On the Spontaneous Formation of Potassium Hydrofluoride during the Aging of a Partially Dehydrofluorinated PVDF Film.

Autor: Zhivulin, V. E., Pesin, L. A., Evsyukov, S. E., Khairanov, R. Kh., Denyaev, N. S.
Zdroj: Journal of Surface Investigation: X-Ray, Synchrotron & Neutron Techniques; Jun2023, Vol. 17 Issue 3, p701-706, 6p
Abstrakt: Infrared (IR) spectroscopy, X-ray phase analysis, and scanning electron microscopy are used to study the spontaneous formation and increase in the amount of potassium hydrofluoride in the inner region of a sample of a partially chemically dehydrofluorinated polyvinylidene fluoride (PVDF) film during its long-term aging. The most probable mechanism behind the synthesis of potassium hydrofluoride is oxidative degradation of the sample with the formation of fluorocarbonyl groups and their subsequent hydrolysis under the action of atmospheric water. This results in the formation of hydrogen fluoride, which combines with potassium fluoride, a byproduct of primary dehydrofluorination. An increase in the content of potassium hydrofluoride continues as the sample ages until potassium fluoride remains in it. The appearance and subsequent development of spectral features characteristic of out-of-plane librational vibrations of water tetramers indicates the formation of a system of nanoscale pores in the sample after 100 000 min of its aging. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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