Specific Alkali Cation Effects in the Transition from Micelles to Vesicles through Salt Addition

Renoncourt, Audrey; Vlachy, Nina; Bauduin, Pierre; Drechsler, Markus; Touraud, Didier; Verbavatz, Jean‐Marc; Dubois, M.; Kunz, Werner; Ninham, Barry W.

doi:10.1021/la062837z

Cited by 115 publications

(88 citation statements)

References 64 publications

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“…Sammalkorpi and Haataja 45 provided molecular dynamics simulation results showing that Ca 21 yielded stronger salt bridges between charged SDS head groups and Na 1 showed no specific binding to micelles and stayed highly mobile on the micellar surface. 46 Our results (Supporting Information, Figure S1) show that Ca 21 destabilizes pure SDS solutions at 25 mM, whereas up to 0.5M concentration of Na 1 did not. If indeed the cations were able to interact with the SDS micelles in the PEC core, we expected that Na 1 would lead to a more stable solution; this was contrary to our results.…”

Section: Articlementioning

confidence: 63%

Effects of monovalent and multivalent ions on the stability of a polyelectrolyte complex with entrapped surfactants

Gao

Chowdhury

Liang

et al. 2015

J of Applied Polymer Sci

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In this article, we report the effects of nine different monovalent and multivalent salts on the particle size and stability of refined, positively charged polyelectrolyte complexes (PECs) with entrapped surfactant. Dynamic light scattering and f potential measurements of these polymeric particles as a function of various salt concentrations showed that both counter ions and co-ions induced a concentration-dependent increase in the particle size and a decrease in the f potential. We found that the anion concentration where the particle size doubled and the maximum anion concentration beyond which particle precipitation occurred (C a,max ) demonstrated a power law dependence on the anion valence. Moreover, for anions of the same valence but different hydration radio, C a,max decreased in the following order: NO 3 ! Cl ! HPO 4 22 > SO 4 22 > PO 4 32. However, unlike the case of hard colloids where co-ions have relatively little effect on particle interactions, the co-ions also increased the hydrodynamic radii of our PECs in the following order:. Furthermore, we found that the entrapped surfactants were shielded from the adverse effect of multivalent ions; this established that the monovalent and multivalent ions interacted with the polyelectrolyte shells of the PEC. This behavior was in contrast with the effect of salts on mixtures containing the polyelectrolyte and surfactant components, where the addition of salts typically causes an interaction with the individual components. Because several biomedical and technological applications involving PECs require saline environments, our studies provide insight into how small ions influence the PEC stability in applications involving varying salinities.

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Section: Articlementioning

confidence: 63%

Effects of monovalent and multivalent ions on the stability of a polyelectrolyte complex with entrapped surfactants

Gao

Chowdhury

Liang

et al. 2015

J of Applied Polymer Sci

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“…24,28 Then, in our case, while Cs + is in the closest (farthest) contact with the head group of SDS (KL), Li + is highly (loosely) bounded to the head group of KL (SDS). 24,28,30,31 If we compare the strength of the counterion binding of alkali cations to the carboxylate (i.e. KL) micelles, it decreases following the sequence Li + >Na + >K + >Rb + >Cs + and, for SDS micelles, the reversed order is observed.…”

Section: Resultsmentioning

confidence: 99%

Investigation of the interaction of alkali ions with surfactant head groups for the formation of lyotropic biaxial nematic phase via optical birefringence measurements

Akpınar

Reis²,

Neto³

2013

SPIE Proceedings

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Lyotropic liquid crystals exhibiting nematic phases were obtained from the mixtures potassium laurate/alkali sulfate salts (M 2 SO 4 )/1-undecanol (UndeOH)/water and sodium dodecyl sulfate (SDS)/M 2 SO 4 /1-dodecanol (DDeOH)/water, where M 2 SO 4 represents the alkali sulfate salts being Li 2 SO 4 , Na 2 SO 4 , K 2 SO 4 , Rb 2 SO 4 or Cs 2 SO 4 . The birefringences measurements were performed via laser conoscopy. Our results indicated that cosmotropic and chaotropic behaviors of both ions and head groups are very important to obtain lyotropic biaxial nematic phase. To obtain the biaxial nematic phase, surfactant head group and ion present in lyotropic mixture have relatively opposite behavior, e.g. one more cosmotropic (more chaotropic) other less cosmotropic (less chaotropic) or vice versa.

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“…to promote vesicle formation [9][10][11] . Indeed, according to Grillo et al 9) , the free ions produced by the salt dissociation can screen the repulsive electrostatic interactions between the micelles in solution and lead to vesicle formation.…”

Section: F Arsac and H Hidakamentioning

confidence: 99%

DNA Damage Photoinduced by Titanium Dioxide in the Presence of Anionic Vesicles under UV Illumination: Influence of Sodium Chloride Concentration

Arsac

Hidaka

2007

J. Oleo Sci.

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The DNA damage caused by TiO 2 under in vitro conditions by UV-A exposure in the presence of anionic vesicles of Aerosol OT (AOT) was investigated. The supercoiled form (S) in DNA plasmids was converted to the linear form (L) via the relaxed form (R). The DNA damage was slower in the presence of AOT vesicles prepared in aqueous NaCl solution. Moreover, the presence of AOT vesicles in solution after 6 h of UV irradiation was confirmed with an optical microscope. Probably, a fraction of the DNA was protected by random trapping during sonication. However, the addition of NaCl needed for the vesicle formation can decrease the TiO 2 activity. On the other hand, in the absence of vesicles the NaCl concentration led to a profound influence on the adsorption of DNA onto the TiO 2 surface. During UV irradiation, the degradation rate of DNA increased with increasing the salt concentration.Solutions containing vesicles were prepared at various NaCl concentrations between 10 mM and 75 mM. Consequently, the salt concentration had no significant effect on the DNA damage. The presence of NaCl can play a deleterious role during the photoinduced process. However, the encapsulation of a fraction of DNA is not excluded. In such conditions, the DNA could be protected against the reactive oxygen species.

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Specific Alkali Cation Effects in the Transition from Micelles to Vesicles through Salt Addition

Cited by 115 publications

References 64 publications

Effects of monovalent and multivalent ions on the stability of a polyelectrolyte complex with entrapped surfactants

Effects of monovalent and multivalent ions on the stability of a polyelectrolyte complex with entrapped surfactants

Investigation of the interaction of alkali ions with surfactant head groups for the formation of lyotropic biaxial nematic phase via optical birefringence measurements

DNA Damage Photoinduced by Titanium Dioxide in the Presence of Anionic Vesicles under UV Illumination: Influence of Sodium Chloride Concentration

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