Effects of salt and nanoparticles on the segmental motion of poly(ethylene oxide) in its crystalline and amorphous phases: 2H and 7Li NMR studies

The Journal of Physical Chemistry. B
M VogelB Koch

Abstract

We use (2)H NMR to investigate the segmental motion of poly(ethylene oxide) (PEO) in neat and nanocomposite materials that do and do not contain salt. Specifically, in addition to a neat low-molecular-weight PEO, we study mixtures of this polymer with TiO 2 nanoparticles and LiClO 4. To characterize the polymer dynamics over a wide range of time scales, we combine (2)H NMR spin-lattice relaxation, line-shape, and stimulated-echo analyses. The results consistently show that the presence of nanoparticles hardly affects the behavior of the polymer, while addition of salt leads to substantial changes; e.g., it reduces the crystallinity. For neat PEO and a PEO-TiO 2 mixture, stimulated-echo spectroscopy enables measurement of rotational correlation functions for the crystalline phase. Analysis of the decays allows us to determine correlation times, to demonstrate the existence of a nonexponential relaxation, which implies a high complexity of the polymer dynamics in the crystal, and to show that the reorientation can be described as a large-angle jump. For a PEO-TiO 2-LiClO 4 mixture, we use (2)H and (7)Li NMR to study the polymer and the lithium dynamics, respectively. Analysis of the (7)Li spin-lattice relaxation reveals a high li...Continue Reading

References

Feb 21, 1998·Journal of Magnetic Resonance·B GeilH Sillescu
Oct 24, 2000·Journal of Magnetic Resonance·R Bohmer
Aug 3, 2001·Nature·Z GadjourovaP G Bruce
Jan 7, 2005·Nature·Alasdair M ChristiePeter G Bruce
Nov 1, 2005·Solid State Nuclear Magnetic Resonance·D-K Yang, D B Zax
Jun 26, 2007·Solid State Nuclear Magnetic Resonance·Jason R WickhamCharles V Rice

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Citations

Aug 5, 2009·Physical Chemistry Chemical Physics : PCCP·Christiane HackelDetlef Reichert
Apr 3, 2012·The Journal of Chemical Physics·C R HerbersM Vogel
Jun 10, 2021·Advanced Science·Zhiqi ChenCaiyun Wang
Feb 22, 2012·Progress in Nuclear Magnetic Resonance Spectroscopy·Gang Wu, Jianfeng Zhu

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