Homogeneous length scale of shear-induced multilamellar vesicles studied by diffusion NMR.

Ingrid Åslund, Bruno Medronho, Daniel Topgaard, Olle Söderman, Claudia Schmidt

Research output: Contribution to journalArticlepeer-review

13 Citations (SciVal)

Abstract

A recently developed protocol for pulsed gradient spin echo (PGSE) NMR is applied for the size determination of multilamellar vesicles (MLVs). By monitoring the self-diffusion behavior of water, the technique yields an estimate of the homogeneous length scale λ(hom), i.e. the maximum length scale at which there is local structural heterogeneity in a globally homogeneous material. A cross-over between local non-Gaussian to global Gaussian diffusion is observed by varying the experimentally defined length- and time-scales. Occasional observation of a weak Bragg peak in the PGSE signal attenuation curves permits the direct estimation of the MLV radius in favorable cases, thus yielding the constant of proportionality between λ(hom) and radius. The microstructural origin of the Bragg peak is verified through Brownian dynamics simulations and a theoretical analysis based on the center-of-mass diffusion propagator. λ(hom) is decreasing with increasing shear rate in agreement with theoretical expectations and results from (2)H NMR lineshape analysis.
Original languageEnglish
Pages (from-to)291-299
JournalJournal of Magnetic Resonance
Volume209
DOIs
Publication statusPublished - 2011

Subject classification (UKÄ)

  • Physical Chemistry

Fingerprint

Dive into the research topics of 'Homogeneous length scale of shear-induced multilamellar vesicles studied by diffusion NMR.'. Together they form a unique fingerprint.

Cite this