The conformation and arrangement of poly(ethylene oxide) (PEO) chains in clay galleries is still controversial. In our work, various spectroscopic methods have been used to explore the conformation of PEO in clay galleries. The melt intercalation process is investigated using variable-temperature Raman spectroscopy. It is found that the sharp peak at 860 cm−1 appears with an increase of the intercalation time, suggesting the formation of a crown-ether-like association between the cations and the PEO oxygen atoms. Two-dimensional infrared correlation analysis also suggests the presence of the crown-ether-like association between them. Therefore, a distorted helical conformation may be a more accurate way to describe the conformation of the PEO chains in the clay galleries, and a single-layer arrangement is suggested.
Hu Zhou, Zuliang Lai, and Peiyi Wu, "Conformation of Poly(ethylene oxide) Chains in Clay Galleries," Appl. Spectrosc. 64, 912-917 (2010)