Water Diffusion and Headgroup Mobility in Polymer-like Reverse Micelles: Evidence of a Sphere-to-Rod-to-Sphere Transition

  title={Water Diffusion and Headgroup Mobility in Polymer-like Reverse Micelles: Evidence of a Sphere-to-Rod-to-Sphere Transition},
  author={Ruggero Angelico and Gerardo Palazzo and Giuseppe Colafemmina and Peter Albert Cirkel and Mauro Giustini and Andrea Ceglie},
  journal={Journal of Physical Chemistry B},
A pulsed gradient spin-echo FT 1H NMR study on the system soybean lecithin/water/perdeuterated cyclohexane is presented. The self-diffusion coefficient of water, Dw, was measured as a function of the water content (W0) and was found to show a bell-shaped trend. The composition at which the maximum in Dw occurs is the same at which the viscosity is the highest. We rationalize the rising part of the plot in terms of a water diffusion inside wormlike reverse micelles which increase their length… 
Viscoelasticity and interface bending properties of lecithin reverse wormlike micelles studied by diffusive wave spectroscopy in hydrophobic environment.
The microrheological properties of concentrated PC-cyclohexane reverse wormlike micellar systems are investigated by diffusive wave spectroscopy in apolar medium, combined with bulk shear rheology and a new method for the quantitative estimation of these fundamental parameters is calculated.
Structure and dynamics of polymer-like reverse micelles
We present pulsed-field-gradient NMR and time-resolved small-angle neutron scattering experimental data to bear out the polymer-like nature of long, flexible micelles in the
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Effects of alkyl chain length of oil and water on the shape, size, and internal structure of glycerol monooleate (GMO) reverse micelle have been investigated using small-angle X-ray scattering (SAXS)
The influence of water on phase transitions of a drug-loaded reverse micellar solution into lamellar liquid crystals
Abstract The effects of timolol maleate (TM) as a model drug on the physicochemical properties of a reverse micellar solution (RMS) consisting of lecithin in isopropyl myristate were investigated in
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The findings map the role of hydration at microscopic level in these systems and could enable tailoring reverse micellar systems for applications relying on the structure and dynamics of thereverse micelles, e.g., in catalysis.
Demonstration of a Novel Charge-Free Reverse Wormlike Micelle System.
A novel charge-free reverse wormlike micelle (RWLM) consisting of a ternary mixture of a nonionic amphiphilic block copolymer, fatty acid alkyl ester oil, and water under ambient conditions is demonstrated, demonstrating the sphere-to-worm like micelle transition as confirmed by small-angle X-ray scattering.
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We use complementary experiments—proton NMR diffusometry and relaxometry, deuterium NMR lineshapes, and rheometry—to construct a comprehensive picture of the microscopic structure of a
Structure and Percolation of Inverted Cylindrical Branched Micelles
There have been strong indications that lecithin with trace amounts of water in isooctane forms branched cylindrical micelles at relatively high water content. At a certain volume fraction these
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We report shape, size, and internal cross-sectional structure of diglycerol monomyristate (C₁₄G₂) reverse micelles in n-hexadecane near the critical point using small-angle X-ray scattering (SAXS).
Branching and alignment in reverse worm-like micelles studied with simultaneous dielectric spectroscopy and RheoSANS.
The combined steady-shear electrical and microstructural measurements are capable, for the first time, of resolving branch breaking at low shear rates prior to alignment-driven anisotropy at higherShear rates.