jablonkagroup/rise_ai_scientists huggingface dataset:
Source: Malaysian Journal of Chemistry (article, 2023-12-23)
Field: Materials Science — Materials Chemistry

The Influence of Alkali Treatment and Multi Fraction Cantala Fiber Reinforced Carbon Nanotube Composite on Mechanical Properties and Morphological The aim of the study was to determine the effect of alkali treatment and multi-fraction on tensile strength, flexure, modulus of elasticity, SEM, and water absorption in composites reinforced with carbon nanotubes.The fibers were extracted manually from 9 months old cantala leaves.6 wt% sodium hydroxide and distilled water were prepared to soak the fiber for 6 hours.The fibers were dried in the open air for 72 hours and put in an oven for 6 hours at 60 o C. Carbon nanotubes (CNT) were mixed with unsaturated polyester (UPRs) with a composition of 5% by weight and stirred using a magnetic stirrer with a rotational speed of 250 r.p.m, at a temperature of 40 o C, for 30 minutes.Composite molding uses a vacuum infusion process system.The results showed that the alkaline treatment of the fiber increased the tensile and flexural strength.Morphologically, the fiber is cleaner because it has been removed from hemicellulose, pectin and other amourphus.The addition of CNT to the composite is able to close the holes in the composite so that its strength increases.Water absorption shows that the fiber has not been alkaline, it absorbs more water. Composite number ; Carbon nanotube ; Materials science ; Composite material ; Alkali metal ; Fiber ; Fraction (chemistry) ; Volume fraction ; Chemical engineering ; Chemistry ; Chromatography ; Organic chemistry ; Engineering Carbon Nanotubes in Composites ; Fiber-reinforced polymer composites ; Tribology and Wear Analysis
Authors: M.D. REEM S.M.M. ABUELANIN KAREEM A. KAMEL | Gehad Abd El-Fatah | Mohamed Y. Zaky | Amal Zaher | Ahmed A. Farghali | Sarah I. Othman | Ahmed A. Allam | Hassan A. Rudayni | Mohamed E. M. Hassouna | Rehab Mahmoud
Source: Preprints.org (preprint, 2023-10-19)
Field: Chemistry — Electrochemistry

Innovations in Electrochemical Sensors for Lead Ion Detection: Applications in Wastewater Treatment and Cytotoxicity Assessment The requirement for developing tools capable of detecting and monitoring heavy metals (HMs) has recently taken on more significance due to worries about their toxic effect on human health and aquatic habitats. In this study, a simple electrochemical sensing carbon paste electrode (CPE) based on composite of Zinc/Iron layered double hydroxide (LDH) and polyaniline (PANI) was developed for the determination of lead ions in aquatic solutions. For this purpose, Zn-Fe LDH/PANI was prepared and characterized by Fourier transform infrared (FTIR), X ray diffraction (XRD), and scanning electron microscopy (SEM). Modified carbon electrode based Zn-Fe LDH/PANI was electrochemically characterized compared with unmodified electrode in FCN as a redox probe using cyclic voltammetry (CV). Thus, Zn-Fe LDH/PANI was utilized as sensing material for the electrochemical determination of lead ions using differential pulse voltammetry (DPV). Zn-Fe LDH/PANI/CPE show limits of detection (LOD) and quantification (LOQ) of 167.8 nM and 559.4 nM, respectively. Zn/Mg/Fe LDH was prepared using co-precipitation method and characterized by XRD, FTIR, SEM and BET, used for removal of Pb+2 ions. Removal process was investigated at different conditions as pH, metal ion concentrations, starting adsorbent dose at first and contact time. Zn/Mg/Fe LDH was evaluated as an effective adsorbent material for lead ions elimination in aquatic solutions, with capacity of adsorption 700 mg/g. The elimination of lead ions on Zn/Mg/Fe LDH fitted the pseudo first-order kinetics model and the isotherm was matched with Langmuir model. Studies revealed that the ideal removal conditions were pH = 5.0, an adsorbent mass of 0.05 g, and 20 ml of 50 ppm metal ion concentration at 60 min. The Zn-Fe LDH/PANI composite also showed potential anti-cancer properties against lung cancer cells (A549) while maintaining safety for normal lung fibroblast cells (WI-38). Collectively, advancements in electrochemical sensors offer promising solutions for lead ion detection, with wide-reaching applications in wastewater treatment and cytotoxicity assessment. These innovations have the potential to enhance environmental monitoring and public health safety. Detection limit ; Fourier transform infrared spectroscopy ; Adsorption ; Electrochemistry ; Langmuir adsorption model ; Carbon paste electrode ; Cyclic voltammetry ; Nuclear chemistry ; Materials science ; Metal ions in aqueous solution ; Hydroxide ; Differential pulse voltammetry ; Chemistry ; Inorganic chemistry ; Electrode ; Metal ; Chemical engineering ; Chromatography ; Metallurgy Electrochemical Analysis and Applications ; Analytical Chemistry and Sensors ; Conducting polymers and applications
Authors: Horacio Serna | Ariel G. Meyra | Eva G. Noya | Wojciech T. Góźdź
Source: Soft Matter (article, 2023-01-01)
Field: Materials Science — Biomaterials

Structural characterization of systems with competing interactions confined in narrow spherical shells Systems with short-range attraction and long-range repulsion can form ordered microphases in bulk and under confinement. In fact, confinement has been proven to be a good strategy to induce the formation of novel ordered microphases that might be appealing to the development of functional nanomaterials. Using Grand Canonical Monte Carlo (GCMC) simulations, we study a model colloidal system with competing interactions under confinement in narrow spherical shells at thermodynamic conditions under which the hexagonal phase is stable in bulk. We observe the formation of three parent ordered structures formed by toroidal clusters and two spherical clusters (Type I), toroidal clusters and one spherical cluster (Type II), and toroidal clusters alone (Type III), depending on the radius of the confining shell, that can often coexist with other related structures derived from these parent ones by a simple transformation, in which the system is divided into two hemispheres that are rotated with respect to each other by a given angle. We propose a general method to characterize and predict the structures obtained under confinement in spherical shells in systems able to self-assemble into a hexagonal phase in bulk. We also show that deforming the spherical shells into ellipsoidal ones affects the structure of the system in such a way that helical structures are favoured by prolate ellipsoids and toroidal structures by oblate ellipsoids. Characterization (materials science) ; Cylinder ; Spherical shell ; Materials science ; Chemical physics ; Nanotechnology ; Physics ; Shell (structure) ; Engineering ; Composite material ; Mechanical engineering Supramolecular Self-Assembly in Materials ; Block Copolymer Self-Assembly ; Advanced Materials and Mechanics
Authors: Daniel Budaszewski | Dharmendra Pratap Singh | Tomasz R. Woliński
Source: Optics Express (article, 2023-07-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Enhancement of electro-optical response of photonic crystal fibers infiltrated with ferroelectric liquid crystal doped with titanium dioxide nanoparticles Light propagation has been studied in photonic crystal fibers (PCFs) doped with W212 ferroelectric liquid crystal (FLC) composites with titanium dioxide nanoparticles (TiO<sub>2</sub> NPs) of low concentrations between 0.2 and 1 wt. % in the FLC matrix. Optical microscopy observations indicated a slight increase of transition temperature to the isotropic phase by ∼1-2°C compared to the undoped FLC sample, and the TiO<sub>2</sub> admixture was found to decrease free ionic charge impurities in the FLC, thus improving its electro-optical parameters. The switching time measurements in the PLCFs clearly indicate that TiO<sub>2</sub> NPs reduce switching times for low electric field intensity, even by 32% compared to the undoped PLCF. Materials science ; Ferroelectricity ; Titanium dioxide ; Liquid crystal ; Nanoparticle ; Impurity ; Doping ; Electric field ; Optics ; Phase (matter) ; Photonic crystal ; Optoelectronics ; Composite material ; Dielectric ; Nanotechnology Liquid Crystal Research Advancements ; Photonic Crystal and Fiber Optics ; Photonic Crystals and Applications
Authors: Krishan Bumma | Axel Huerre | Juliette Pierre | Thomas Séon
Source: Soft Matter (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Early freezing dynamics of an aqueous foam Phase-change is an essential and unavoidable process to obtain solid foam. We study experimentally the solidification dynamics of a model aqueous foam in contact with a cold substrate. The substrate temperature, the foam bubble radius and the liquid fraction are changed. We show that the freezing dynamics always starts by following a self-similar square root of time diffusive dynamics. These early dynamics are then predicted as a function of the control parameters using a 1D diffusion model and by treating our foam as a homogeneous fluid with equivalent thermophysical properties. In particular, we build a new expression for the foam conductivity. Finally, experimental and theoretical results are compared and interpreted. This study paves the way towards the understanding of the complex foam freezing dynamics at longer times, when the freezing is then coupled to water migration in the foam. Materials science ; Dynamics (music) ; Bubble ; Diffusion ; Aqueous solution ; Thermodynamics ; RADIUS ; Composite material ; Mechanics ; Chemistry ; Physics ; Physical chemistry Pickering emulsions and particle stabilization ; Heat and Mass Transfer in Porous Media ; Enhanced Oil Recovery Techniques
Authors: Eric Julien | Shmuel M. Rubinstein | Sabine Caré | Philippe Coussot
Source: Soft Matter (article, 2023-01-01)
Field: Materials Science — Surfaces, Coatings and Films

Slow spreading with a large contact angle on hygroscopic materials Water transfer in wood plays a major role during the life time of timber structures but the physics of the various processes involved, such as wetting and imbibition, is not fully understood. Here we show that the angle of contact of a water drop placed in contact with an air dry wood surface is initially larger than 90°, then the drop slowly spreads over the surface, while the apparent (macroscopic) contact angle decreases down to a few tens of degrees. We show that similar results are obtained with a model material, <i>i.e.</i> hydrogel, as soon as a perturbation is induced onto the line of contact. We demonstrate that for the gel the initial large apparent contact angle results from a strong deformation of the gel in a thin softened region below the line of contact resulting from the fast diffusion of water and swelling of this region. This phenomenon ensures a real (local) contact angle close to zero. The spreading then results from the progressive diffusion of water at farther distance and successive perturbations of the line of contact when the drop enters in contact with small liquid droplets dispersed along the surface (residues of the chemical reaction during gel preparation). It is suggested that a similar effect occurs for the water drop over a wood surface and explains the large initial contact angle and slow spreading: the line of contact is initially pinned thanks to a wood surface deformation resulting from the wood surface swelling due to water absorption, thus leading to a large contact angle; it will then unpin when the local conditions have changed as a result of water diffusion at further distance, allowing for a small displacement up to the next pinning point and so on. Contact angle ; Drop (telecommunication) ; Materials science ; Volume (thermodynamics) ; Composite material ; Mechanics ; Thermodynamics ; Physics Surface Modification and Superhydrophobicity ; Fluid Dynamics and Heat Transfer ; Experimental and Theoretical Physics Studies
Authors: Aurélien Riot | François Virot | Damien Connétable
Source: Journal of the American Ceramic Society (article, 2023-04-02)
Field: Materials Science — Materials Chemistry

Solubility and diffusivity of hydrogen and its isotopes in the BeO system Abstract This work revisits hydrogen insertion in the wurtzite beryllium oxide in order to fill the gap in scientific knowledge regarding the diffusion coefficients of the different chemical states of hydrogen (neutral, charged, or molecular). Both first‐principle and macroscopic models were used to this end. In the former, two exchange‐correlation functionals (PBE and SCAN) were used to compute the properties of interest and accuracy was then discussed. Regarding the behavior of interstitial insertion of hydrogen, this work is slightly different from previous works; hydrogen was mainly found in the form of charged H − or H + ions, depending on experimental conditions. In regard to diffusivity properties, a complex migration pathway was found for hydrogen cation. Finally, the present study succeeded in producing a reliable set of diffusion coefficients for neutral, charged, and molecular hydrogen. Hydrogen ; Beryllium oxide ; Thermal diffusivity ; Diffusion ; Solubility ; Work (physics) ; Oxide ; Chemistry ; Ion ; Beryllium ; Chemical physics ; Thermodynamics ; Physical chemistry ; Materials science ; Computational chemistry ; Physics ; Organic chemistry Hydrogen Storage and Materials ; Molten salt chemistry and electrochemical processes ; Advanced Chemical Physics Studies
Authors: Khasan Abdukayumov | Martin Mičica | Fatima Ibrahim | Vergnaud, C. | Marty, A. | J.‐Y. Veuillen | Pierre Mallet | de Moraes, I. Gomes | Isabelle Gomes de Moraes | Wright, A. | Tignon, J. | Mangeney, J. | Ouerghi, A. | J. Tignon | J. Mangeney | Bonell, F. | V. Renard | Chshiev, M. | George, J. -M. | Jaffrès, H. | Dhillon, S. | Jamet, M.
Source: arXiv (Cornell University) (preprint, 2023-05-11)
Field: Materials Science — Materials Chemistry

Atomic-layer controlled THz Spintronic emission from Epitaxially grown Two dimensional PtSe$_2$/ferromagnet heterostructures Terahertz (THz) Spintronic emitters based on ferromagnetic/metal junctions have become an important technology for the THz range, offering powerful and ultra-large spectral bandwidths. These developments have driven recent investigations of two-dimensional (2D) materials for new THz spintronic concepts. 2D materials, such as transition metal dichalcogenides (TMDs), are ideal platforms for SCC as they possess strong spin-orbit coupling (SOC) and reduced crystal symmetries. Moreover, SCC and the resulting THz emission can be tuned with the number of layers, electric field or strain. Here, epitaxially grown 1T-PtSe$_2$ and sputtered Ferromagnet (FM) heterostructures are presented as a novel THz emitter where the 1T crystal symmetry and strong SOC favor SCC. High quality of as-grown PtSe$_2$ layers is demonstrated and further FM deposition leaves the PtSe$_2$ unaffected, as evidenced with extensive characterization. Through this atomic growth control, the unique thickness dependent electronic structure of PtSe$_2$ allows the control of the THz emission by SCC. Indeed, we demonstrate the transition from the inverse Rashba-Edelstein effect in one monolayer to the inverse spin Hall effect in multilayers. This band structure flexibility makes PtSe$_2$ an ideal candidate as a THz spintronic 2D material and to explore the underlying mechanisms and engineering of the SCC for THz emission. Spintronics ; Heterojunction ; Terahertz radiation ; Materials science ; Ferromagnetism ; Condensed matter physics ; Optoelectronics ; Epitaxy ; Nanotechnology ; Physics ; Layer (electronics) 2D Materials and Applications
Authors: Dallacoasta Iyayosa Andrea | Abdullahi Abdulsalam | Alechenu Audu Aboje | O.S. Azeez
Source: International Research Journal of Pure and Applied Chemistry (article, 2023-12-29)
Field: Chemistry — Organic Chemistry

Application of Activated Rice Husk for Adsorptive Bleaching of Groundnut Oil: Kinetic, Equilibrium and Thermodynamic Study Kinetic, equilibrium and, thermodynamic studies of the bleaching of crude groundnut oil at optimized conditions were carried out using activated rice husk as an adsorbent for the bleaching process. The efficiency of bleaching was estimated by measuring the absorbance using a double- beam spectrophotometer at a wavelength of 450nm. The effects of adsorbent dosage, bleaching temperature and, contact time on the bleaching efficiency were studied. A directly proportional relationship was found between dosage and contact time and the bleaching efficiency while a bell curve was discovered for temperature increase. The surface area of the rice husk increased from 150.32 to 1450.32 m2/g while the pore volume decreased from 0.15524 to 0.12844 cm3/g after activation which was determined via a Brunauer-Emmet-Teller (BET) analysis and the results further validated by the Scanning Electron Microscopy (SEM) images obtained. The kinetic data of the bleaching process were best described by the pseudo-second order kinetic model while the equilibrium adsorption isotherm analysis showed that the results from the Temkin isotherm were the most significant. The thermodynamic study revealed that the adsorptive bleaching process is feasible, spontaneous and, exothermic with a decrease in entropy. The enthalpy value also showed that the adsorption process is predominantly physisorption. This study has revealed that an effective adsorbent can be produced from rice husks under optimized process conditions. Chemistry ; Physisorption ; Adsorption ; Husk ; Enthalpy ; Absorbance ; Langmuir adsorption model ; Exothermic reaction ; Nuclear chemistry ; Analytical Chemistry (journal) ; Thermodynamics ; Chromatography ; Organic chemistry ; Botany Edible Oils Quality and Analysis
Authors: Dmitrii Moldarev | Max Wolff | Daniel Primetzhofer
Source: The Journal of Physical Chemistry C (article, 2023-12-14)
Field: Materials Science — Materials Chemistry

Modification of the Photochromic Properties of Oxygen-Containing Yttrium Hydride by Irradiation with keV and MeV Ions The effect of irradiation using energetic ions on the optical properties of photochromic YHO was studied. Films were exposed to different fluences (Φ); projectiles and their primary energies were chosen such that a wide range of ratios between energies transferred to electron and nuclear systems is covered. Structural modifications are found to induce a decrease in transmittance, magnitude of the photochromic response, and the bleaching kinetics. For irradiation with 330 keV Ne+, X-ray diffraction revealed changes in the microstructure such as grain growth for higher fluences explaining the observed persistency of changes in optical properties after irradiation. On the other hand, the degradation of photochromic properties was found to be reversible for Φ = 1 × 1015 cm–2. The results indicate that grain boundary diffusion is necessary for the photochromic reaction. Photochromism ; Irradiation ; Materials science ; Ion ; Photochemistry ; Yttrium ; Oxygen ; Grain boundary ; Microstructure ; Diffusion ; Kinetics ; Analytical Chemistry (journal) ; Chemistry ; Composite material ; Nuclear physics ; Metallurgy ; Physics ; Oxide Nuclear Materials and Properties ; Luminescence Properties of Advanced Materials ; Advanced Semiconductor Detectors and Materials
Authors: Cyril E. Nworie | Dominic O. Onukwuli | Edwin Ikezue | L.O. Ekebafe
Source: Proceedings of the Nigerian Academy of Science (article, 2023-01-20)
Field: Materials Science — Materials Chemistry

Effect of adsorption variables on the removal of Cadmium ions from wastewater using activated periwinkle shell from Okada, Edo State This paper details the effect of adsorption variables on the removal of cadmium ions from wastewater using activated periwinkle shell. The periwinkle shells were carbonized for 1.5h for 900oC, and activated using HNO3 and calcium chloride solution. The textural characteristic of the adsorbent was determined using BET surface area analysis methods, structural characterizations of the activated carbon from the periwinkle shells were performed using FTIR, SEM, and EDX. Three different concentrations of cadmium ions solution were prepared as 10mg/l, 30mg/l, 50mg/l, 80mlg/l and 100mg/l from the stock solution. The batch mode adsorption experiment of cadmium ion onto activated periwinkle shell was carried out. The effects of time of contact, pH, initial concentration, adsorbent dose, particle sizes and temperature were investigated. The result indicates that activated periwinkle shell exhibit good sorption capacity with a large surface area of 574.50m2/g and mesoporosity of 71.42%. The sorption capacity were 67.28m2/g for Cd(II) ions. The equilibrium was attained after 70mins with the particle size of 212μm. The results indicate that the pH for maximum removal of cadmium (II) ions is 6.0. Adsorption ; Sorption ; Activated carbon ; Cadmium ; Carbonization ; Particle size ; Wastewater ; Chemistry ; Biosorption ; Nuclear chemistry ; BET theory ; Ion ; Chemical engineering ; Materials science ; Chromatography ; Environmental engineering ; Organic chemistry ; Environmental science ; Physical chemistry Graphite, nuclear technology, radiation studies ; Environmental Engineering and Cultural Studies
Authors: Boyuan Yu | Heyi Liang | Paul F. Nealey | Matthew Tirrell | Artem M. Rumyantsev | Juan Pablo
Source: PubMed (preprint, 2023-06-01)
Field: Materials Science — Surfaces, Coatings and Films

Structure and Dynamics of Hybrid Colloid-Polyelectrolyte Coacervates: Insights from Molecular Simulations Electrostatic interactions in polymeric systems are responsible for a wide range of liquid-liquid phase transitions that are of importance for biology and materials science. Such transitions are referred to as complex coacervation, and recent studies have sought to understand the underlying physics and chemistry. Most theoretical and simulation efforts to date have focused on oppositely charged linear polyelectrolytes, which adopt nearly ideal-coil conformations in the condensed phase. However, when one of the coacervate components is a globular protein, a better model of complexation should replace one of the species with a spherical charged particle or colloid. In this work, we perform coarse-grained simulations of colloid-polyelectrolyte coacervation using a spherical model for the colloid. Simulation results indicate that the electroneutral cell of the resulting (hybrid) coacervates consists of a polyelectrolyte layer adsorbed on the colloid. Power laws for the structure and the density of the condensed phase, which are extracted from simulations, are found to be consistent with the adsorption-based scaling theory of hybrid coacervation. The coacervates remain amorphous (disordered) at a moderate colloid charge, <i>Q</i>, while an intra-coacervate colloidal crystal is formed above a certain threshold, at <i>Q</i> > <i>Q</i>*. In the disordered coacervate, if <i>Q</i> is sufficiently low, colloids diffuse as neutral nonsticky nanoparticles in the semidilute polymer solution. For higher <i>Q</i>, adsorption is strong and colloids become effectively sticky. Our findings are relevant for the coacervation of polyelectrolytes with proteins, spherical micelles of ionic surfactants, and solid organic or inorganic nanoparticles. Coacervate ; Polyelectrolyte ; Colloid ; Chemical physics ; Phase (matter) ; Chemistry ; Nanoparticle ; Ionic strength ; Adsorption ; Materials science ; Nanotechnology ; Polymer ; Physical chemistry ; Chromatography ; Aqueous solution ; Organic chemistry Polymer Surface Interaction Studies ; Blood properties and coagulation ; Surfactants and Colloidal Systems