jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tegar Nurwahyu Wijaya | Rukman Hertadi
Source: Indonesian Journal of Chemistry (article, 2019-05-29)
Field: Materials Science — Biomaterials

Estimating Factors Determining Emulsification Capability of Surfactant-Like Peptide with Coarse-Grained Molecular Dynamics Simulation The ability of surfactant-like peptides to emulsify oil has become the main focus of our current study. We predicted the ability of a series of surfactant-like peptides (G6D, A6D, M6D, F6D, L6D, V6D, and I6D) to emulsify decane molecules using coarse-grained molecular dynamics simulations. A 1-μs simulation of each peptide was carried out at 298 K and 1 atm using MARTINI force field. Simulation system was constructed to consist of 100 peptide molecules, 20 decane molecules, water, antifreeze particles and neutralizing ions in a random configuration. Out of seven tested peptides, M6D, F6D, L6D, V6D, and I6D were able to form emulsion while G6D and A6D self-assembled to order b-strands. A higher hydropathy index of amino acids constituting the hydrophobic tail renders the formation of an emulsion by peptides more likely. By calculating contact number between peptides and decanes, we found that emulsion stability and geometry depends on the structure of amino acids constituting the hydrophobic tail. Analysis of simulation trajectory revealed that emulsions are formed by small nucleation following by fusion to form a bigger emulsion. This study reveals the underlying principle at the molecular level of surfactant peptide ability to form an emulsion with hydrophobic molecules. Chemistry ; Pulmonary surfactant ; Emulsion ; Molecular dynamics ; Decane ; Peptide ; Molecule ; Amino acid ; Nucleation ; Chemical engineering ; Crystallography ; Chemical physics ; Computational chemistry ; Organic chemistry ; Biochemistry Supramolecular Self-Assembly in Materials
Authors: Samira Samadieh | Alireza Dehnad | Behrouz Naghili | Minoo Sadri | Ahad Bazmani
Source: SHILAP Revista de lepidopterología (article, 2019-02-01)
Field: Materials Science — Biomaterials

Hemocompatibility assessment and drug release kinetics investigation from materials based on electrospun nanofibers Objective(s): Polymeric nanofiber has a huge potential for a various biomedical applications such as wound healing and orthopedic implant. Since most of the future applications of therapeutic nanofiber are interacting with human blood components, it is important to investigate hemocompatibility. <br />Methods: In this study, nanofibers with antibacterial properties were synthesized<br />by electrospun of polymeric composite of chitosan (CS), poly (ethylene oxide) (PEO) and vancomycin (vanco). The results obtained from scanning electron microscopy (SEM), FTIR spectroscopy, antibacterial and hemolysis tests of nanofiber were evaluated. The kinetic and drug release mechanism of drug loaded electrospun samples were also investigated by UV-Vis spectrophotometry and the appropriate model was proposed for prediction of drug release.<br />Results: The surface morphology of a composite nanofiber indicated that the nanofiber is flat and smooth. The results of antibacterial tests showed that prepared nanofiber has antibacterial properties against of Staphylococcus aureus and Escherichia coli. Hemolysis test indicate that this nanofiber has non hemolytic impact on red blood cells (RBCs). The model of antibiotic release from the nanofiber was examined and it was found that the release mechanism can be described as Fickian diffusion model. According to this model, the kinetic degree of the drug release is around 0.38.<br />Conclusions: Infections and pathophysiological factors cause delayed healing of wound healing. Therefore, using antibacterial nanofibers for elimination of antibacterial infection from wounds, accelerate wound healing. Nanofiber ; Electrospinning ; Hemolysis ; Antibacterial activity ; Materials science ; Chitosan ; Antibacterial agent ; Chemistry ; Nanotechnology ; Antibiotics ; Composite material ; Medicine ; Polymer ; Organic chemistry ; Bacteria ; Biochemistry Electrospun Nanofibers in Biomedical Applications ; Silk-based biomaterials and applications
Authors: Shaofeng Yuan | Yichi Zhang | Yunfei Xie | Yahui Guo | Yuliang Cheng | He Qian | Zhigang Liu | Junjie Shen | Weirong Yao
Source: Journal of the Science of Food and Agriculture (article, 2019-01-13)
Field: Materials Science — Biomaterials

Scalping of aroma compounds from food simulants into polyethylene terephthalate laminated steel The equilibrium absorption amount of each flavor component was dependent on the temperature under the same concentration (500 µL L<sup>-1</sup> ). The Fickian diffusion model was used for fitting the experimental kinetics values satisfactorily (R<sup>2</sup> = 0.9158-0.9885). © 2019 Society of Chemical Industry. Aroma ; Polyethylene terephthalate ; Diffusion ; Sorption ; Materials science ; Absorption (acoustics) ; Hexanal ; Aroma compound ; Absorption of water ; Kinetics ; Phthalate ; Chemistry ; Organic chemistry ; Food science ; Composite material ; Adsorption ; Thermodynamics Nanocomposite Films for Food Packaging ; Material Properties and Processing ; Effects and risks of endocrine disrupting chemicals
Authors: Wenting Bao | Xianlong Zhang | Hong Wu | Rong Chen | Shaoyun Guo
Source: Polymers (article, 2019-05-14)
Field: Materials Science — Biomaterials

Synergistic Effect of Ultrasound and Polyethylene Glycol on the Mechanism of the Controlled Drug Release from Polylactide Matrices In this paper, the synergistic effect of ultrasound and polyethylene glycol (PEG) on the controlled release of a water soluble drug from polylactide (PLA) matrices was studied. When ultrasound was used following the hot melt extrusion (HME) of the PLA/model drug release system, the release of the model drug (Methylene Blue (MB)) from the PLA when immersed in phosphate buffered saline (PBS) was affected by the variation of the parameters of ultrasound. It was found that no more than 2% PLA dissolved during the in-vitro release study, and the release of the MB from the PLA was diffusion controlled and fit well with the Higuchi diffusion model. Polyethylene glycol (PEG), which has high hydrophilicity and rapid dissolution speed, was blended with the PLA during the melt extrusion to enhance the release of the MB. The analysis of the structure and properties of the in-vitro release tablets of PLA/PEG/MB indicated that the ultrasound could improve the dispersion of MB in the PLA/PEG blends and it could also change the structure and properties of the PLA/PEG blends. Due to the dissolution of the PEG in PBS, the release of the MB from the PLA/PEG drug carrier was a combination of diffusion and erosion controlled release. Thus a new mechanism combining of diffusion and erosion models and modified kinetics model was proposed to explain the release behavior. Polyethylene glycol ; PEG ratio ; Dissolution ; Chemical engineering ; Materials science ; Extrusion ; Diffusion ; Drug delivery ; Controlled release ; Kinetics ; Drug carrier ; Chemistry ; Nanotechnology ; Composite material biodegradable polymer synthesis and properties ; Nanoparticle-Based Drug Delivery ; Hydrogels: synthesis, properties, applications
Authors: Aly Okasha | Hosam Sobhy | Sahar K. Mohamed | Essam E. Khalil
Source: Journal of Textiles Coloration and Polymer Science (article, 2019-07-25)
Field: Materials Science — Polymers and Plastics

Kinetics and thermodynamics of aniline blue adsorption onto cross-linked gelatin/chitosan polymer blends Films of cross-linked gelatin/chitosan blends have been successfully synthesized using glutaraldehyde as a cross-linker. The synthesized samples were characterized using infrared Fourier transformation (FT-IR), and X-ray diffraction (XRD). The solubility in aqueous media, the pH-responsive swelling, and point of zero surface charge were explored. The adsorption efficiency of samples for the removal of the anionic dye aniline blue from aqueous media has been studied. The parameters that affect the adsorption efficiency as pH, initial dye concentration, contact time and temperature have been examined. Kinetics studies showed that the adsorption process was well described by the pseudo-second-order model and the equilibrium adsorption results fitted Freundlich model. Fitting the experimental data with the Dubinin-Radushkevich model indicated a predominant physisorption mechanism. The maximum dye removal achieved by 1:1 gelatin/chitosan at pH 5 and 35°C was 99.8%. The activation energy for the adsorption process increases as the chitosan content increases which indicating chemisorption behavior. Thermodynamic studies indicated that the adsorption is spontaneous, endothermic in nature and results in higher entropy. Adsorption ; Physisorption ; Chitosan ; Freundlich equation ; Gelatin ; Chemisorption ; Aqueous solution ; Chemistry ; Endothermic process ; Point of zero charge ; Kinetics ; Enthalpy ; Chemical engineering ; Materials science ; Polymer chemistry ; Organic chemistry ; Thermodynamics Conducting polymers and applications ; Dyeing and Modifying Textile Fibers
Authors: Wei Zhang | Faqin Dong | Mingxue Liu | Huaiqing Song | Xiaoqin Nie | Tingting Huo | Zhao Yulian | Pingping Wang | Yilin Qin | Lin Zhou
Source: Polish Journal of Environmental Studies (article, 2019-09-18)
Field: Chemistry — Inorganic Chemistry

Reduction and Enrichment of Uraniumafter Biosorption on Inactivated&lt;i&gt;Saccharomyces cerevisiae&lt;/i&gt; Microorganisms not only have a strong biosorption capacity but also can achieve tremendous volume reduction effects for radionuclide wastes. Batch experiments were conducted to investigate the biosorption characteristics of uranium on inactivated Saccharomyces cerevisiae and the volume reduction and enrichment of uranium after biosorption were also studied in combination with the ashing method. The results revealed that inactivated S. cerevisiae biomass was able to adsorb uranium. The maximum removal efficiency and biosorption capacity for uranium were 96.8% and 31.8 mg/g, respectively. Biosorption ; Chemistry ; Saccharomyces cerevisiae ; Uranium ; Nuclear chemistry ; Food science ; Environmental chemistry ; Yeast ; Biochemistry ; Adsorption ; Metallurgy ; Materials science Radioactive element chemistry and processing
Authors: Penka Vasileva | Ivanka Dakova | Tanya Yordanova | Irina Karadjova
Source: Open Chemistry (article, 2019-12-19)
Field: Chemistry — Analytical Chemistry

New composite sorbent for speciation analysis of soluble chromium in textiles Abstract Micrometer-sized silica spheres coated with a layer of Cr(VI) imprinted methylimidazolium ionic liquid were synthesized and applied for fast and selective determination of leachable Cr(VI) in fabrics. The silica cores were synthesized via original seeded growth procedure. Formation of ionic liquid layer onto their surface was simultaneously combined with CrO 4 2− imprinting. The sorbent characterization was accomplished by SEM/ EDS, elemental microanalysis, and thermogravimetry. Excellent separation of Cr(VI) from Cr(III) was achieved at pH 3 for 10 minutes in a batch mode. A mixture of ascorbic and nitric acids was found to be the most efficient eluent. The adsorption equilibrium data were best represented by the Langmuir isotherm model. The sorbent was applied for quantification of Cr(VI) in textile extracts in accordance with international standard ISO105-E04. The analytical procedure developed (LOD 0.015 μg/g (measured by ETAAS), RSD 3−8% for concentration levels of Cr(VI) 0.015-0.5 μg/g) completely meets the requirements of the international textile regulations. Sorbent ; Chromium ; Adsorption ; Ionic liquid ; Thermogravimetry ; Chemistry ; Langmuir adsorption model ; Microanalysis ; Composite number ; Silica gel ; Chromatography ; Nitric acid ; Nuclear chemistry ; Materials science ; Analytical Chemistry (journal) ; Inorganic chemistry ; Catalysis ; Organic chemistry ; Composite material Analytical chemistry methods development ; Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors
Authors: Simone Ciarella | Wouter G. Ellenbroek
Source: Preprints.org (preprint, 2019-02-07)
Field: Materials Science — Polymers and Plastics

Swap-Driven Self-Adhesion and Healing of Vitrimers Vitrimers are covalent network materials, comparable in structure to classical thermosets. Unlike normal thermosets, they possess a chemical bond swap mechanism that makes their structure dynamic and suitable for activated welding and even autonomous self-healing. The central question in designing such materials is the trade-off between autonomy and material stability: The swap mechanism facilitates the healing but it also facilitates creep, which makes the perfectly stable self-healing solid a hard goal to reach. Here, we address this question for the case of self-healing vitrimers made from star polymers. Using coarse-grained molecular dynamics simulations, we study the adhesion of two vitrimer samples and find that they bond together on timescales that are much shorter than the stress relaxation time. We show that the swap mechanism allows the star polymers to diffuse through the material through coordinated swap events, but the healing process is much faster and does not depend on this mobility. Swap (finance) ; Self-healing ; Creep ; Materials science ; Polymer ; Chemical physics ; Stress relaxation ; Composite material ; Nanotechnology ; Computer science ; Chemistry Polymer composites and self-healing ; Advanced Polymer Synthesis and Characterization ; Supramolecular Self-Assembly in Materials
Authors: Zhimao Wu | Gang Yang | Erzhen Mu | Qiuchen Wang | Sebastiaan Meijer | Zhiyu Hu
Source: Nano Convergence (review, 2019-02-14)
Field: Materials Science — Materials Chemistry

Nanofire and scale effects of heat Combustion is a chemical reaction that emits heat and light. Nanofire is a kind of flameless combustion that occurs on the micro-nano scale. Pt/Al<sub>2</sub>O<sub>3</sub> film with a thickness of 20 nm can be prepared as a catalyst by micro-nano processing. When the methanol-air mixture gas passes through the surface of the catalyst, a chemical reaction begins and a significant temperature rise occurs in the catalyst region. Compared to macroscopic combustion, Nanofire has many special properties, such as large temperature gradients, uniform temperature distribution, and fast temperature response. The large temperature gradient is the most important property of Nanofire, which can reach 1330 K/mm. Combined with thermoelectric materials, it can realize the efficient conversion of chemical energy to electric energy. Nanoscale thickness offers the possibility of establishing thermal gradient. On the other hand, large thermal gradient has an effect on the transport properties of phonons and electrons in film materials. From these we can get the scale effects of heat. This article will provide an overview of the preparation, properties and applications of Nanofire, and then a comprehensive introduction to the thermal scale and thermal scale effects. Temperature gradient ; Combustion ; Materials science ; Thermal ; Catalysis ; Nanoscopic scale ; Chemical energy ; Thermoelectric effect ; Scale (ratio) ; Nanotechnology ; Chemical engineering ; Chemical physics ; Thermodynamics ; Chemistry ; Organic chemistry ; Physics ; Meteorology Thermal properties of materials ; Thermal Radiation and Cooling Technologies ; Advanced Thermoelectric Materials and Devices
Authors: Abdul Wasif Shaikh | Sarika Deokar | Khudbudin Mulani | Nayaku Chavan | C. R. Rajan | S. Ponrathnam
Source: Advanced Journal of Chemistry-Section A (article, 2019-08-27)
Field: Materials Science — Materials Chemistry

Synthesis of Acrylonitrile Based High Internal Phase Emulsion Monoliths and their Application in Recovery of Heavy Metal Ions Polymeric monoliths based on acrylonitrile-divinyl benzene were synthesized successfully by high internal phase emulsion (HIPE) polymerization. Highly porous polyHIPEs were prepared by variation in oil to water ratio as well as type and concentration of porogens. The porogens evaluated were toluene, chlorobenzene, heptane and chloroform. The effect of oil to water ratio and porogen type and concentrations on morphology and surface area of polyHIPEs were investigated. The polyHIPEs were modified to amidoxime functionality by treating base catalyzed reaction with hydroxylamine hydrochloride in presence of base. The treated and modified polymeric monoliths were characterized by FT-IR, SEM and surface area analysis. The modified porous polyHIPEs were tested for adsorption of Cr(VI) metal ions at various pH. Acrylonitrile ; Emulsion ; Chlorobenzene ; Metal ions in aqueous solution ; Adsorption ; Chemical engineering ; Materials science ; Toluene ; Chemistry ; Nuclear chemistry ; Polymer chemistry ; Metal ; Catalysis ; Polymer ; Organic chemistry ; Copolymer Pickering emulsions and particle stabilization
Authors: Laurynas Dagys | Sergejus Balčiu̅nas | J. Banys | Feliksas Kuliešius | Vladimir I. Chizhik | Vytautas Balevičius
Source: Lithuanian Journal of Physics (article, 2019-10-28)
Field: Chemistry — Spectroscopy

CP MAS kinetics and impedance spectroscopy studies of local disorder in low-dimensional H-bonded proton-conducting materials The 1 H– 13 C cross-polarization magic angle spinning (CP MAS) kinetics was studied in poly(vinyl phosphonic acid) (pVPA), i.e. material with high degrees of freedom of proton motion along H-bonded chains. It has been shown that the CP kinetic data for the adjacent 1 H– 13 C spin pairs can be described in the frame of the isotropic spin-diffusion approach. The rates of spin diffusion and spin-lattice relaxation as well as the parameters accounting for spin coupling and the effective size of spin clusters have been determined. The local order parameter S ≈ 0.63±0.02, determined as the ratio of the measured dipolar 1 H– 13 C coupling constant and the calculated static dipolar coupling constant, is significantly lower than the values deduced for related sites in other polymers and in series of amino acids. This means that the local disorder of the C–H bonds in pVPA is between those for rather rigid C–H bond configurations having S = 0.8–1.0 and highly disordered –CH 3 groups ( S ~ 0.4). This effect can be attributed to the presence of the proton transfer path where proton motion is easy to activate. The activation energy for the proton motion E a = 59±7 kJ/mol was determined from the impedance spectroscopy data analysing the temperature and frequency dependences of the complex dielectric permittivity of pVPA. The rates of proton spin-lattice relaxation and spin diffusion are of the same order and both run in the time scale of milliseconds. Proton spin crisis ; Proton ; Spin diffusion ; Chemistry ; Dielectric spectroscopy ; Relaxation (psychology) ; Dipole ; Magic angle spinning ; Coupling constant ; Activation energy ; Reaction rate constant ; Nuclear magnetic resonance ; Crystallography ; Molecular physics ; Analytical Chemistry (journal) ; Nuclear magnetic resonance spectroscopy ; Diffusion ; Kinetics ; Physical chemistry ; Stereochemistry ; Thermodynamics ; Physics ; Organic chemistry Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; Electron Spin Resonance Studies
Authors: Burak Türkan | Ahmet Serhan Canbolat | Akın Burak Etemoğlu
Source: Tarım Bilimleri Dergisi (article, 2019-12-02)
Field: Materials Science — Polymers and Plastics

Numerical Investigation of Multiphase Transport Model for Hot-Air Drying of Food Kurutma gıda ürününden sıvı miktarının buharlaştırılarak mikrobiyal bozulmayı önlemek için yaygın şekilde kullanılır. Enerji tüketimini azaltmak ve gıda kalitesini artırmak için kurutma sürecinin modellenmesi çok önemlidir. Literatürde kurutma karakteristiklerinin araştırılmasında farklı yaklaşımlar kullanılmıştır. Bu yaklaşımlar arasında gözenekli ortam yaklaşımı karmaşık bir mekanizmaya sahiptir. Gözenekli ortamda kurutma modelinde gazlar (su buharı ve hava) için moleküler difüzyon, sıvı (su) için difüzyon ve konveksiyon mekanizmaları kullanılmaktadır. Bu çalışmada öncelikle gözenekli malzemenin kurutulması üzerinde büzülme etkisi araştırıldı. Kurutma probleminde hava ve gıda ürünü için lineer olmayan kısmi diferansiyel denklemleri zamana bağlı olarak çözüldü. Kurutma işlemindeki büzülme etkisi ALE (Arbitrary Lagrangian Eulerian) metodu kullanılarak araştırıldı. Physics ; Mathematics Textile materials and evaluations ; Fluid Dynamics and Thin Films ; Fluid Dynamics Simulations and Interactions
Authors: Naoki Somekawa | Atsuki Yamauchi | Kazuo Eda | Toshiyuki Osakai
Source: Langmuir (article, 2019-08-12)
Field: Chemistry — Organic Chemistry

Computational Prediction of Adsorption Equilibrium for Nonionic Surfactants at the Oil/Water Interface The non-Bornian solvation model has been applied for predicting the adsorption equilibrium for nonionic surfactants at the oil (O)/water (W) interface. In the non-Bornian model, the small contribution from the long-range electrostatic interaction is ignored, and the solvation or resolvation energy is formulated based on the short-range solute molecule (or ion)-solvent interactions-cavity formation, Coulomb, polarization, charge transfer, etc. These interaction energies are given by zero, first, and second-order functions of the local electric field (<i>E</i><sub><i>i</i></sub>) on the molecular surface, which can be estimated by density functional theory calculation. In the present study, we considered an adsorption process as "partial" transfer of a molecule across the O/W interface. Using a non-Bornian, semi-empirical equation for the Gibbs energy of transfer of nonionic molecules, the adsorption states of alkyl alcohols (1-dodecanol, 1-octanol, and 1-hexanol) at the 1,2-dichloroethane/W interface were successfully predicted. The orientation angle (θ), the rotation angle (ω), and the penetration depth into the O phase (<i>d</i>) of the alcohols in the adsorption state could be estimated. Furthermore, the energies for the adsorption from O and W (Δ<i>G</i><sub>ad</sub><sup>°,O→I</sup> and Δ<i>G</i><sub>ad</sub><sup>°,W→I</sup>) could be estimated theoretically. The values of Δ<i>G</i><sub>ad</sub><sup>°,O→I</sup> for the alcohols studied were in good agreement with those determined experimentally by the drop-weight method. Adsorption ; Interface (matter) ; Chemistry ; Chemical engineering ; Thermodynamics ; Chromatography ; Organic chemistry ; Materials science ; Gibbs isotherm ; Engineering Surfactants and Colloidal Systems ; Petroleum Processing and Analysis ; Spectroscopy and Quantum Chemical Studies
Authors: Mohammad Asif | Abida Abida | Md Tauquir Alam
Source: Zenodo (CERN European Organization for Nuclear Research) (article, 2019-07-01)
Field: Chemistry — Organic Chemistry

Diverse chemical and biological potentials of various pyridazine and pyridazinone derivatives A series of heterocyclic compounds incorporating pyridazine moiety were for diverse biological activities. Pyridazines and pyridazinones derivatives showed wide spectrum of biological activities such as vasodialator, cardiotonic, anticonvulsant, antihypertensive, antimicrobial, anti-inflammatory, analgesic, anti-feedant, herbicidal, and various other biological, agrochemical and industrial chemical activities. The results illustrated that the synthesized pyridazine/pyridazine compounds have diverse and significant biological activities. Mechanistic insights into the biological properties of pyridazinone derivatives and various synthetic techniques used for their synthesis are also described. Pyridazine ; Chemistry ; Computational chemistry ; Environmental chemistry ; Organic chemistry Synthesis and Characterization of Heterocyclic Compounds ; Synthesis and biological activity ; Synthesis and Reactions of Organic Compounds