jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Viktoria Milkova
Source: Polymers (article, 2023-09-14)
Field: Materials Science — Materials Chemistry

Polysaccharide/Carbon Quantum Dots Composite Film on Model Colloidal Particles—An Electro-Optical Study Negatively charged carbon dots (Cdots) were successfully impregnated into chitosan/alginate film formed on model colloidal particles as a result of the attractive interactions with the chitosan molecules. The electrical properties of the produced films were studied by electrokinetic spectroscopy. In this study, the electric light scattering method was applied for first the time for the investigation of suspensions of carbon-based structures. The electro-optical behavior for the suspension of polymer-coated particles showed that the electric polarizability of the particle-covered layer from alginate was significantly higher compared to that of the layer from chitosan due to the higher charge density of alginate. The presence of a low concentration of Cdots in the film results in partial charge screening. It was confirmed that the polarizability of counterions with lower mobility along the adsorbed polyion chains was responsible for the registered electro-optical effect from the suspension of polymer-coated particles and that the participation of diffuse H<sup>+</sup> counterions of Cdots in the creation of the electro-optical effect was negligible. The observed oscillation behavior in the evolution of the film thickness was interpreted through the participation of compensatory effects due to the additional adsorption/desorption of polyelectrolyte complexes from the film surface. The concentration of Cdots in the film was determined, and the loaded amount was ca. 6.6 µg/mL per layer. Materials science ; Polarizability ; Adsorption ; Electrokinetic phenomena ; Suspension (topology) ; Particle (ecology) ; Polymer ; Polyelectrolyte ; Chemical engineering ; Chitosan ; Surface charge ; Counterion ; Colloid ; Desorption ; Composite number ; Chemical physics ; Electric field ; Light scattering ; Analytical Chemistry (journal) ; Scattering ; Nanotechnology ; Molecule ; Composite material ; Ion ; Chemistry ; Chromatography ; Optics ; Organic chemistry ; Physical chemistry Carbon and Quantum Dots Applications ; Electrostatics and Colloid Interactions ; Electrochemical sensors and biosensors
Authors: Sakuri Sakuri | Bambang Sugiantoro | M. Agus Shidiq | Reza Azizul Nasa Al Hakim
Source: Jurnal Rekayasa Mesin (article, 2023-08-15)
Field: Materials Science — Polymers and Plastics

INVESTIGATION INTERFACIAL SHEAR STRENGTH AND MECHANICAL PROPERTIS OF ALKALI TREATED HONEY PINEAPPLE FIBER/ MICROCRYSTALLINE CELLULOSE COMPOSITE The research objective was investigate the effect of alkali treatment on thermal stability, interfacial shear strength, mechanical properties and waterabsorption in composite of honey pineapple fiber (HPF). HPF was not given and treated by soaking in a mixture of 6% wt sodium hydroxide. Mixing between Unsaturated Polyester (UPRs) and Microcrystalline Cellulose (MCC) applied the Taguchi test with 5% MCC, 250 RPm, 40 oC temperature, and 30 minutes. The composites were mold using the vacuum infusion method and curing at 60 o C for 120 minutes. Interfacial shear strength test showed 9 hours of immersion, gave strength of 3.49 MPa, an increase of 37.39%. Tensile strength increased by 30.4%,the flexural strength of the composite increased by 51.08%. The results of the SEM test showed the fiber untreated was still smooth and there were several interface gaps. The water absorption test showed that the untreated fiber had a higher absorption rate. Materials science ; Composite material ; Flexural strength ; Sodium hydroxide ; Composite number ; Ultimate tensile strength ; Microcrystalline cellulose ; Absorption of water ; Izod impact strength test ; Fiber ; Curing (chemistry) ; Cellulose ; Chemistry Natural Fiber Reinforced Composites ; Textile materials and evaluations ; Advanced Cellulose Research Studies
Authors: S. Ukachuku | D. E. Amaebi | C. I. Dike
Source: Journal of applied science and environmental management (article, 2023-02-28)
Field: Chemistry — Organic Chemistry

Adsorption of Methyl Orange and Amoxicillin from Water using Metal-organic Framework Prepared from Solvothermal Mixing of Zn ions and 1,4-Benzenedicarboxylic Acid Moieties In this study, we determined the capacity of metal organic framework, which we prepared by the solvothermal mixing of Zn ions and 1,4-benzenedicarboxylic acid (Zn/BDC) moieties to adsorb methyl orange (MO), and amoxicillin (AMX). Results obtained show that MO and AMX adsorption capacity by Zn/BDC (mg/g) was found to increase with increase in solution concentration, for each contaminant type. Three isotherm models were applied to the adsorption data: Freundlich, Langmuir, and Temkin. R2 values obtained for the adsorption of MO, 0.9778, 0.8589 and 0.9038 for Freundlich, Langmuir and Temkin plots respectively, indicates that all three models fit the adsorption data appreciably good, with the Freundlich isotherm providing the best fit. Those for AMX, 0.6737, 0.0616, and 0.5300 indicated a poor fit, but the Freundlich isotherm came out as best fitting isotherm for AMX, an indication of a multilayer adsorption process. Maximum possible amount of contaminant adsorbed per gram of Zn/BDC deduced from the Langmuir isotherm for the adsorption of both contaminants were 93.46 mg/g and 18.41 mg/g for MO and AMX respectively. This, among other indicators, showed the preference of Zn/BDC for MO relative to AMX. Adsorption kinetic models: pseudo first order, pseudo second order, and Weber-Morris intraparticle diffusion models, gave R2 values that indicate that intraparticle diffusion dominated the adsorption of MO, while the adsorption of AMX followed pseudo second order kinetics, an indicator of chemisorptive mechanism. Calculated Qe values, were in close agreement with experimental values.&#x0D; Freundlich equation ; Adsorption ; Langmuir ; Chemistry ; Methyl orange ; Langmuir adsorption model ; Metal ; Metal-organic framework ; Inorganic chemistry ; Humic acid ; Nuclear chemistry ; Organic chemistry Multicomponent Synthesis of Heterocycles ; Analytical Methods in Pharmaceuticals ; Synthesis of Tetrazole Derivatives
Authors: Jan Ulric Garcia | Douglas R. Tree | Alyssa Bagoyo | Tatsuhiro Iwama | Kris T. Delaney | Glenn H. Fredrickson
Source: ChemRxiv (preprint, 2023-08-28)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Coarsening dynamics of ternary polymer solutions with mobility and viscosity contrasts Using phase-field simulations, we investigate the bulk coarsening dynamics of ternary polymer solutions undergoing a glass transition for two models of phase separation: diffusion-only and with hydrodynamics. The glass transition is incorporated in both models by imposing mobility and viscosity contrasts between the polymer-rich and polymer-poor phases of the evolving microstructure. For microstructures composed of polymer-poor clusters in a polymer-rich matrix, the mobility and viscosity contrasts significantly hinder coarsening, effectively leading to structural arrest. For microstructures composed of polymer-rich clusters in a polymer-poor matrix, the mobility and viscosity contrasts do not impede domain growth; rather, they change the transient concentration of the polymer-rich phase, altering the shape of the discrete domains. This effect introduces several complexities to the coarsening process, including percolation inversion of the polymer-rich and polymer-poor phases---a phenomenon normally attributed to viscoelastic phase separation. Polymer ; Materials science ; Ternary operation ; Microstructure ; Viscosity ; Viscoelasticity ; Glass transition ; Percolation (cognitive psychology) ; Chemical physics ; Phase (matter) ; Thermodynamics ; Composite material ; Chemistry ; Physics ; Computer science ; Organic chemistry Liquid Crystal Research Advancements ; Material Dynamics and Properties ; Solidification and crystal growth phenomena
Authors: Álvaro de Jesús Ruíz-Baltazar | Simón Yobanny Reyes‐López | Néstor Méndez‐Lozano | R. Pérez
Source: Preprints.org (preprint, 2023-12-20)
Field: Chemistry — Organic Chemistry

Sustainable Zeolite-Silver Nanocomposites via Green Methods for Water Contaminant Mitigation and Modeling Approaches This study explores cutting-edge and sustainable green methodologies and technologies for the synthesis of functional nanomaterials, with a specific focus on the removal of water contami-nants and the application of kinetic adsorption models. Our research adopts a conscientious ap-proach to environmental stewardship by synergistically employing eco-friendly silver nanopar-ticles, synthesized using Justicia Spicigera extract as a biogenic reducing agent, in conjunction with Mexican zeolite to enhance contaminant remediation, particularly targeting Cu²⁺ ions. Structural analysis, utilizing X-ray diffraction (XRD) and high-resolution scanning and transmis-sion electron microscopy (TEM and SEM), yields crucial insights into nanocomposite structure and morphology. Rigorous linear and non-linear kinetic models, encompassing pseudo-first order, pseudo-second order, Freundlich, and Langmuir, are employed to elucidate the kinetics and equilibrium behaviors of adsorption. Results underscore the remarkable efficiency of the Zeolite-Ag composite in Cu²⁺ ion removal, surpassing traditional materials, achieving an im-pressive adsorption rate of 98% for Cu. Furthermore, the Zeolite-Ag composite exhibits maxi-mum adsorption times of 480 minutes. In the computational analysis, an initial mechanism for Cu²⁺ adsorption on zeolites is identified. The process involves rapid adsorption onto the surface of the Zeolite-Ag NP composite, followed by a gradual diffusion of ions into the cavities within the zeolite structure. Upon reaching equilibrium, a substantial reduction in copper ion concen-tration in the solution signifies successful removal. This research represents a noteworthy stride in sustainable contaminant removal, aligning with eco-friendly practices and supporting the potential integration of this technology into environmental applications. Consequently, it pre-sents a promising solution for eco-conscious contaminant remediation, emphasizing the utiliza-tion of green methodologies and sustainable technologies in the development of functional na-nomaterials Zeolite ; Adsorption ; Freundlich equation ; Nanocomposite ; Langmuir ; Materials science ; Chemical engineering ; Nanotechnology ; Nanomaterials ; Chemistry ; Catalysis ; Organic chemistry Nanomaterials for catalytic reactions
Authors: Haydar U. Zaman | Ruhul A. Khan
Source: International Journal of Advanced Science and Engineering (article, 2023-05-22)
Field: Materials Science — Polymers and Plastics

An Overview on Properties and uses of Bhendi Fiber Reinforced Polymer Composites frequently used in the aerospace and automotive industries due to their exceptional properties, such as their light weight, high strength, high durability, chemical resistance, wear resistance, fire resistance, electrical resistance, and corrosion resistance. Additionally, they are utilized in building and infrastructure. Polymer composites can be reinforced with a variety of fiber types, including carbon fiber, glass fiber, and natural fiber. Prior to now, only synthetic fiber reinforced polymer composites were used due to their superior mechanical properties and low cost. Carbon and glass fibers are two types of synthetic fibers. Sustainability is a topic that all academics in the current day are concerned with. When it comes to swapping out nonsustainable products for sustainable ones, every industry is faced with a challenging issue. Due Composite material ; Fiber ; Materials science Natural Fiber Reinforced Composites ; Mechanical Engineering and Vibrations Research
Authors: Soumaya Talbi | Amal El Khanchaoui | Latifa Bouissane | Abderrafia Hafid | Mostafà Khouili | Souad Rabi | Abdellatif Essoumhi
Source:  (article, 2023-11-15)
Field: Materials Science — Materials Chemistry

The High Performance of Multi-Metal Layered Double Hydroxides (LDHs) in the Removal of Organic Dyes In this work, both MgNiAl-LDH and MgNiFe-LDH hydrotalcites were utilized to remove the anionic dye Congo red (CR) from an aqueous solution. Samples characterization was carried out by X-ray diffraction (XRD), infrared spectroscopy (IR) and Thermogravimetric/Differential Scanning Calorimetry (TG/DSC). Various parameters were investigated, including the initial dye concentration, adsorbent mass, contact time, solution pH, and temperature. Using classical pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, adsorption kinetics were investigated. The dynamical data fit well with the pseudo-second order kinetic model. The equilibrium adsorption data were analyzed using three linear adsorption models: Langmuir, Freundlich, and Temkin. The findings showed that the Langmuir isotherm adequately predicts experimental results with an ideal correlation coefficient. The isothermal Langmuir model revealed a maximum adsorption capacity of qmax of 5548 mg/g for the MgNiFe-LDH and of 4043 mg/g for MgNiAl-LDH. This result is very useful when selecting sorbents to improve removal technology in the aquatic environment. Freundlich equation ; Langmuir ; Layered double hydroxides ; Adsorption ; Differential scanning calorimetry ; Thermogravimetric analysis ; Hydrotalcite ; Aqueous solution ; Langmuir adsorption model ; Isothermal process ; Materials science ; Congo red ; Chemistry ; Diffusion ; Analytical Chemistry (journal) ; Chemical engineering ; Thermodynamics ; Chromatography ; Physical chemistry ; Organic chemistry Layered Double Hydroxides Synthesis and Applications ; Adsorption and biosorption for pollutant removal ; Phosphorus and nutrient management
Authors: Yiming Gu | Huixia Feng | Bin Wang | Liang Zhang | Sijie Liang | Nali Chen | Lin Tan
Source: Research Square (preprint, 2023-08-04)
Field: Materials Science — Biomaterials

Two-step modification of sepiolite (SDS/isep) and its performance for remediation of Pb contaminated water Abstract To enhance the remediation capability of lead (Pb) polluted water, our approach involved a two-step modification of the initial sepiolite (sep) through inorganic mixed solutions and sodium dodecanesulfonate (referring as SDS/isep), and then the modified sepiolite (SDS/isep) is used to remove Pb 2+ in Pb-contaminated water. Adsorption experiments showed that the SDS/isep had a significantly higher adsorption capacity for Pb 2+ than natural sepiolite (the adsorption capacities before and after modification were 19.04 and 49.10 mg g − 1 ). A series of characterizations combined with adsorption kinetics and thermodynamics analysis revealed the adsorption mechanism of SDS/isep for Pb 2+ . The analysis results show that the monolayer adsorption of SDS/isep to Pb 2+ is mainly carried out by ion exchange, surface hydroxyl complexation, chemical precipitation, and electrostatic attraction, and this adsorption reaction is a spontaneous exothermic process. The above positive results indicate the superiority of the two-step modification strategy of natural sepiolite proposed in this study. Sepiolite ; Adsorption ; Chemistry ; Ion exchange ; Exothermic reaction ; Chemical modification ; Environmental remediation ; Chemical engineering ; Inorganic chemistry ; Contamination ; Organic chemistry ; Ion ; Polymer chemistry Clay minerals and soil interactions ; Adsorption and biosorption for pollutant removal
Authors: Dan Xu | Yang Yang | Lukas Emmerich | Yong Wang | Kai Zhang
Source: Nature Communications (article, 2023-09-26)
Field: Materials Science — Biomaterials

Divergent Deborah number-dependent transition from homogeneity to heterogeneity Heterogeneous structures are ubiquitous in natural organisms. Native heterogeneous structures inspire many artificial structures that are playing important roles in modern society, while it is challenging to identify the relevant factors in forming these structures due to the complexity of living systems. Here, hybrid hydrogels consisting of flexible polymer networks with embedded stiff cellulose nanocrystals (CNCs) are considered an open system to simulate the generalized formation of heterogeneous core-sheath structures. As the result of the modified air drying process of hybrid hydrogels, the formation of heterogeneous core-sheath structure is found to be correlated to the relative evaporation speed. Specifically, the formation of such heterogeneity in xerogel fibers is found to be correlated with the divergence of Deborah number (De). During the transition of De from large to small values with accompanying morphologies, the turning point is around De = 1. The mechanism can be considered a relative humidity-dependent glass transition behavior. These unique heterogeneous structures play a key role in tuning water permeation and water sorption capacity. Insights into these aspects can prospectively contribute to a better understanding of the native heterogeneous structures for bionics design. SILK ; Glass transition ; Self-healing hydrogels ; Nanotechnology ; Polymer ; Homogeneous ; Materials science ; Relative humidity ; Sorption ; Chemical physics ; Polymer science ; Chemical engineering ; Computer science ; Chemistry ; Composite material ; Statistical physics ; Polymer chemistry ; Physics ; Thermodynamics Advanced Cellulose Research Studies ; Advanced Materials and Mechanics ; Advanced Sensor and Energy Harvesting Materials
Authors: Shereen Abd El Gawad | Maha A. Marzouk | Amal A. A. Ammar
Source: Al-Azhar Journal of Pharmaceutical Sciences/Al-Azhar Journal of Pharmaceutical Sciences (article, 2023-03-01)
Field: Chemistry — Organic Chemistry

PREPARATION AND EVALUATION OF SUSTAINED RELEASE MATRIX FORMULATIONS OF VORICONAZOLE Voriconazole is a triazole antifungal with a half-life of 1.7 hours and 96% oral bioavailability. The oral route is the most popular of drug delivery routes. However, there are a few limitations to the traditional dosage form, for instance, fluctuations in plasma drug level. Sustained drug delivery system overcomes these limitations; it helps to maintain stable plasma drug concentrations by decreasing drug r elease and extending the duration of the effect. The main purpose of this study was to formulate voriconazole sustained release dosage form to enhance efficacy, decrease dose frequency, decrease its side effects, and improve patient compliance. The study explored various formulations for producing the sustained-release (S.R) dosage form, as well as assessed the drug's release kinetics and its stability. Methodology: Fourier-transform Infrared Spectroscopy was used to investigate drug-polymer compatibility. The micromeritics of voriconazole powder and its blends were evaluated. Different sustained release tablets were formulated utilizing a wet granulation process and acrylic polymers (Eudragit) i.e., Eudragit RL100 and RS100 alone and as mixtures with different ratios, in different concentrations. In-vitro drug release of formulae was performed for 24 hours. The formula with desired control of drug release and complied with dissolution specifications for SR dosage forms was further evaluated for its stability by storage for 3 months at 30o C and 40o C and 75% relative humidity. Results: no interaction was observed between voriconazole and polymers using FTIR. The powder blends micromeritics were found to be in accordance with the specification. Tablets showed release from 37.29 to 76 % up to 24 hr using USP type I technique. It was found that as polymer concentration increased, the drug release from tablet decreased. The selected formulation F13 which containing 5% of Eudragit RL100:RS100 at a ratio of (10:1) was found to be stable. Conclusion: The obtained data concluded that the F13 formula gave more prominent S.R effect than using Eudragit RL100 or RS 100 alone. Voriconazole ; Matrix (chemical analysis) ; Chemistry ; Medicine ; Chromatography ; Dermatology ; Antifungal Chemical Synthesis and Reactions ; Antimicrobial agents and applications ; Silicone and Siloxane Chemistry
Authors: Hossein Zargarnezhad | Dennis Wong | CN. Catherine Lam | Edouard Asselin
Source: ChemRxiv (preprint, 2023-10-18)
Field: Materials Science — Materials Chemistry

Uniform and local degradation of epoxy-based pipeline coatings under service conditions: salt transport and accelerated exposure analysis The barrier performance of epoxy-based powder coatings for pipelines was evaluated through salt transport measurements through free-standing coating films and via cyclic testing of coated steel panels. The permeability of salt through the free-standing coating films was measured using reverse osmosis techniques under hydraulic pressures relevant to industrial use. These tests showed that fusion bonded epoxy (FBE) and high-performance powder coating (HPPC) have low salt permeability. Accelerated exposure tests were then conducted on the coated steel panels, subjecting them to humidified environments, ultraviolet (UV) light, and salt/fog conditions, all in accordance with ASTM D5894. Some of the exposure conditions (e.g., intensity of UV light and humidity) were modified to examine the impact of each parameter on the relative performance of these coating systems. The reversibility of the coating properties was characterized by a thermal cycling protocol and adhesion performance analysis. Alternative exposure to dry- and wet-cycles (at 60°C and 50°C, respectively), salt/fog conditions and UV light results in irreversible damage to the coatings as early as two weeks in. However, coated panels exposed to a lower UV intensity (one tenth of the value defined by the standard) showed minimal degradation of FBE, meaning that the most critical parameter was the UV radiation exposure. For one 336-h ageing sequence under UV exposure, the HPPC exhibited superior performance compared to FBE. More importantly, our extended exposure sequences showed that while the FBE coating structure undergoes a slow ablation process, indicating significant surface damage, it still retains its effectiveness as a barrier. However, the osmotic pressures around coated pipes and the pre-existing, unavoidable, porosity throughout the coating thickness can facilitate local through-thickness pinholes, which could potentially serve as areas susceptible to cathodic disbondment. Coating ; Materials science ; Epoxy ; Composite material ; Accelerated aging ; Air permeability specific surface ; Relative humidity ; Degradation (telecommunications) Corrosion Behavior and Inhibition ; Concrete Corrosion and Durability ; High voltage insulation and dielectric phenomena