Fluorine-19 NMR relaxation and water penetration in surfactant micelles

Ulmius, Jan; Lindman, Bjoern

doi:10.1021/j150626a035

Cited by 43 publications

(28 citation statements)

References 3 publications

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“…However, these solutes can generally be considered to be non-hydrogen-bond-donating (NHB) solutes. Therefore, the solutes were categorized as non-hydrogen bond donors (1-12), hydrogen bond acceptors (13-24), and hydrogen bond donors (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36).…”

Section: Resultsmentioning

confidence: 99%

Characterization of Chemical Selectivity in Micellar Electrokinetic Chromatography. 4. Effect of Surfactant Headgroup

Trone

Khaledi

1999

Anal. Chem.

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The influence of surfactant headgroups on migration behavior in micellar electrokinetic chromatography is examined. Using linear solvation energy relationships (LSER) and functional group selectivity studies, the effect of six anionic headgroups on chemical selectivity is characterized. The sodium dodecyl surfactants of the sulfate [SO4-], sulfonate [SO3-], carboxylate [CO2-], carbonyl valine [OC(O)NHCH(CH(CH3)2)CO2-], and sulfoacetate [OC(O)CH2SO3-] anions are investigated. Solute size and the hydrogen-bond-donating ability of the micellar phase play the most significant roles in solute retention in all of the surfactants studied. While solute-micelle hydrogen bonding plays a dominant role in the observed selectivity, the dipolarity and polarizability of the micellar phase also have a small influence. The results also suggest that the hydrogen-bond-accepting ability for surfactants is inversely proportional to the proton acidity (pKa) of its headgroup. The observed hydrogen-bond-donating ability and dipolarity of surfactant systems are believed to be a result of the water that resides near the micelle surface.

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Section: Resultsmentioning

confidence: 99%

Characterization of Chemical Selectivity in Micellar Electrokinetic Chromatography. 4. Effect of Surfactant Headgroup

Trone

Khaledi

1999

Anal. Chem.

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“…In this section characteristic energy expressions are derived for representative systems. M A N U S C R I P T ACCEPTED MANUSCRIPT 18 …”

Section: Thermodynamics Of Self-assembled Systemsmentioning

confidence: 99%

“…For the same purpose of evaluating the degree of water penetration 19 F relaxation rates of partially and perfluorinated sodium carboxylates were recorded [18,150]. The 19 F relaxation arises in part from intermolecular magnetic dipolar interactions and is therefore much more effective for a particular fluorine atom close to 1 H than when close to 2 H (D).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…Considering local motion to be more important than the overall slow mobility, it was interpreted that appreciable water contact exists only close to the micelle surface for octanaoate and higher homologues. However for perfluorinated butyrate considerable water A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 49 contact remains, despite aggregation to oligomers [18,150]. The larger hydrophobicity of fluorinated hydrocarbon surfactants is shown by lower solubility and an order of magnitude lower cmc and the odd contributions of selectively fluorinated surfactants.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

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Phase equilibriums, self-assembly and interactions in two-, three- and four medium-chain length component systems

Rosenholm

2014

Advances in Colloid and Interface Science

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“…19 F NMR relaxation techniques would provide qualitative information about local motions of perfluoroalkyl groups. [21][22][23][24] Advantages of using 19 F NMR include its high sensitivity due to the 100% natural abundance of 19 F. [21][22][23][24] We performed 19 F NMR relaxation time measurements in C 6 D 6 to obtain information about changes in dynamic motions of the perfluoroalkyl group in PStR F 13 upon self-association. The spin-lattice relaxation occurs most effectively through molecular motions whose frequency is comparable to the NMR frequency.…”

Section: Self-association In Benzene (A) Light Scatteringmentioning

confidence: 99%

Synthesis and Characterization of Self-Associative Perfluoroalkyl-End-Capped Polystyrene

Yusa

Yamamoto

Hashidzume

et al. 2002

Polym J

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ABSTRACT:Polystyrene bearing a perfluoroalkyl group at one polymer chain end was synthesized by a "living" radical polymerization of styrene in the presence of 4-perfluoro(n-tetradecanoylamino)-2,2,6,6-tetramethylpiperidinyl-1-oxy. The "living" polymerization was evidenced by the fact that chain extension occurred upon addition of styrene to a prepolymer at an elevated temperature, i.e., the number-average molecular weight increased linearly with monomer conversion while the molecular weight distribution remained narrow independent of the conversion. The presence of the perfluoroalkyl group in the polymer was confirmed from IR and NMR ( 1 H and 13 C) spectra. A preliminary study of the associative behavior of perfluoroalkyl-end-capped polystyrene, using light scattering, spin-lattice relaxation time in 19 F NMR, and fluorescence probe techniques, indicated that self-association of terminal perfluoroalkyl groups occurred in benzene at polymer concentrations higher than ca. 30 g L −1 when weight-average molecular weight is as low as 5500.KEY WORDS 2,2,6,6-Tetramethylpiperidinyl-1-oxy (TEMPO) / Controlled Radical Polymerization / Self-Association / Perfluoroalkyl Group / Diblock copolymers form micelle-like aggregates as a result of the association of a less soluble block when the copolymers are dissolved in a solvent that is good for only one of the blocks. 1-4 For example, amphiphilic diblock copolymers form micelles in aqueous media, hydrophobic blocks constituting a core and the hydrophilic blocks forming a corona. In analogy with amphiphilic diblock copolymers, watersoluble polymers possessing a large hydrophobic substituent at one chain end form micelle-like aggregates in water. This type of end-modified polymers has been synthesized by free-radical polymerization of hydrophilic monomers using hydrophobically modified azo initiators. For example, Winnik et al. [5][6][7] synthesized poly(N-isopropylacrylamide) (PNIPAM) substituted with a dioctadecyl group at its chain end and revealed that the hydrophobe-end-modified PNI-PAM formed multipolymer micelles at temperatures below its lower critical solution temperature in water. In our previous work, we synthesized poly(sodium 2-(acrylamido)-2-methylpropanesulfonate) end-capped with a cholesterol moiety and showed that the polymer underwent multipolymeric micellization in water. 8 A complexity of free radical polymerization initiated by hydrophobically modified azo initiators is that chain termination occurs via recombination or disproportionation, yielding polymers with hydrophobic groups at † To whom correspondence should be addressed.

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Fluorine-19 NMR relaxation and water penetration in surfactant micelles

Cited by 43 publications

References 3 publications

Characterization of Chemical Selectivity in Micellar Electrokinetic Chromatography. 4. Effect of Surfactant Headgroup

Characterization of Chemical Selectivity in Micellar Electrokinetic Chromatography. 4. Effect of Surfactant Headgroup

Phase equilibriums, self-assembly and interactions in two-, three- and four medium-chain length component systems

Synthesis and Characterization of Self-Associative Perfluoroalkyl-End-Capped Polystyrene

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