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

A. Viallat; M.M. Margulies

doi:doi:10.1007/PL00013662

EPJ

a
b
d
e
ap
st
h
plus

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
Annie.viallat@ujf-grenoble.fr

Received 8 July 1999

Abstract
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.