2021 Impact factor 1.624
Soft Matter and Biological Physics

Eur. Phys. J. E 2, 117-123

Porous structure of membranes of an acrylonitrile copolymer. Porosity, 1H-NMR permeability

A. Viallat - M.M. Margulies

Laboratoire de Spectrométrie Physique, Université J. Fourier, CNRS, BP 87, 38402 Saint Martin d'Héres cedex, France

Received 8 July 1999

Nanoporous polymer membranes (porosity $\phi\approx
0.7$) used for dialysis are studied from NMR relaxation times of water confined in the pore space. Fast interpore water diffusion is observed. Two structural parameters are evidenced: i) a reduced NMR relaxation time, $\tau$, which reflects the width of the pore-size distribution; ii) the average polymer-grain size of the solid matrix deduced from NMR experiments performed on membranes partially filled by water. A relation is found between the ratio $k/\tau^2$, where k is the permeability to water and the porosity. This relation is in qualitative agreement with numerical simulations reported in the literature on low-porosity systems and with experimental results obtained for sedimentary rocks and for fused glass model systems. It supports the idea that $\tau$ is the relevant structural parameter to describe convective transport in a wide class of porous systems.

81.05.Rm Porous materials; granular materials - 76.60.Es Relaxation effects - 47.55.Mh Flows through porous media

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