Ethylene Oxide
Mostrando 1-12 de 200 artigos, teses e dissertações.
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1. Per-Aqueous Liquid Chromatography for the Separation of Polar Compounds Preparation and Characterization of Poly(ethylene oxide co dimethylsiloxane) Based Stationary Phase
Poly(ethylene oxide-co-dimethylsiloxane) was thermally immobilized on silica particles-Si(PEO)-to separate small polar compounds with water-rich mobile phases. Poly(ethylene oxide-co-dimethylsiloxane) content on Si(PEO) stationary phase was optimized using a central composite design. Infrared spectroscopy, scanning electron microscopy, and thermogravimetric
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Incorporation of Fluorescent Dyes in Electrospun Chitosan/Poly(ethylene oxide)
Polymeric films have been increasingly investigated due to the ease of miniaturization and integration in several sensor devices. Films obtained from the electrospinning technique have a controlled diameter and homogeneity, and substances can be incorporated into the polymeric network. Electrospinning fiber of chitosan (Ch) and poly(ethylene oxide) (PEO) was
J. Braz. Chem. Soc.. Publicado em: 2021-05
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3. Antimicrobial High-Density Polyethylene (HDPE)/ZnO Nanocomposites Obtained by in situ Polymerization
Nanostructured zinc oxide (ZnO) prepared by combustion in solution was used to obtain nanocomposites. The ZnO particles were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), and scanning electron microscopy (SEM), showing crystallite size of 32 nm and a superficial area of 32.6 m2 g-1. Nanocomposites with 1, 3, and 5 wt.% of ZnO in the
J. Braz. Chem. Soc.. Publicado em: 2020-08
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4. New Insights into the Partitioning of Phenothiazine Dyes in Aqueous Two-Phase Systems
Aqueous two-phase systems (ATPSs) have proven to be efficient and environmentally safe methods for extracting chemical species. However, the driving forces behind the partition of solutes in these systems are still little understood. A complete thermodynamic partitioning of phenothiazine dyes was investigated in poly(ethylene oxide) (PEO) + salt + water ATPS
J. Braz. Chem. Soc.. Publicado em: 2020-08
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5. DINÂMICA MOLECULAR REATIVA DA ABERTURA DO ANEL EPÓXI EM REAÇÕES COM POLIAMINA Ellen
The molecular dynamics simulations were used to study the epoxy ring-opening in the determination of kinetic parameters, with a temperature range from 1500 to 2500 K in a 20 x 20 x 20 Å unit cell containing 15 molecules of C2H4O (ethylene oxide) and 35 molecules of CH6N2 (methanediamine). The activation energy values for epoxy and diamine was 66 and 92 kJ m
Quím. Nova. Publicado em: 2020-05
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6. Behaviour of diferent types of chitosan membranes implanted in horses
RESUMO: A quitosana tem sido utilizada, com sucesso, como biomaterial para diversas espécies e finalidades. Neste estudo foi avaliada a confecção de membranas de quitosana, produzidas a partir de seis tipos de materiais diferentes e foi estudado seu comportamento quando implantadas no tecido subcutâneo do flanco de doze equinos sadios. Foram avaliadas me
Pesq. Vet. Bras.. Publicado em: 02/12/2019
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7. A Sustainable Methodology to Extract Bismuth from Secondary Sources
Bismuth is a critical metal broadly used in cosmetic, medicine and metallurgy. However, its scarcity in Earth’s crust may impair further applications. An alternative is to recover bismuth from secondary sources. In this work, a methodology to extract bismuth from safety valves of discharged gas cylinders is proposed. Extraction and purification of bismuth
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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8. Micellar propolis nanoformulation of high antioxidant and hepatoprotective activity
ABSTRACT The present study reports a promising antioxidant protection by a recently developed micellar propolis formulation, against oxidative stress in in vitro and in vivo models of toxicity. The formulation, based on poplar propolis encapsulated in poly(ethylene oxide)–β-poly(propylene oxide)–β-poly(ethylene oxide) triblock copolymer (PEO26–PPO40�
Rev. bras. farmacogn.. Publicado em: 26/08/2019
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9. Synthesis and characterization of amphiphilic block copolymers by transesterification for nanoparticle production
Abstract Poly(ε-caprolactone)-block-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, triblock) and Poly(ε-caprolactone)-block-(poly(ethylene oxide)−poly(propylene oxide)−poly(ethylene oxide)-poly (ε-caprolactone) (PCL-PEO-PPO-PEO-PCL, pentablock) copolymers were synthesized by transesterification with reduction of PCL molecular mass, enabling
Polímeros. Publicado em: 04/07/2019
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10. Soil Biodegradation of PLA/CNW Nanocomposites Modified with Ethylene Oxide Derivatives
Due to its ester bonds, poly(lactic acid) (PLA) undergoes biodegradation in humid environments, attracting market attention. The goal of this work was to observe the biodegradation in garden soil of PLA nanocomposites with neat (PLA/CNW) and surfactant modified cellulose nanowhiskers (PLA/CNW/S). Three types of surfactants were tested: poly(ethylene glycol)
Mat. Res.. Publicado em: 01/03/2018
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11. Degradation of Poly(Ethylene Oxide) Films Using Crystal Violet
The present study aimed to investigate the degradation of poly(ethylene oxide) (PEO) in the presence of cationic dye crystal violet irradiated under visible light. The preparation of the samples was done in the form of films obtained by casting. Degradation tests were carried out by 120 hours at room temperature. The degradation kinetics of the dye and polym
Mat. Res.. Publicado em: 01/02/2018
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12. Influence of pH in Obtaining Indium Tin Oxide Nanoparticles by Microwave Assisted Solvothermal Method
A systematic study about synthesis of In1-xSnxO2 (ITO) nanostructured crystals by microwave-assisted solvothermal method is reported. Different solutions using InCl3.4H2O and SnCl4.5H2O precursors in ethylene glycol solvent were prepared in distinct pHs (acid and basic ones). The syntheses were performed at 200 ºC using a heating rate of 50 ºC min-1 and so
Mat. Res.. Publicado em: 22/01/2018