Ethylene Oxide
Mostrando 13-24 de 200 artigos, teses e dissertações.
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13. Effect of Acetonitrile and N,N-Dimethylformamide on the Formation of Poly(ethylene oxide)-Sodium Alkyl Sulfate Aggregates
The effects of low contents of acetonitrile (AN) or N,N-dimethylformamide (DMF) on the aggregation of sodium alkyl sulfate surfactants, in the absence and presence of poly(ethylene oxide) (PEO), were investigated using conductivity and isothermal titration calorimetry. The cosolvents slightly changed the critical micellar concentrations and did not alter the
J. Braz. Chem. Soc.. Publicado em: 2018-01
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14. Solvothermal Reduction of Graphite Oxide Using Alcohols
In the present work, we use either ethanol or ethylene glycol as reducing agents through the solvothermal method for graphite oxide reduction. A sulfuric acid treatment before the reduction process was also applied to evaluate its influence on the epoxy group ring-opening reaction. Reduced graphene oxide (RGO) samples were obtained with morphology like crump
Mat. Res.. Publicado em: 18/12/2017
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15. Thermoplastic Elastomers Containing Zinc Oxide as Antimicrobial Additive Under Thermal Accelerated Ageing
Styrene-ethylene/butylene-styrene (SEBS) copolymer- based thermoplastic elastomers (TPE) are applied in the production of household items used in places with conditions for microbial development. Metal oxides like zinc oxide (ZnO) and others can be added to the TPE composition to prevent microbial growth. The aim of this study is to evaluate the effect of th
Mat. Res.. Publicado em: 17/08/2017
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16. Synergistic Effect in Drug Solubility by New Binary Micelles of Poly(ε-caprolactone)-poly(ethylene oxide) and F127®
Binary mixtures of block copolymers E114CL20 and E97P69E97 (F127(®)) were prepared in order to tailor a drug delivery system with synergistic effect, concerning dilution stability and high drug solubility. Both reduction of the critical micelle concentrations (CMC) values and enhance hydrophobic drug solubility in F127/E114CL20 mixtures (30-50 wt.%) were ob
J. Braz. Chem. Soc.. Publicado em: 2017-07
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17. Evolution of TiO2 Nanotubular Morphology Obtained in Ethylene Glycol/Glycerol Mixture and its Photoelectrochemical Performance
The evolution of TiO2 nanotubular morphology, synthesized in a mixture of fluorinated ethylene glycol and glycerol electrolyte, was studied as a function of the anodization time. The samples were characterized by FEG-SEM, XRD, XPS, UV-Vis and EIS. The formation of single-or double-walled TiO2 nanotube structure can be efficiently controlled by the anodizatio
Mat. Res.. Publicado em: 18/05/2017
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18. Hydrocortisone release from tablets based on bioresorbable poly(ether-ester-urethane)s
Abstract Bioresorbable linear poly(ether-ester-urethane)s with different hydrophilic characteristics were synthesized from triblock copolymers of poly(ε-caprolactone)-poly(ethylene oxide)-poly(ε-caprolactone) (PCL-PEO) as macrodiols, and L-lysine diisocyanate (LDI) or hexamethylenediisocyanate (HDI) were used as the required diisocyanates. Macrodiols were
Braz. J. Pharm. Sci.. Publicado em: 20/04/2017
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19. Preparation of Polymeric Micelles of Poly(Ethylene Oxide-b-Lactic Acid) and their Encapsulation With Lavender Oil
Nanoparticles comprised of the poly(ethylene oxide)-b-poly (lactic acid) diblock copolymer (PEO-b-PLA) with and without the incorporation of lavender oil were prepared by nanoprecipitation. Diblock copolymers based on a fixed PEO block (5KDa) and two different PLA segments (4.5 or 10KDa) were used. The morphology, encapsulation efficiency, essential oil-poly
Mat. Res.. Publicado em: 03/10/2016
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20. Chemical and Thermal Evaluation of Commercial and Medical Grade PEEK Sterilization by Ethylene Oxide
Many polymers have been used as biomaterials due to their physicochemical characteristics and structural versatility. However, usage on the human body requires sterilization in order to prevent microbial contamination and diminish the risk of rejection or inflammation. This study presents the use of thermogravimetric analysis (TGA) as an alternative to monit
Mat. Res.. Publicado em: 03/06/2016
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21. Pechini Synthesis of Nanostructured Li1.05M0.02Mn1.98O4 (M = Al3+ or Ga3+)
Doped Li1.05M0.02Mn1.98O4 (M = Ga3+ or Al3+) were prepared by Pechini synthesis using lithium and manganese acetates, citric acid, ethylene glycol, and the respective oxide or acetate of the doping ions in molar ratios of 2.00 (Mn1.98 + M0.02) to 1.05 Li. The TGA/DTA of the precursor gels showed weight loss/energy relative to crystallization below 450 ºC. F
Mat. Res.. Publicado em: 17/11/2015
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22. Binary Micellar Solutions of Poly(Ethylene Oxide)-Poly(Styrene Oxide) Copolymers with Pluronic® P123: Drug Solubilisation and Cytotoxicity Studies
The non-commercial copolymers E45S8, E45S17 and their mixtures with Pluronic® P123 (E21P67E21) were studied as carriers of the model drug griseofulvin. Critical micelle concentration (cmc) (dye solubilisation method), drug solubilisation capacity (Scp and Sh) determined by ultraviolet-visible (UV-Vis) spectroscopy and 1H nuclear magnetic resonance (1H NMR)
J. Braz. Chem. Soc.. Publicado em: 2015-11
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23. Evaluation of chemical and mechanical resistance of virgin and recycled poly (ethylene terephthalate) and poly(methylene oxide) when applied as gravel pack in petroleum wells
AbstractNowadays more and more unexpected uses for common materials have been observed, especially when recycled polymers are concerned. In this work, the viability for application of virgin and recycled poly(ethylene terephthalate) (PETvir and PETrec, respectively) and also poly(methylene oxide) (PMO) as granular materials (gravel) for gravel packing in san
Polímeros. Publicado em: 2015-08
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24. A INFLUÊNCIA DA LIGAÇÃO DE HIDROGÊNIO EM REAÇÕES QUÍMICAS: REAÇÃO DE PRILESCHAJEW
Theoretical analysis at the BHandHLYP/6-311++G(d,p) level of theory with the support of QTAIM calculations was used to reinvestigate the structure of an intermolecular system formed between ethylene oxide (C2H4O) and formic acid (HCO2H) after the epoxidation known as the Prileschajew reaction. Geometric and infrared vibration results revealed that HO2CH form
Quím. Nova. Publicado em: 2015-01