Micelles
Mostrando 13-24 de 317 artigos, teses e dissertações.
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13. MOLECULAR THERMODYNAMICS OF MICELLIZATION: MICELLE SIZE DISTRIBUTIONS AND GEOMETRY TRANSITIONS
Abstract Surfactants are amphiphilic molecules that can spontaneously self-assemble in solution, forming structures known as micelles. Variations in temperature, pH, and electrolyte concentration imply changes in the interactions between surfactants and micelle stability conditions, including micelle size distribution and micelle shape. Here, molecular therm
Braz. J. Chem. Eng.. Publicado em: 2016-09
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14. SÍNTESE E CARACTERIZAÇÃO DE SURFACTANTES ALQUILFENIL POLIGLICOSÍDICOS A PARTIR DA AMILOSE E ALQUIL FENÓIS EXTRAÍDOS DO LCC NATURAL
The surfactants were synthesized by condensing the obtained oligosaccharides of amylose and alkyl phenols extracted from the natural cashew nut shell liquid (nCNSL). The Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR) data showed aromatic ring bands, glycosidic rings, olefins and paraffins. The Nuclear Overhauser Effect Sp
Quím. Nova. Publicado em: 2016-08
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15. Modeling Chemical Reactivity in Ionic Detergent Micelles: a Review of Fundamentals
Ionic detergent micelles have the capacity to solubilize organic substrates, interact selectively with counterions, repel coions, exhibit partial "dissociation" of the counterions, grow in size with added salt, affect the position of chemical equilibria, accelerate or inhibit the rates of chemical reactions, modulate photochemical reactivity and determine th
J. Braz. Chem. Soc.. Publicado em: 2016-02
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16. Multifunctional Imidazole-Derived Polymeric Catalyst for Dephosphorylation Reactions Potentiated by Cationic and Anionic Micelles
Results confirm the catalytic potential of imidazole groups anchored on the polymeric backbone of polyvinylimidazole (PVI) in dephosphorylation reactions with di- and tri-phosphoesters, promoting impressive enhancements up to 107-fold. We propose the imidazole groups on PVI react by nucleophilic catalysis (neutral specie) with a phosphate triester and bifunc
J. Braz. Chem. Soc.. Publicado em: 2016-02
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17. ORGANIC MATTER AND HUMIC FRACTIONS OF A HAPLIC ACRISOL AS AFFECTED BY COMPOSTED PIG SLURRY
The goal of this study was to investigate the effect of composted pig slurry (PS) on the organic matter concentration and distribution of humic acid (HA), fulvic acid (FA) and humin (HU) fractions. The fractions were quantified following the addition of composted PS to the soil, which was produced with no acidification (T2) or with acidification with H3PO4 (
Quím. Nova. Publicado em: 2016-01
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18. Chlorophyllin Derivatives as Photosensitizers: Synthesis and Photodynamic Properties
Two new photosensitizers (PSs) derived from copper-chlorophyllin were designed to have excitation wavelengths appropriate for the use in photodynamic therapy (PDT) and to have amphiphilic character with positive charge, which favors binding to cell membranes and walls and the intracellular localization in mitochondria. Herein we describe the synthesis and ch
J. Braz. Chem. Soc.. Publicado em: 2015-12
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19. SPECTROSCOPIC STUDY OF ALUMINUM PHTHALOCYANINE CHLORIDE (AlPcCl) IN HOMOGENEOUS AND MICRO-HETEROGENEOUS MEDIA CONSISTING OF P-123 AND F-127 POLYMERIC MICELLES
Aluminum phthalocyanine chloride (AlPcCl) is a photoactive compound which has been used as a photosensitizer (PS) in photodynamic therapy (PDT). Its spectroscopic properties have been studied in solvents of different polarities (ethanol, acetone, dimethylsulfoxide and chloroform). Its solubility has been found to decrease with increasing solvent polarity,
Quím. Nova. Publicado em: 2015-06
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20. Urea decreases specific ion effects on the LCST of PMMA-block-PDMAEMA aggregates
Urea is a well-known additive used as a mild protein denaturant. The effect of urea on proteins, micellar systems and other colloids is still under debate. In particular, urea has shown interesting effects on the ion binding in systems like charged micelles, vesicles or Langmuir-Blodgett films. The urea effect on polymeric aggregates in water is still an ope
Polímeros. Publicado em: 2014-12
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21. Aqueous Micelles as Catalytic Nanoreactors for Dephosphorylation Reactions
A reação entre um novo derivado de imidazol, 3,5-bis((1H-imidazol-1-il)metil)anilina (BIm), e o triéster de fosfato dietil 2,4-dinitrofenil fosfato (DEDNPP), que procede por um mecanismo SN2(P), é substancialmente acelerada em presença do surfactante catiônico brometo de cetiltrimetrilamônio (CTAB) e do surfactante aniônico dodecil sulfato de sódio
J. Braz. Chem. Soc.. Publicado em: 2014-12
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22. Catálise básica usando sílica mesoporosa estabilizada por acrilatos encapsulados
The synthesis of new type of silicas, with structures akin to that of MCM-41, containing polyacrylate-encapsulated micelles in their mesopores is reported. Initially, the monomers were inserted in the aqueous micelles of cetyltrimethylammonium cations. MCM-41 was then prepared in this microemulsion. Finally, the polymerization of the acrylates was initiated
Quím. Nova. Publicado em: 2014-06
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23. Physico-chemical properties of meso-tetrakis(p-methoxyphenyl)porphyrin (TMPP) incorporated into pluronicTM p-123 and f-127 polymeric micelles
The physicochemical properties (solubilization, structural organization and stability) of meso-tetrakis(p-methoxyphenyl)porphyrin (TMPP), a promising photosensitizer for photodynamic therapy, solubilized in polymeric micelles of tri-block copolymers PluronicTM P-123 and F-127, were studied. The formulations obtained by the solid dispersion method led to mono
Quím. Nova. Publicado em: 2014
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24. Time-resolved fluorescence quenching studies of sodium lauryl ether sulfate micelles
Números de agregação (N Ag) de micelas do detergente aniônico lauril éter sulfato de sódio (SLES), com duas subunidades de óxido de etileno, foram determinados a 30 e 40º C por supressão de fluorescência resolvida no tempo, utilizando pireno como sonda fluorescente e o íon N-hexadecilpiridíneo como o supressor. O crescimento das micelas de SLES i
J. Braz. Chem. Soc.. Publicado em: 2013-02