Figure 1: A representative spectrum in the region 3000–2800 cm−1 of PEO in bidistilled water solution. The vibration bands around 2850 and 2925 cm−1 (indicated by arrows) are due to the symmetric stretching and to the asymmetric stretching of the methylene group, respectively. Their intensity decreased significantly after exposure of 2 h (a) and 4 h (b) to a SMF at 200 mT. The spectra of exposed and unexposed samples are represented by red and blue lines, respectively.