The chameleon effect in zwitterionic micelles: Binding of anions and cations and use as nanoparticle stabilizing agents

Drinkel, Emma; Souza, Franciane Dutra de; Fiedler, Haidi D.; Nome, Faruk

doi:10.1016/j.cocis.2013.01.001

Cited by 45 publications

(48 citation statements)

References 62 publications

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“…We observed that at pH 4 as well as pH 7, two bands centered at 1560 cm −1 and 1413 cm −1 were evident, probably from the formation of a pyridinium bond, whereas the aldehyde band (1715 cm −1 ) was more pronounced at pH 11 than at neutral pH. Hence, noticing that our immobilization conditions are different from the one described to form pyridinium, possibly, the zwitterionic surfactants might affect on the local pH of the nanoparticles as was previously described [ 43 , 44 ], in which ImS18 would have a larger impact than ImS10 and ImS4. The local pH change would influence on the formation of a pyridinium/hetorocyclic moiety, and as a proof of concept, we performed CAL-B immobilization on NP-ImS4 in the presence of surfactant ImS18 as a contaminant and surprisingly, the band at 1715 cm −1 was not observed ( Figure S18 ), indicating a possible effect of ImS18 on the local pH of the nanoparticle surface.…”

Section: Resultsmentioning

confidence: 53%

Influence of Glutaraldehyde Cross-Linking Modes on the Recyclability of Immobilized Lipase B from Candida antarctica for Transesterification of Soy Bean Oil

et al. 2018

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Lipase B from Candida antarctica (CAL-B) is largely employed as a biocatalyst for hydrolysis, esterification, and transesterification reactions. CAL-B is a good model enzyme to study factors affecting the enzymatic structure, activity and/or stability after an immobilization process. In this study, we analyzed the immobilization of CAL-B enzyme on different magnetic nanoparticles, synthesized by the coprecipitation method inside inverse micelles made of zwitterionic surfactants, with distinct carbon chain length: 4 (ImS4), 10 (ImS10) and 18 (ImS18) carbons. Magnetic nanoparticles ImS4 and ImS10 were shown to cross-link to CAL-B enzyme via a Michael-type addition, whereas particles with ImS18 were bond via pyridine formation after glutaraldehyde cross-coupling. Interestingly, the Michael-type cross-linking generated less stable immobilized CAL-B, revealing the influence of a cross-linking mode on the resulting biocatalyst behavior. Curiously, a direct correlation between nanoparticle agglomerate sizes and CAL-B enzyme reuse stability was observed. Moreover, free CAL-B enzyme was not able to catalyze transesterification due to the high methanol concentration; however, the immobilized CAL-B enzyme reached yields from 79.7 to 90% at the same conditions. In addition, the transesterification of lipids isolated from oleaginous yeasts achieved 89% yield, which confirmed the potential of immobilized CAL-B enzyme in microbial production of biodiesel.

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Section: Resultsmentioning

confidence: 53%

Influence of Glutaraldehyde Cross-Linking Modes on the Recyclability of Immobilized Lipase B from Candida antarctica for Transesterification of Soy Bean Oil

et al. 2018

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“…Examples on the application for hydrogenation and even for the aerobic oxidation of alcohols exist; however, their application towards the oxidation of aliphatic primary alcohols in water is still scarce. [50,45,32,51,52] Eventually, the zwitterionic surface-active ionic liquid [C 12 im-C 4 -SO 3 ] 7 performed better than the dicationic ones reaching a maximum yield of 35%. Similar surface-active ionic liquids were found to stabilize Palladium nanoparticles in water via the formation of a double layer, and applications in hydrogenations were reported.…”

Section: Impact Of Ionic Liquid Structurementioning

confidence: 99%

Surface-active ionic liquids in catalysis: Impact of structure and concentration on the aerobic oxidation of octanol in water

Cognigni

Kampichler

Bica

2017

Journal of Colloid and Interface Science

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We present design and synthesis of surface-active ionic liquids for the application in micellar catalysis. A series of 1-methyl-3-dodecylimidazolium based ionic liquids with variable core structures including dicationic and zwitterionic ones was synthesized and characterized. These surface-active ionic liquids where applied in the aerobic oxidation of aliphatic alcohols to carbonyl compounds. A strong dependence on the ionic liquid concentration and structure was identified, which is in accordance with the concepts of micellar catalysis. Optimum conditions for the oxidation of 1-octanol could be identified, and the use of surface-active ionic liquids strongly improved the reaction performance compared to pure water. Under optimized conditions, it was possible to isolate up to 75% of octanoic acid using only small amounts of surface-active ionic liquid in a 0.05mM solution in water without further ligands.

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“…− , are adsorbed more strongly than more hydrophilic anions, such as Cl − . 51 Because of its location, the negatively charged phosphate has to overcome shielding caused by the positively charged ammonium group before interacting with cations in the salt solution. Secondly, the short distance between the phosphate and the backbone results in a reduced flexibility, which may be required for it to interact with cations.…”

Section: Effect Of Ionic Strengthmentioning

confidence: 99%

Influence of salt on the solution dynamics of a phosphorylcholine-based polyzwitterion

Zhang

Madsen

Warren

et al. 2017

European Polymer Journal

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The diffusion of a polyzwitterion, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), in aqueous solution containing different alkali halides was studied by fluorescence correlation spectroscopy at single molecule level. It was found that the halide anion has a greater effect on the radius of zwitterionic PMPC molecules than alkali cations, which is due to the mechanism by which PMPC molecules interact with the surrounding hydrogen bond network of water molecules and adsorbed ions. With the addition of salt, the size of PMPC remains constant while its diffusion coefficient is reduced slightly, although larger cations (e.g. K +) result in slightly increased diffusion coefficient for 1 M potassium chloride-based solutions. This enhanced diffusion coefficient is attributed to the decrease in the viscosity of the aqueous solution on the addition of salt. When the counter-ion was varied in potassium-based salts, different effects were observed for different anions, resulting a reduction in the diffusion coefficient as a function of salt concentration. This reduction was modest for KBr, but significant for KI. Overall, no discernible changes were observed as the size of the PMPC coil was varied, except in case of KI for which a significant increase was observed at higher ionic strength. Divalent cations (Ca 2+ and Mg 2+), produced similar effects to those found for monovalent cations. These effects are explained by the interaction of PMPC with the hydrogen bond network of water molecules and with the adsorbed ions.

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The chameleon effect in zwitterionic micelles: Binding of anions and cations and use as nanoparticle stabilizing agents

Cited by 45 publications

References 62 publications

Influence of Glutaraldehyde Cross-Linking Modes on the Recyclability of Immobilized Lipase B from Candida antarctica for Transesterification of Soy Bean Oil

Influence of Glutaraldehyde Cross-Linking Modes on the Recyclability of Immobilized Lipase B from Candida antarctica for Transesterification of Soy Bean Oil

Surface-active ionic liquids in catalysis: Impact of structure and concentration on the aerobic oxidation of octanol in water

Influence of salt on the solution dynamics of a phosphorylcholine-based polyzwitterion

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