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The impact of external conditions on the structure of perfluorinated ion‐exchange membranes, determined by means of Mössbauer spectroscopy
Author(s) -
Chibirova F. Kh.,
Timashov S. F.
Publication year - 1989
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19890270122
Subject(s) - membrane , mössbauer spectroscopy , chemistry , ion , superparamagnetism , hydrolysis , electrolysis , ion exchange , precipitation , hydroxide , chlorine , ion exchange membranes , analytical chemistry (journal) , inorganic chemistry , chemical engineering , materials science , chromatography , crystallography , organic chemistry , electrolyte , magnetization , magnetic field , electrode , biochemistry , physics , quantum mechanics , meteorology , engineering
To ascertain the changes taking place in their submicrostructure after accelerated tests under the conditions of chlorine electrolysis, perfluorinated ion‐exchange sulfocationic membranes hydrolyzed by different techniques were investigated by means of Mössbauer spectroscopy on a Fe57 nucleus introduced into a membrane as a Fe 3+ counter‐ion and precipitated into its submicropores in the form of superparamagnetic hydroxide particles. Information on the submicroporosity of the investigated polymeric membranes was thus obtained. Different techniques of membrane hydrolysis and the processes of both the passage of current (I ∼ 0.3 A/cm 2 ) through them and of precipitation have been established to change radically the characteristic size of submicropores in the membrane, as well as their size distribution. Thermal treatment in air at T ≈ 423 K is shown to be accompanied by the Fe 3+ ← Fe 2+ ion reduction in the membrane.