Mohammed | Jawad K. Oleiwi | Anwar Ja’afar Mohamad Jawad | Aeshah M. Mohammed | Azlin Fazlina Osman | Rozyanty Rahman | Tijjani Adam | Bashir O. Betar | Subash C.B. Gopinath | Omar S. Dahham
Source: Heliyon (article, 2023-09-01)
Field: Materials Science — Polymers and Plastics

Effect of zinc oxide surface treatment concentration and nanofiller loading on the flexural properties of unsaturated polyester/kenaf nanocomposites Due to environmental concerns and budgetary constraints associated with synthetic fibers, natural fibers (NFr) are becoming increasingly popular as reinforcement in polymer composites (PCs) for structural components and construction materials. The surface treatment (ST) method is a well-established technique for enhancing the strength of interfacial bonding between NFr and the polymer matrix (PM). As a result, this research aims to determine the effect of ST with zinc oxide nanoparticles (ZnONPs) on the flexural properties of unsaturated polyester (UPE)/kenaf fiber (KF) nanocomposites. The hand lay-up technique was employed to produce KF-reinforced unsaturated polyester composites (KF/UPE) for this investigation. UPE/KF-ZnONPs composites were made with varying NFr loadings (weight percent), ranging from 10 to 40%. KF was treated with five distinct amounts of ZnONPs (from 1 to 5% weight percent). According to the findings of the investigation, the composite samples incorporating ZnONPs displayed superior optimum flexural properties compared to the untreated KF composite. It was found that 2% ZnONPs was optimal, and ST with ZnONPs could produce robust KF with improved flexural properties. Flexural strength ; Materials science ; Kenaf ; Composite material ; Composite number ; Nanocomposite ; Zinc ; Polyester ; Polymer ; Fiber Natural Fiber Reinforced Composites ; Tribology and Wear Analysis ; Mechanical Engineering and Vibrations Research
Authors: Naba Abuhafez | Andreas W. Ehlers | Bas de Bruin | Rafael Gramage‐Doria
Source: Angewandte Chemie International Edition (article, 2023-12-01)
Field: Chemistry — Organic Chemistry

Markovnikov‐Selective Cobalt‐Catalyzed Wacker‐Type Oxidation of Styrenes into Ketones under Ambient Conditions Enabled by Hydrogen Bonding The replacement of palladium catalysts for Wacker-type oxidation of olefins into ketones by first-row transition metals is a relevant approach for searching more sustainable protocols. Besides highly sophisticated iron catalysts, all the other first-row transition metal complexes have only led to poor activities and selectivities. Herein, we show that the cobalt-tetraphenylporphyrin complex is a competent catalyst for the aerobic oxidation of styrenes into ketones with silanes as the hydrogen sources. Remarkably, under room temperature and air atmosphere, the reactions were exceedingly fast (up to 10 minutes) with a low catalyst loading (1 mol %) while keeping an excellent chemo- and Markovnikov-selectivity (up to 99 % of ketone). Unprecedently high TOF (864 h<sup>-1</sup> ) and TON (5,800) were reached for the oxidation of aromatic olefins under these benign conditions. Mechanistic studies suggest a reaction mechanism similar to the Mukaiyama-type hydration of olefins with a change in the last fundamental step, which controls the chemoselectivity, thanks to a unique hydrogen bonding network between the ethanol solvent and the cobalt peroxo intermediate. Markovnikov's rule ; Catalysis ; Chemistry ; Cobalt ; Chemoselectivity ; Silanes ; Ketone ; Transition metal ; Solvent ; Palladium ; Selectivity ; Organic chemistry ; Photochemistry ; Combinatorial chemistry ; Polymer chemistry ; Regioselectivity Catalytic C–H Functionalization Methods ; Oxidative Organic Chemistry Reactions ; Asymmetric Hydrogenation and Catalysis
Authors: Povilas Bertašius | Artyom Plyushch | J. Macutkevič | J. Banys | Algirdas Selskis | Oskars Platnieks | Sergejs Gaidukovs
Source: Polymers (article, 2023-02-20)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Multilayered Composites with Carbon Nanotubes for Electromagnetic Shielding Application Bulk polylactic acid (PLA)/multiwall carbon nanotube (MWCNT) composites were prepared and investigated in wide frequency ranges (20 Hz-1 MHz and 24-40 GHz). It was determined that the percolation threshold in bulk PLA/MWCNT composites is close to 0.2 vol.% MWCNT. However, the best microwave dielectric properties and absorption were observed in composites with 3.0-5.0 vol.% MWCNT. Therefore, for future investigations, we selected layered (laminate) polymeric structures with gradual changes in MWCNT concentration from 0.2 to 8.0 vol.% MWCNT. Two approaches to laminate structure designs were examined and compared: a five-layer composite and a nine-layer composite that included four pure PLA middle layers. The addition of MWCNT enhanced the elastic modulus by up to 1.4-fold and tensile strength by up to 1.2-fold, with the best performance achieved at 5.0 vol.% loading. High microwave shielding was observed for these layered PLA/MWCNT structures with a gradient change in MWCNT concentration (up to 26 dB in both transmission and absorption coefficients) in the broad frequency range (from 24 to 40 GHz). Obtained structures are highly anisotropic, and the absorption coefficient is 2-5 dB higher in the direction of MWCNT concentration increase; however, the transmission coefficient is the same in both directions. The properties of microwave absorption are mainly unaffected by the additional polymeric layers. The absorption of the layered structure is greater than the absorption of single-layer composites with an optimal MWCNT concentration of the same thickness. The proposed laminate structure design is promising in the field of efficient electromagnetic shielding. Composite material ; Electromagnetic shielding ; Materials science ; Carbon nanotube ; Carbon fibers ; Composite number Electromagnetic wave absorption materials ; Advanced Energy Technologies and Civil Engineering Innovations ; Material Properties and Applications
Authors: Yubin Kim | PilHo Huh | Seong Il Yoo
Source: Macromolecular Chemistry and Physics (article, 2023-01-10)
Field: Materials Science — Biomaterials

Mechanical Reinforcement of Thermoplastic Polyurethane Nanocomposites by Surface‐Modified Nanocellulose Abstract Utilization of biodegradable nanofillers is an emerging approach for the sustainable development of polymer composites. Among numerous green nanofillers, nanocellulose has garnered significant attention because of its abundance, high mechanical strength, and reinforcing capability. However, the intrinsic hydrophilicity of nanocellulose often restricts its homogeneous dispersion in the hydrophobic polymer matrix, resulting in a poor reinforcement effect. In this study, a simple surface modification of cellulose nanofibrils (CNFs) using small hydrophobic molecules is presented. Hydrophobic‐modified CNFs have better solubility in organic solvents and exhibit homogeneous dispersion in a thermoplastic polyurethane (TPU) matrix. The molecular interaction between CNFs and the hard/soft segments (HS/SS) of TPU induces surface‐mediated crystallization with improved microphase separation of SS and HS. By bridging multiple HS and SS microdomains, hydrophobic‐modified CNFs improve the tensile modulus and ultimate tensile strength of the polymer nanocomposites. On the other hand, unmodified CNFs are strongly aggregated in the TPU matrix, which restricts the mechanical reinforcement. These results demonstrate that surface modification of nanocelluloses can engineer their dispersion state and interfacial interaction with matrix polymers, which are crucial for the mechanical reinforcement of polymer nanocomposites. Materials science ; Nanocellulose ; Nanocomposite ; Thermoplastic polyurethane ; Ultimate tensile strength ; Composite material ; Polymer ; Surface modification ; Thermoplastic elastomer ; Thermoplastic ; Elastomer ; Cellulose ; Chemical engineering ; Copolymer Advanced Cellulose Research Studies ; Electrospun Nanofibers in Biomedical Applications ; biodegradable polymer synthesis and properties
Authors: Pengyun Liu | Zhilin Wu | Zhen Fang | Giancarlo Cravotto
Source: Ultrasonics Sonochemistry (article, 2023-07-25)
Field: Materials Science — Materials Chemistry

Sonolytic degradation kinetics and mechanisms of antibiotics in water and cow milk Antibiotics (ABX) residues frequently occurred in water and cow milk. This work aims to understand the kinetics and mechanisms of sonolytic degradation of four ABX, i.e. ceftiofur hydrochloride (CEF), sulfamonomethoxine sodium (SMM), marbofloxacin (MAR), and oxytetracycline (OTC) in water and milk. In both water and milk, the sonolytic degradation of ABX follows pseudo-first order (PFO) kinetics well (R<sup>2</sup>: 0.951-0.999), with significantly faster ABX degradation in water (PFO kinetics constants (k<sub>1</sub>): 1.5 × 10<sup>-3</sup>-1.2 × 10<sup>-1</sup> min<sup>-1</sup>) than in milk (k<sub>1</sub>: 3.5 × 10<sup>-4</sup>-5.6 × 10<sup>-2</sup> min<sup>-1</sup>). The k<sub>1</sub> values for SMM degradation in water increased by 118% with ultrasonic frequency (40-120 kHz), 174% with ultrasonic frequency (80-500 kHz), 649% with ultrasonic power (73-259 W), 22% with bulk temperature (12-40℃), and by 68% with reaction volume (50-250 mL), respectively, in other things being equal. The relevant k<sub>1</sub> values in milk increased by 326%, 231%, 122%, 10% as well as 82% with the above same effective factors, respectively. The oxidation by free radicals generated in situ dominates ABX degradation, and the hydrophobic CEF (54.0-971.7 nM min<sup>-1</sup>) and SMM (39.2-798.4 nM min<sup>-1</sup>) underwent faster degradation than the hydrophilic MAR (33.9-751.9 nM min<sup>-1</sup>) and OTC (33.8-545.3 nM min<sup>-1</sup>) in both water and milk. Adding an extra 0.5 mM H<sub>2</sub>O<sub>2</sub> accelerated SMM degradation by 19% in water and 33% in milk. After 130-150 min sonication of 100 mL of 2.0 mg L<sup>-1</sup> (6.62 μM) SMM in various milk with 500 kHz and 259 W, the residue concentrations (52.9-96.3 μg L<sup>-1</sup>) can meet the relevant maximum residue limit (100 μg L<sup>-1</sup>). Chemistry ; Kinetics ; ABX test ; Degradation (telecommunications) ; Sonication ; Nuclear chemistry ; Chromatography Ultrasound and Cavitation Phenomena ; Advanced oxidation water treatment ; Innovative Microfluidic and Catalytic Techniques Innovation
Authors: Anouk Martin | P. Lalanne | Amélie Weber-Vax | Angela Mutschler | Sébastien Lecommandoux
Source: International Journal of Pharmaceutics (article, 2023-06-21)
Field: Chemistry — Organic Chemistry

Controlling polymersome size through microfluidic-assisted self-assembly: Enabling ‘ready to use’ formulations for biological applications Polymersome ; Vesicle ; Microfluidics ; Dynamic light scattering ; Copolymer ; Aqueous solution ; Materials science ; Solvent ; Nanotechnology ; Ethylene glycol ; Chemical engineering ; Chemistry ; Nanoparticle ; Amphiphile ; Membrane ; Organic chemistry ; Polymer Advanced Polymer Synthesis and Characterization ; Polymer Surface Interaction Studies ; Microfluidic and Capillary Electrophoresis Applications