jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Jeongmin Kim | Benjamin Rotenberg
Source: The Journal of Chemical Physics (article, 2024-08-01)
Field: Chemistry — Physical and Theoretical Chemistry

Donnan equilibrium in charged slit-pores from a hybrid nonequilibrium molecular dynamics/Monte Carlo method with ions and solvent exchange Ion partitioning between different compartments (e.g., a porous material and a bulk solution reservoir), known as Donnan equilibrium, plays a fundamental role in various contexts such as energy, environment, or water treatment. The linearized Poisson-Boltzmann (PB) equation, capturing the thermal motion of the ions with mean-field electrostatic interactions, is practically useful to understand and predict ion partitioning, despite its limited applicability to conditions of low salt concentrations and surface charge densities. Here, we investigate the Donnan equilibrium of coarse-grained dilute electrolytes confined in charged slit-pores in equilibrium with a reservoir of ions and solvent. We introduce and use an extension to confined systems of a recently developed hybrid nonequilibrium molecular dynamics/grand canonical Monte Carlo simulation method ("H4D"), which enhances the efficiency of solvent and ion-pair exchange via a fourth spatial dimension. We show that the validity range of linearized PB theory to predict the Donnan equilibrium of dilute electrolytes can be extended to highly charged pores by simply considering renormalized surface charge densities. We compare with simulations of implicit solvent models of electrolytes and show that in the low salt concentrations and thin electric double layer limit considered here, an explicit solvent has a limited effect on the Donnan equilibrium and that the main limitations of the analytical predictions are not due to the breakdown of the mean-field description but rather to the charge renormalization approximation, because it only focuses on the behavior far from the surfaces. Donnan potential ; Electrolyte ; Monte Carlo method ; Ion ; Chemistry ; Non-equilibrium thermodynamics ; Chemical physics ; Thermodynamics ; Electrostatics ; Molecular dynamics ; Range (aeronautics) ; Grand canonical ensemble ; Surface charge ; Poisson–Boltzmann equation ; Statistical physics ; Physics ; Materials science ; Computational chemistry ; Physical chemistry ; Electrode Electrostatics and Colloid Interactions ; Nanopore and Nanochannel Transport Studies ; Spectroscopy and Quantum Chemical Studies
Authors: Gastón Francucci | Elena Rodríguez González | María Eugenia Rodriguez
Source: Polymers (article, 2024-08-27)
Field: Materials Science — Polymers and Plastics

Ultrasound-Assisted Extrusion Compounding of Nano Clay/Polypropylene Nano Compounds The incorporation of nanoparticles can significantly enhance the properties of polymers. However, the industrial production of nanocomposites presents a technological challenge in achieving the proper dispersion of nanoparticles within the polymer matrix. In this work, a novel device is presented that can be seamlessly integrated with standard twin-screw extruders, enabling the application of ultrasonic vibration to molten polymeric material. The primary objective of this study is to experimentally validate the effectiveness of this technology in improving the dispersion of nanoparticles. To accomplish this, a comparative analysis was carried out between nanocomposites obtained through conventional compounding extrusion and those processed with the assistance of ultrasonic vibrations. The nanocomposites under investigation consist of a polypropylene (PP) matrix reinforced with nano clays (Cloisite 20A) at a target loading ratio of 5% by weight. To comprehensively evaluate the impact of the ultrasound-assisted compounding, various key properties were assessed, such as the melt flow index (MFI) to characterize the flow behavior, mechanical properties to evaluate the structural performance, oxygen barrier properties to assess potential gas permeability, and microstructure analysis using Scanning Electron Microscopy (SEM) for detailed morphology characterization. The results suggested an improvement in nanoparticle dispersion when using the ultrasound device, particularly when the intensity was adjusted to 60%. Materials science ; Extrusion ; Compounding ; Polypropylene ; Nanocomposite ; Plastics extrusion ; Composite material ; Nano- ; Dispersion (optics) ; Polymer ; Nanoparticle ; Microstructure ; Ultrasound ; Ultrasonic sensor ; Melt flow index ; Nanotechnology ; Copolymer Polymer Nanocomposites and Properties ; Polymer Nanocomposite Synthesis and Irradiation ; Dielectric materials and actuators
Authors: Ralph Freund | A. Schulz | P. Lunkenheimer | Maryana Kraft | Thomas Bergler | Harald Oberhofer | Dirk Volkmer
Source: Advanced Functional Materials (article, 2024-11-07)
Field: Chemistry — Electrochemistry

Exploring Dipolar Dynamics and Ionic Transport in Metal‐Organic Frameworks: Experimental and Theoretical Insights Abstract The present study examines the potential coupling between dipolar dynamics and ionic charge transport in metal‐organic framework (MOF) compounds. MOFs are known for their high porosity and customizable properties. By integrating freely rotating dipolar groups into the ligands, a novel structure, CFA‐25, akin to the known BUT‐2 framework, is synthesized. This facilitated the investigation of local and macroscopic effects, particularly the possible interplay between dipolar units and Cs cations. The research aimed to understand fundamental dipolar dynamics and ionic charge transport, employing Cs ions for their X‐ray diffraction characterizability. Experimental analysis using dielectric spectroscopy, complemented by theoretical simulations, explored questions regarding glassy freezing of re‐orientational dynamics, Cs cation motion within the network, and the influence of dipolar units on transport. Contrary to previous reports, this work finds that Cs transport exhibits substantial barriers, necessitating specialized simulation techniques for accurate characterization. This interdisciplinary approach sheds light on the intricate dynamics of MOFs and offers insights into their potential applications involving ion transport phenomena. Materials science ; Ionic bonding ; Dipole ; Chemical physics ; Dynamics (music) ; Metal-organic framework ; Nanotechnology ; Metal ; Molecular dynamics ; Ionic liquid ; Computational chemistry ; Physical chemistry ; Ion ; Organic chemistry ; Metallurgy ; Physics Electrochemical Analysis and Applications ; Ionic liquids properties and applications ; Material Dynamics and Properties
Authors: Valentin Bardoula | Loı̈c Leclercq | Richard Hoogenboom | Véronique Nardello‐Rataj
Source: Colloids and Surfaces A Physicochemical and Engineering Aspects (article, 2024-06-25)
Field: Materials Science — Materials Chemistry

Amphiphilic polymeric particles based on gradient and block copoly(2-oxazoline)s: Interplay between structure and Pickering emulsion properties Pickering emulsion ; Oxazoline ; Amphiphile ; Emulsion ; Block (permutation group theory) ; Polymer chemistry ; Materials science ; Copolymer ; Chemical engineering ; Polymer science ; Polymer ; Chemistry ; Organic chemistry ; Composite material ; Engineering ; Mathematics ; Combinatorics Pickering emulsions and particle stabilization ; Advanced Polymer Synthesis and Characterization ; Surfactants and Colloidal Systems
Authors: Benjamin J. Roman | Sofia A. Shubert | Delia J. Milliron
Source: MRS Bulletin (article, 2024-10-01)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Tunable optical response of plasmonic metal oxide nanocrystals Abstract This article is based on the MRS Medal presentation given by Delia J. Milliron at the 2023 MRS Fall Meeting &amp; Exhibit in Boston, Mass. Milliron is cited “for the development of optically tunable metal oxide nanomaterials for applications such as energy-saving electrochromic windows.” Doped metal oxide nanocrystals (NCs) provide a highly tunable platform for localized surface plasmon resonance (LSPR) in the near- to mid-IR. This tunability can be achieved synthetically, through the size, shape, and composition of the NCs, or post-synthetically through reversible redox reactions, enabling a host of emerging applications. While the broad strokes of this tunability have been understood for a decade, over the last few years, there has been tremendous progress in understanding the relationships between the electronic structure, defect chemistry, and synthetic and post-synthetic tunability of metal oxide NCs. This article aims to provide an up-to-date picture of the optical tunability of metal oxide NC LSPR, in particular focusing on recent insights into how the NC electronic structure plays a role in LSPR tunability. Graphical abstract Materials science ; Plasmon ; Nanocrystal ; Oxide ; Metal ; Optoelectronics ; Nanotechnology ; Metallurgy Gold and Silver Nanoparticles Synthesis and Applications ; Copper-based nanomaterials and applications ; Nonlinear Optical Materials Studies
Authors: Sébastien Berruée | Jean‐Michel Guigner | Thomas Bizien | Laurent Bouteiller | Lydia Sosa‐Vargas | Jutta Rieger
Source: Angewandte Chemie International Edition (article, 2024-10-08)
Field: Materials Science — Biomaterials

Spontaneous Formation of Polymeric Nanoribbons in Water Driven by π–π Interactions A simple method was developed to produce polymeric nanoribbons and other nanostructures in water. This approach incorporates a perylene diimide (PDI) functionalized by triethylene glycol (TEG) as a hydrophobic supramolecular structure directing unit (SSDU) into the core of hydrophilic poly(N,N-dimethylacrylamide) (PDMAc) chains using RAFT polymerization. All PDI-functional polymers dissolved spontaneously in water, forming different nanostructures depending on the degree of polymerization (DP<sub>n</sub>): nanoribbons and nanocylinders for DP<sub>n</sub>=14 and 22, and spheres for DP<sub>n</sub>>50 as determined by cryo-TEM and SAXS analyses. UV/Vis absorption spectroscopy was used to monitor the evolution of the PDI absorption signal upon dissolution. In solid form, all polymers show a H-aggregate absorption signature, but upon dissolution in water, the shortest DP<sub>n</sub> forming nanoribbons evolved to show HJ-aggregate absorption signals. Over time, the J-aggregate band increased in intensity, while cryo-TEM monitoring evidenced an increase in the nanoribbon's width. Heating the nanoribbons above 60 °C, triggered a morphological transition from nanoribbons to nanocylinders, due to the disappearance of J-aggregates, while H-aggregates were maintained. The study shows that the TEG-PDI is a powerful SSDU to promote 2D or 1D self-assembly of polymers depending on DP<sub>n</sub> through simple dissolution in water. Triethylene glycol ; Polymerization ; Diimide ; Perylene ; Polymer ; Raft ; Polymer chemistry ; Reversible addition−fragmentation chain-transfer polymerization ; Supramolecular chemistry ; Materials science ; Nanostructure ; Chemical engineering ; Chemistry ; Nanotechnology ; Molecule ; Radical polymerization ; Organic chemistry Supramolecular Self-Assembly in Materials ; Supramolecular Chemistry and Complexes ; Pickering emulsions and particle stabilization
Authors: Shuyu Lin | Zhihai Wu | Fan Yang | Jin Fu | Yang‐Xin Yu | Jing Wang | Lan Xiang
Source: Small (article, 2024-03-03)
Field: Materials Science — Materials Chemistry

Synthesis and Mechanism of 1D ZnO Based on Alkaline Dissolution‐Conversion Strategy of High Stable and Soluble ɛ‐Zn(OH)<sub>2</sub> A high soluble and stable ɛ-Zn(OH)<sub>2</sub> precursor is synthesized at below room temperature to efficiently prepare ZnO whiskers. The experimental results indicate that the formation of ZnO whiskers is carried out mainly via two steps: the formation of ZnO seeds from ɛ-Zn(OH)<sub>2</sub> via the in situ solid conversion, and the following growth of whiskers via dissolution-precipitation route. The decrease of temperature from 25 to 5 °C promotes the formation of ɛ-Zn(OH)<sub>2</sub> with higher solubility and stability, which balances the conversion and dissolution rates of precursor. The Rietveld refinement, DFT calculations and MD simulations reveal that the primary reason for these characteristics is the expansion of ɛ-Zn(OH)<sub>2</sub> lattice due to temperature, causing difficulties in the dehydration of adjacent ─OH. Simultaneously, the larger specific surface area favors the dissolution of ɛ-Zn(OH)<sub>2</sub>. Based on this precursor, well-dispersed ZnO whiskers with 9.82 µm in length, 242.38 nm in diameter, and an average aspect ratio of 41 are successfully synthesized through a SDSN-assisted hydrothermal process at 80 °C. The process has an extremely high solid content of 2.5% (mass ratio of ZnO to solution) and an overall yield of 92%, which offers a new approach for the scaled synthesis of high aspect ratio ZnO whiskers by liquid-phase method. Whiskers ; Dissolution ; Materials science ; Solubility ; Chemical engineering ; Precipitation ; Hydrothermal circulation ; Yield (engineering) ; Rietveld refinement ; Zinc ; Crystallography ; Crystal structure ; Physical chemistry ; Chemistry ; Metallurgy ; Composite material ZnO doping and properties ; Gas Sensing Nanomaterials and Sensors ; Copper-based nanomaterials and applications
Authors: Anzhela Galstyan
Source: Chemistry - A European Journal (article, 2024-07-22)
Field: Materials Science — Materials Chemistry

Tracking Microenvironmental Response on Self‐Assembled Phthalocyanine Systems – Adaptive and Non‐Adaptive Antibacterial Photosensitization Self-assembly has proven to be one of the effective methods for the formation of nanoscale therapeutics without the need to use nanodelivery systems. Such minimal models of supramolecular systems formed from amphiphilic photosensitizers (PS) have recently emerged as a new class of photoactive systems, providing unique and in some cases superior activities. Although the mechanism of photogenerated reactive oxygen species (ROS) in such systems is studied and to a certain extent understood, there are very limited studies investigating the influence of intricate environmental factors, including those occurring in the cellular environment, on the self-assembly and thus the activity of the system. Understanding the optimal conditions for the formation of active PS aggregates is an important area of research in the field of photodynamic therapy (PDT), as it is directly linked to the optimal treatment dose. In this study, we describe the synthesis, self-assembly properties, photophysical characterization, and photobiological efficacy of structurally closely related low-symmetry phthalocyanine derivatives. Studying the decay behavior of the PS fluorescence lifetime in the presence of molecular crowders and different bacterial strains, we found that certain derivatives exhibited adaptive behavior and change in activity, while others demonstrated non-adaptive characteristics. Phthalocyanine ; Photodynamic therapy ; Supramolecular chemistry ; Self-assembly ; Amphiphile ; Nanotechnology ; Fluorescence ; Chemistry ; Materials science ; Biophysics ; Combinatorial chemistry ; Molecule ; Polymer ; Organic chemistry ; Biology ; Physics Porphyrin and Phthalocyanine Chemistry ; Nanoplatforms for cancer theranostics ; Photodynamic Therapy Research Studies
Authors: Ferenc Kubicsek | Áron Kozák | Tamás Turányi | István Gy. Zsély | Máté Papp | Ahmad Al-Awamleh | Ferenc Hegedűs
Source: Ultrasonics Sonochemistry (article, 2024-04-14)
Field: Materials Science — Materials Chemistry

Ammonia production by microbubbles: A theoretical analysis of achievable energy intensity The present paper studies the energy intensity of ammonia production by a freely oscillating microbubble placed in an infinite domain of liquid. The initial content of the bubble is a mixture of hydrogen and nitrogen. The bubble is expanded isothermically to a maximum radius, then it is "released" and oscillates freely. The input energy is composed of the potential energy of the bubble at the maximum radius, the energy required to produce hydrogen, and the pumping work in case a vacuum is employed. The chemical yield is computed by solving the underlying governing equations: the Keller-Miksis equation for the radial dynamics, the first law of thermodynamics for the internal temperature and the reaction mechanism for the evolution of the concentration of the chemical species. The control parameters during the simulations are the equilibrium bubble size, initial expansion ratio, ambient pressure, the initial concentration ratio of hydrogen and the material properties of the liquid. At the optimal parameter setup, the energy intensity is 90.17GJ/t that is 2.31 times higher than the best available technology, the Haber-Bosch process. In both cases, the hydrogen is generated via water electrolysis. Bubble ; Hydrogen ; Hydrogen production ; RADIUS ; Work (physics) ; Chemistry ; Intensity (physics) ; Thermodynamics ; Yield (engineering) ; Electrolysis ; Mechanics ; Materials science ; Physics ; Electrode ; Physical chemistry Ultrasound and Cavitation Phenomena ; Industrial Gas Emission Control ; Fluid Dynamics and Mixing
Authors: Parham Koochak | Mariia S. Kiseleva | Sakari Lepikko | Mika Latikka | Robin H. A. Ras | William S. Y. Wong
Source: Advanced Materials Interfaces (article, 2024-11-04)
Field: Materials Science — Surfaces, Coatings and Films

Smoothening Perfluoroalkylated Surfaces: Liquid‐Like Despite Molecular Rigidity? Abstract The rational design of surfaces at the molecular level is essential toward realizing many engineering applications. However, molecular‐scale defects affect processes such as triboelectrification, scaling, and condensation. These defects are often detectable via contact angle hysteresis (CAH) measurements. Liquid‐like surfaces exhibit extremely low CAH (≤5°) and rely on the use of highly flexible molecular species such as long‐chain alkyls or siloxanes. Their low glass transition temperatures lead to the so‐termed self‐smoothing behavior, reducing sensitivity to defects formed during fabrication. However, utilizing rigid molecular species such as perfluoroalkyl chains often results in higher hysteresis (10° to 60°) as defects are not self‐smoothed after fabrication. Consequently, state‐of‐the‐art perfluoroalkylated surfaces often show sub‐optimal interfacial properties. Here, a customizable chemical vapor deposition process creates molecularly‐thick, low‐defect surfaces from trichloro(1 H ,1 H ,2 H ,2 H ‐perfluorooctyl)silane. By implementing moisture‐exposure controls, highly homogenous surfaces with root‐mean‐square roughness below 1 nm are fabricated. CAH is achieved down to ≈4° (average: 6°), surpassing the state‐of‐the‐art by ≈5°. Reduction of CAH (26° to 6°) results in condensation suppression, decreasing surface droplet density by one order and surface droplet coverage by 40%. This work guides the synthesis of high‐quality surfaces from tri‐functional perfluoroalkylsilanes with liquid‐like properties despite their molecular rigidity. Materials science ; Rigidity (electromagnetism) ; Nanotechnology ; Composite material ; Chemical engineering ; Engineering Surface Modification and Superhydrophobicity ; Adhesion, Friction, and Surface Interactions ; Polymer Surface Interaction Studies
Authors: Ángel Rentería‐Gómez | Rubén O. Torres‐Ochoa | Pierre Palamini | Raphaël Simonet‐Davin | Qian Wang | Jérôme Waser | Jieping Zhu
Source: Helvetica Chimica Acta (article, 2024-02-09)
Field: Chemistry — Organic Chemistry

Benzylic C(sp<sup>3</sup>)−H Azidation: Copper <i>vs</i> Iron Catalysis Abstract The generation of benzylic radicals through hydrogen atom abstraction (HAT) has been a recent research focus and various C(sp 3 )−H bond functionalization protocols have been developed relying on this elementary step. We report herein copper‐ and iron‐catalyzed C(sp 3 )−H benzylic azidation reactions using m CPBA and NFSI as oxidant, respectively, and TMSN 3 as azide source. The reaction is thought to be initiated via intermolecular abstraction of benzylic hydrogen by the in situ generated heteroatom‐centered radicals. The Fe(OTf) 3 ‐catalyzed azidation protocol displays good chemoselectivity as it takes place preferentially at the secondary and tertiary benzylic C(sp 3 )−H bonds over the primary benzylic and tertiary aliphatic carbons. Efforts on the development of catalytic enantioselective processes are also documented. Chemistry ; Copper ; Catalysis ; Combinatorial chemistry ; Medicinal chemistry ; Organic chemistry Oxidative Organic Chemistry Reactions ; Synthesis and Catalytic Reactions ; Chemical Reactions and Isotopes
Authors: Geeta Sharma | Sarathkumar Loganathan | Eric Kumi‐Barimah | Paraskevi Georgopoulou | Esther Taylor | A.J. Scott | S.M. Strafford | Animesh Jha
Source: ChemPhysChem (article, 2024-06-18)
Field: Materials Science — Materials Chemistry

Effect of Rare Earth Ion Substitution on Phase Decomposition of Apatite Structure The paper describes an investigation of phase decomposition of apatite lattice doped with rare earth ions (cerium, samarium, and holmium) at temperatures ranging from 25-1200 °C. The rare-earth ion-doped apatite minerals were synthesized using the sol-gel method. In situ high-temperature powder X-ray diffraction (XRD) was used to observe the phase changes and the lattice parameters were analyzed to ascertain the crystallographic transformations. The expansion coefficient of the compounds was determined, and it was found that the c-axis was the most expandable due to relatively weak chemical bonds along the c-crystallographic axis. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to examine the decomposition properties of the materials. Due to rare earth ion doping, the produced materials had slightly variable decomposition behaviour. The cerium and samarium ions were present in multiple oxidation states (Ce<sup>3+</sup>, Ce<sup>4+</sup>, Sm<sup>3+</sup>, Sm<sup>2+</sup>), whereas only Ho<sup>3+</sup> ions were observed. Rare earth ion substitution affects tri-calcium phosphate proportion during decomposition by regulating concentrations of vacancies. X-ray photoelectron spectroscopy (XPS) analysis indicated that cerium and samarium ion-doped apatite yielded only 25 % tricalcium phosphate during decomposition. This finding advances our understanding of apatite structures, with implications for various high-temperature processes like calcination, sintering, hydrothermal processing, and plasma spraying. Cerium ; Samarium ; Apatite ; Differential scanning calorimetry ; Materials science ; Thermogravimetric analysis ; X-ray photoelectron spectroscopy ; Calcination ; Thermal decomposition ; Powder diffraction ; Lanthanide ; Analytical Chemistry (journal) ; Inorganic chemistry ; Mineralogy ; Ion ; Chemistry ; Crystallography ; Chemical engineering ; Metallurgy ; Organic chemistry Nuclear materials and radiation effects ; Thermal and Kinetic Analysis ; Luminescence Properties of Advanced Materials