Fourier transform nmr self-diffusion and microemulsion structure

doi:10.1016/0021-9797(81)90351-9

Journal of Colloid and Interface Science

Volume 83, Issue 2, October 1981, Pages 569-582

https://doi.org/10.1016/0021-9797(81)90351-9 Get rights and content

Abstract

A novel Fourier transform pulsed-gradient spin-echo ¹H and ¹³C NMR method was employed to obtain multicomponent self-diffusion data for seven microemulsion systems. These included ionic surfactant-cosurfactant (short- or long-chain alcohol)-hydrocarbon-water, nonionic surfactant-hydrocarbon-water, and ionic surfactant (of the swelling type)-hydrocarbon-water systems. For the short-chain alcohol (butanol or pentanol) systems both water, hydrocarbon, and alcohol self-diffusion are very rapid over wide concentration regions. In contrast to micellar solutions and certain liquid crystalline phases there is apparently no marked separation into hydrophobic and hydrophilic domains; this is considered to be due to the alcohol having a compatibility with both aqueous and hydrocarbon environments as well as internal interfaces. There appear to be no extended well-defined structures in these systems. Instead the microemulsions are argued to have very flexible and low-order internal interfaces which open up and reform at a short time scale. It seems reasonable to assume a polydispersity in aggregate size and shape and it appears to be a clear possibility that there are mainly quite small aggregates. The nonionic surfactant system shows strong resemblances to the short-chain alcohol system while the remaining systems (long-chain alcohol or absence of alcohol) show a more pronounced separation into hydrophobic and hydrophilic regions.

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²: Permanent address: Institute of Physical Chemistry, Uppsala University, Box 532, S-751 21 Uppsala, Sweden.

³: Present address: Isotope Department, Weizmann Institute of Science, Rehovot, Israel.

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Fourier transform nmr self-diffusion and microemulsion structure

Abstract

Phys. Rep.

J. Magn. Reson.

J. Magn. Reson.

Polymer

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

Adv. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

Biophys. Chem.

J. Colloid Interface Sci.

J. Magn. Reson.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Phys. Chem.

Chem. Scripta

Chem. Scripta

J. Chem. Phys.

Phys. Rev.

Rev. Sci. Instrum.