jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Prerit Roshan
Source: International Journal of Research in Science and Technology (article, 2023-01-01)
Field: Chemistry — Spectroscopy

Study of Rate of Diffusion of Liquids and Factors Affecting it DiffusionDiffusion is a physical process that refers to the spontaneous movement of particles, atoms, or molecules from an area of higher concentration to an area of lower concentration.It is a fundamental concept in various scientific fields, including physics, chemistry, biology, and engineering.In the context of gases, diffusion occurs as gas molecules move and spread out to occupy the available space.This movement is driven by the random thermal motion of particles.Over time, the molecules disperse and become evenly distributed throughout the system.For example, when a bottle of perfume is opened in one corner of a room, the fragrance eventually spreads throughout the entire room due to diffusion. Diffusion ; Materials science ; Chemical engineering ; Chemistry ; Thermodynamics ; Engineering ; Physics Adsorption, diffusion, and thermodynamic properties of materials
Authors: Ahmet Gürses | Arvin Sehhatigdiri | Demet Yılmaz | Elif Şahin
Source: Preprints.org (preprint, 2023-12-05)
Field: Chemistry — Inorganic Chemistry

Adsorption of Uranium (VI) from Aqueous Solution Using Melamine Formaldehyde Organo Clay Nanocomposite Foam as a Novel Adsorbent Abstract: Uranium is a toxic radioactive element and is usually found in the environment in hexavalent form. It has become a necessity to remove uranium, which can enter the environment in excessive amounts through nuclear industrial activities, from access waters. Melamine formaldehyde organo clay nano composite foam (MFCNCF) was prepared as a novel adsorbent by hardening with thermal treatment. Structural, crystallographic textural and surface morphological characterization of the prepared adsorbent was made by FTIR and XRD spectroscopic and SEM and HRTEM microscopic techniques. This study aims to investigate the adsorption of U(VI) from aqueous solution by MF organo clay nanocomposite and its dependence on various variables such as initial uranium concentration, adsorption time, adsorbent dosage, initial pH, and temperature. Additionally, adsorption isotherm analysis and adsorption kinetics and thermodynamics were also examined. For this purpose, the batch adsorption experiments were carried out and the equilibrium concentration of U(VI) in the aqueous solution was measured with a UV-Vis spectrophotometer at a wavelength of 433 nm, which corresponds to its maximum absorptivity. The results regarding adsorption kinetics show that 30 min is sufficient to reach adsorption equilibrium and the data show a high fit to the pseudo-second-order kinetic model. Isotherm analysis also revealed a high fit of the data to the Type III isotherm and the Halsey model. Based on this fit, an adsorption mechanism involving two regions (electrostatic and complex formation) was proposed for the current adsorption system. The adsorption isosteric enthalpy and entropy values for the first and second regions are 3.65 and -51.02kJ/mol and 1.77 and -167.28J/mol, respectively. It was found in kmol. Experimental results showed that the prepared nanocomposite foam adsorbent is an effective and potential alternative for the effective removal of U(VI) from aqueous solutions. Adsorption ; Aqueous solution ; Uranium ; Enthalpy ; Nanocomposite ; Chemistry ; Mesoporous material ; Langmuir adsorption model ; Chemical engineering ; Materials science ; Nuclear chemistry ; Physical chemistry ; Organic chemistry ; Composite material ; Thermodynamics ; Catalysis Radioactive element chemistry and processing ; Extraction and Separation Processes
Authors: Asmaa Ahmed | Safaa El‐Nahas | Mohammed Ezzeldien
Source: Aswan University Journal of Environmental Studies (article, 2023-02-01)
Field: Chemistry — Analytical Chemistry

Purification of drinking water from dissolved Bisphenol A (BPA) using zinc oxide nanoparticles The goal of this research is to study the potential of ZnO nanoparticles as an alternative material for the removal of bisphenol A (BPA) that can be used in ceramic membrane. To safeguard water from organic pollutants like BPA, one of the SDGs' objectives was to ensure access to clean drinking water (goal 6). This research has been studied of various factors for removal of BPA, including contact time, pH, temperature, initial BPA levels, and ZnO NPs dosage. The removal of BPA onto ZnO NPs matched well with the Langmuir, Freundlich, and Temkin isotherm models. The maximum removal efficiency under optimum conditions was achieved 85%. The kinetic data fitted well the pseudo-second order model than other models. The phenomenon for removal of BPA was a spontaneous process and showed the endothermic nature. Thermodynamic, kinetics and isotherm data indicate that more than one mechanism was applied for removal of BPA from water. Bisphenol A ; Zinc ; Nanoparticle ; Environmental chemistry ; Chemistry ; Nuclear chemistry ; Chemical engineering ; Organic chemistry ; Engineering Petroleum Processing and Analysis
Authors: Caroline J. Aschendorf | Mawuli Degbevi | Keaton V. Prather | Emily Y. Tsui
Source: ChemRxiv (preprint, 2023-09-06)
Field: Materials Science — Materials Chemistry

EPR Spin Trapping of Nucleophilic and Radical Reactions at Colloidal Metal Chalcogenide Quantum Dot Surfaces The possible participation of colloidal semiconductor nanocrystal quantum dot (QD) surfaces in QD-mediated photocatalytic reactions is an important factor that distinguishes QDs from other photosensitizers (e.g. noble metal complexes or organic dyes). Here, we probe nucleophilic and radical reactivity of surface sulfides and selenides of metal chalcogenide (CdSe, CdS, ZnSe, and PbS) QDs using various chemical reactions and NMR spectroscopy. Additionally, the high sensitivity of EPR spectroscopy is adapted to study these surface-centered reactions through the use of spin traps like 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) under photoexcitation and thermal conditions. We demonstrate that DMPO likely adds to CdSe QD surfaces under thermal conditions by a nucleophilic mechanism in which the surface chalcogenides add to the double bond, followed by further oxidation of the surface-bound product. In contrast, CdS QDs more readily form surface sulfur-centered radicals that can perform reactions including alkene isomerization. These results indicate that QD surfaces should be an important consideration for the design of photocatalysis beyond simply tuning QD semiconductor band gaps. Photochemistry ; Chemistry ; Quantum dot ; Photocatalysis ; Reactivity (psychology) ; Electron paramagnetic resonance ; Nucleophile ; Nanocrystal ; Photoexcitation ; Spectroscopy ; Spin trapping ; Chalcogenide ; Metal ; Radical ; Materials science ; Nanotechnology ; Organic chemistry ; Catalysis ; Excited state Quantum Dots Synthesis And Properties ; Chalcogenide Semiconductor Thin Films ; Electrocatalysts for Energy Conversion
Authors: Jun Qian | Jiajia Su | Weihuan Zeng | Yue Wang | Yingyuan Hu | Guoyin Kai
Source: Molecules (article, 2023-07-06)
Field: Materials Science — Materials Chemistry

Comparison of Salvianolic Acid A Adsorption by Phenylboronic-Acid-Functionalized Montmorillonites with Different Intercalators Due to its success in treating cardio-cerebrovascular illnesses, salvianolic acid A (SAA) from <i>Salvia miltiorrhiza</i> is of major importance for effective acquisition. For the adsorption of salvianolic acid, cationic polyelectrolytes, and amino-terminated silane intercalated with phenylboronic-acid-functionalized montmorillonites, known as phenylboronic-acid-functionalized montmorillonites with PEI (PMP) and phenylboronic-acid-functionalized montmorillonites with KH550 (PMK), respectively, were produced. In this paper, detailed comparisons of the SAA adsorption performance and morphology of two adsorbents were performed. PMP showed a higher adsorption efficiency (>88%) over a wide pH range. PMK showed less pH-dependent SAA adsorption with a faster adsorption kinetic fitting in a pseudo-second-order model. For both PMP and PMK, the SAA adsorption processes were endothermic. Additionally, it was clearer how temperature affected PMP adsorption. PMK has a higher adsorption selectivity. This study demonstrates how the type of intercalator can be seen to have an impact on adsorption behavior through various structural variations and offers an alternative suggestion for establishing a dependable method for the synthesis of functional montmorillonite from the intercalator's perspective. Adsorption ; Phenylboronic acid ; Cationic polymerization ; Chemistry ; Intercalation (chemistry) ; Montmorillonite ; Selective adsorption ; Selectivity ; Polymer chemistry ; Inorganic chemistry ; Organic chemistry ; Catalysis Mesoporous Materials and Catalysis ; Clay minerals and soil interactions ; NMR spectroscopy and applications
Authors: R. Abirami | S. P. Sangeetha | R. Divahar
Source: International Journal of Civil Engineering (article, 2023-06-30)
Field: Materials Science — Polymers and Plastics

Comparative Analysis on Reinforced Concrete Beam-Column Joint with Sisal Fiber Under Cyclic Loading The most critical failure regions are the joints between beams and columns. Under dynamic loads, the bonding of the rebars in the concrete will be severely stressed and fail. In addition to damaging the column loading paths, the collapse of the joint point may also affect the structure's overall ductility and capacity to dissipate energy. This study examined the relationship between natural fiber in beam-column joints by adding 0.5% to 1.5% with an increment of 0.25% of sisal fiber to reinforced concrete. Ductile detailing was done as per the IS 13920-2016. The analysis is carried out using the finite element software ANSYS workbench, and it is developed considering the effects of cyclic loading. The structural behaviour under cyclic loading was analyzed using Finite Element Method (FEM) analysis, including maximum load and displacement values compared with experimental values. A Comparison of FEM analysis and experimental values showed that the 1.25 % addition of Sisal fiber in reinforced concrete performs better in the joint between a beam and a column to withstand lateral and seismic loads on the structures. Structural engineering ; Finite element method ; Ductility (Earth science) ; Joint (building) ; Materials science ; Beam (structure) ; Displacement (psychology) ; Fiber ; Composite material ; Engineering Natural Fiber Reinforced Composites ; Innovative concrete reinforcement materials ; Structural Behavior of Reinforced Concrete
Authors: Juan Matos | Claudia Patricia Amézquita-Marroquín | Johan D Lozano | Jhon Zapata‐Rivera | Liliana Giraldo | Po S. Poon | Juan Carlos Moreno‐Piraján
Source: Preprints.org (preprint, 2023-06-14)
Field: Materials Science — Materials Chemistry

Experimental and Theoretical Estimations of Atrazine´s Adsorption on Mangosteen Peel-derived Nanoporous Carbons Nanoporous carbons were prepared by chemical and physical activation from mangosteen peel-derived chars. The removal of atrazine was studied due to the bifunctionality of the N-groups. Pseudo-first-order, pseudo-second order and intraparticle pore diffusion kinetic models were analyzed. Adsorption isotherms were also analyzed according to Langmuir and Freundlich models. Results obtained were compared against two commercial activated carbons with comparable surface chemistry and porosimetry. The highest uptake was found for the carbons with higher content of basic surface groups. The role of the oxygen-containing groups on the removal of atrazine was estimated experimentally by the surface density. Results were compared with the adsorption energy of atrazine theoretically estimated on pristine and functionalized graphene with different oxygen-groups using periodic DFT methods. The energy of adsorption follows the same trend observed experimentally, namely the more basic the pH the more favored is the adsorption of atrazine. Micropores play an important role in the uptake of atrazine at low concentration but the presence of mesoporous is also required to inhibit the pore mass diffusion limitations. The present work contributes to the understanding of the interactions between triazine-based pollutants and the surface functional groups on nanoporous carbons in the liquid-solid interface. Adsorption ; Atrazine ; Nanoporous ; Langmuir ; Chemistry ; Freundlich equation ; Chemical engineering ; Diffusion ; Activated carbon ; Organic chemistry ; Thermodynamics Covalent Organic Framework Applications ; Adsorption and biosorption for pollutant removal ; Pesticide and Herbicide Environmental Studies
Authors: Iaroslav Babenko | Nils Kröger | Benjamin M. Friedrich
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-07-03)
Field: Materials Science — Biomaterials

Mechanism of branching morphogenesis inspired by diatom silica formation Abstract The silica-based cell walls of diatoms are prime examples of genetically controlled, species-specific mineral architectures. The physical principles underlying morphogenesis of their hierarchically structured silica patterns are not understood, yet such insight could indicate novel routes towards synthesizing functional inorganic materials. Recent advances in imaging nascent diatom silica allow rationalizing possible mechanisms of their pattern formation. Here, we combine theory and experiments on the model diatom Thalassiosira pseudonana to put forward a minimal model of branched rib patterns – a fundamental feature of the silica cell wall. We quantitatively recapitulate the time-course of rib pattern morphogenesis by accounting for silica biochemistry with autocatalytic formation of diffusible silica precursors followed by conversion into solid silica. We propose that silica deposition releases an inhibitor that slows down up-stream precursor conversion, thereby implementing a self-replicating reaction-diffusion system featuring a non-classical Turing mechanism. The proposed mechanism highlights the role of geometrical cues for guided self-organization, rationalizing the instructive role for the single initial pattern seed known as primary silicification site. The mechanism of branching morphogenesis that we characterize here is possibly generic and may apply also in other biological systems. Significance statement The formation of minerals by living organisms is a widespread biological phenomenon occurring throughout the evolutionary tree-of-life. The silica-based cell walls of diatom microalgae are impressive examples featuring intricate architectures and outstanding materials properties that still defy their reconstitution in vitro . Here, we developed a minimal mathematical model that explains the formation of branched patterns of silica ribs, providing unprecedented understanding of basic physico-chemical processes capable of guiding silica morphogenesis in diatoms. The generic mechanism of branching morphogenesis identified here could provide recipes for bottom-up synthesis of mineral-nanowire networks for technological applications. Moreover, similar mechanisms may apply in the biological morphogenesis of other branched structures, like corals, bacterial colonies, tracheal networks, fungal plexuses, or the vascular system. Thalassiosira pseudonana ; Morphogenesis ; Diatom ; Branching (polymer chemistry) ; Mechanism (biology) ; Frustule ; Nanotechnology ; Materials science ; Chemistry ; Biology ; Ecology ; Organic chemistry ; Physics Diatoms and Algae Research ; Protist diversity and phylogeny ; Paleontology and Stratigraphy of Fossils
Authors: Alexander P. Hawkins | Andrea Zachariou | Paul Collier | Russell F. Howe | David Lennon | Stewart F. Parker
Source: Johnson Matthey Technology Review (article, 2023-10-04)
Field: Chemistry — Inorganic Chemistry

Inelastic Neutron Scattering Studies of Propene and 1-Octene Oligomerisation in H-ZSM-5 Neutron scattering methods such as quasielastic neutron scattering (QENS) and inelastic neutron scattering (INS) have been used to study the reactivity of propene and 1-octene over the acid zeolite catalyst H-ZSM-5. The high activity of the catalyst causes the alkenes to form linear oligomers below room temperature. INS has shown that the reaction proceeds through a hydrogen-bonded intermediate. Studies using propane as an inert analogue for propene have found that the adsorbed C3 molecules spend much of their time undergoing short jumps within the pore channels of the zeolite. Hydrothermal dealumination plays an important role in determining the activity of zeolite catalysts. Dealumination was found to delay the onset of catalytic activity for oligomerisation to higher temperatures and increase the mobility of hydrocarbons within the zeolite, both due to reduced acid-hydrocarbon interactions. Propene ; Octene ; Materials science ; Neutron scattering ; Inelastic neutron scattering ; Neutron ; Nuclear physics ; Chemistry ; Physics ; Composite material ; Catalysis ; Organic chemistry ; Polymer ; Copolymer Zeolite Catalysis and Synthesis ; Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography
Authors: Afranur Pendar | Ceyda Duyar | Yunus Zorlu | Derya Davarcı
Source: Research Square (preprint, 2023-08-22)
Field: Chemistry — Inorganic Chemistry

Ag(I) and Hg(II) coordination polymers decorated from fully benzimidazole substituted cyclotriphosphazene ligand and adsorption behaviour against Methylene Blue Abstract Herein, we reported new two coordination polymers, {[Ag(L)](CH 3 PhSO 3 )](CH 3 CN) 4 } n ( cp-1 ) and {[Hg(L)](Cl 2 )](CH 3 CN) 2 } n (cp-2) , were synthesized from hexapodal benzimidazole substituted cyclotriphosphazene, ( L ). L was characterised by 1 H NMR, 31 P NMR and mass analysis. Structure of each isolated compounds were determined by single crystal X-ray crystallography. In cp-1 , L has a κ 3 N coordination mode by connecting three Ag(I) ions to constitute a 2D coordination framework whereas the ligand in cp-2 displays κ 2 N coordination mode via linking four Hg(II) ions together to create a 1D coordination polymer. Topologically, cp-1 has a 3-connected uninodal net having the point symbol {4.8 2 }. Dye adsorption studies of coordination polymers was performed out using UV-Vis. absorption spectroscopy. Adsorption experiments show that cp-1 and cp-2 removes the cationic methylene blue (MB) from water but shows no adsorption behaviour toward the anionic methyl orange (MO) and tartrazine (E102). Benzimidazole ; Cationic polymerization ; Chemistry ; Ligand (biochemistry) ; Adsorption ; Crystallography ; Coordination polymer ; Methylene blue ; Coordination complex ; Methyl orange ; Polymer ; Ion ; Methylene ; Crystal structure ; Polymer chemistry ; Medicinal chemistry ; Physical chemistry ; Organic chemistry ; Photocatalysis Metal-Organic Frameworks: Synthesis and Applications ; Magnetism in coordination complexes ; Metal complexes synthesis and properties
Authors: Lin Zhu | Wenjing Zheng | Hongbo Xie | Kan Zhang
Source: Research Square (preprint, 2023-02-08)
Field: Materials Science — Surfaces, Coatings and Films

Biowaste derived sustainable carbon aerogels/polyvinylidene fluoride composites for effective removal of organic pollutants/oils Polyvinylidene fluoride ; Pollutant ; Materials science ; Composite material ; Fluoride ; Carbon fibers ; Chemical engineering ; Waste management ; Chemistry ; Composite number ; Organic chemistry ; Inorganic chemistry ; Polymer Surface Modification and Superhydrophobicity
Authors: Lekaa k. abdul karem Karem | Angham Tariq Ali | Ewies F. Ewies
Source: Ibn AL- Haitham Journal For Pure and Applied Science (article, 2023-10-20)
Field: Materials Science — Materials Chemistry

Biosynthesis, Characterization, Adsorption and Antimicrobial studies of zirconium oxide Nanoparticles Using Punica Granatum Extract In this study we using zirconium sulfate, Punica granatum plant extract, and an alkaline medium, to created ZrO2 nanoparticles. They were then characterized using a variety of techniques, including FT-IR, UV-visible, atomic force microscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Debye-Scherrer equation was used to calculate the crystal size in X-ray diffraction and found to be 27.82 nm. The particle size of ZrO2 nanoparticles was determined using atomic force microscopy, scanning electron microscopes, and transmission electron microscopy. Utilizing ZrO2 NPs, the metal ions M (II) = Co, Ni, and Cu were successfully adsorbed, proving that the three metal ions could be removed from the water at the same time. Over the time frame and under the circumstances, Ni(II) has the highest rate of adsorption. Co, Ni, and Cu ions had removal efficiencies of 32.79%, 75.00%, and 30.20%, respectively. Three concentrations of the ZrO2 nanoparticles were tested against two types of bacteria, Escherichia coli and staphylococcus, and one type of fungus, Candida, in various concentrations of (25, 50, and 75) mg/L. The outcomes were contrasted with those attained using the medications Amoxicillin and Metronidazole. Scanning electron microscope ; Transmission electron microscopy ; Nuclear chemistry ; Adsorption ; Nanoparticle ; Analytical Chemistry (journal) ; Materials science ; Metal ions in aqueous solution ; Chemistry ; Inorganic chemistry ; Metal ; Nanotechnology ; Chromatography ; Organic chemistry Nanoparticles: synthesis and applications ; Pigment Synthesis and Properties
Authors: Egah GO | Rufus Sha’Ato | AU Itodo | Wuana RA
Source: International Journal of Scientific Research Updates (article, 2023-09-12)
Field: Chemistry — Analytical Chemistry

Sorption of tartrazine dye from aqueous solution using activated carbon prepared from Cocos nucifera husk Sorption of Tartrazine dye from aqueous solution using activated carbon prepared from Cocos nucifera (coconut) husk was investigated in this work. The coconut shell was first carbonized at 700°C in a muffle furnace and activated with NaOH for one hour. The activated carbon (AC) was applied to remove tartrazine from aqueous solutions over a concentration range of 50-250 mg/L respectively. Adsorbent features were determined using X-ray fluorescence (XRF), Fourier transformed infrared spectroscopy (FTIR), Scanning electron micrograph (SEM) techniques. Based on this investigation, adsorption of Tartrazine dye is strongly affected by initial solution pH, initial solution concentrations, dosage, and time of contact which favours the removal. Except for temperature which was found to decrease with increase temperature for AC, while adsorption capacity of Tartrazine was found to decrease with increase in adsorbent dosage for AC. The optimum pH for adsorption Tartrazine removal was found to be 3. The experimental data of Tartrazine was found to fit the linearized Langmuir isotherm better than the Freundlich isotherm and D-R model indicating a monolayer adsorption. On effect of initial solution concentration, adsorption capacity of Tartrazine was found to increase with increase in concentration for AC. Kinetic data fitted more into pseudo second order model than first order and intra particle diffusion model, suggesting that chemisorption dominate the rate limiting step. The calculated thermodynamic parameters – Gibbs free energy, enthalpy change and entropy change indicated that adsorption of Tartrazine was endothermic and not spontaneous meaning the chemisorption dominates physisorption. Tartrazine ; Adsorption ; Chemistry ; Aqueous solution ; Activated carbon ; Physisorption ; Freundlich equation ; Chemisorption ; Enthalpy ; Fourier transform infrared spectroscopy ; Sorption ; Langmuir ; Langmuir adsorption model ; Nuclear chemistry ; Analytical Chemistry (journal) ; Chemical engineering ; Chromatography ; Organic chemistry ; Thermodynamics Dye analysis and toxicity ; Electrochemical sensors and biosensors ; Advanced Nanomaterials in Catalysis