Solid-state studies of the crystalline/amorphous character in linear Poly(ethylenimine hydrochloride) (PEI-HCl) polymers and their copper complexes
Linear poly(ethylenimine hydrochloride) (PEI-HCl) polymers with different molecular weights (22, 87, and 217 kDa) and their copper complexes (Cu−PEI) were studied with particular attention to the crystalline/amorphous character of the polymeric chains in lyophilized and crystallized samples by using 1D and 2D solid-state nuclear magnetic resonance, X-ray photoelectron spectroscopy, and X-ray diffraction techniques. Different 13C{1H} cross-polarization and magic angle spinning experiments using delayed contact time, 1H dipolar filter and 1H spin-lock filter were crucial to determine the different mobility domains in the crystallized and lyophilized samples of PEI-HCl and Cu−PEI. 13C direct polarization experiments allowed the quantification of the crystalline/amorphous segments in each sample. The lyophilization process produced an increase in the amorphous fraction, even when some ordered domains were present, whereas the coordination of copper/sulfate ions produced a significant decrease in the mobility of polymer chains, leading to homogeneous and ordered materials even when Cu was desorbed.
| Main Authors: | , , , , |
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| Format: | article biblioteca |
| Language: | eng |
| Published: |
2015
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| Subjects: | Poly ethylenimine hydrochloride, Cooper complexes, Solid state, Characterization, |
| Online Access: | http://hdl.handle.net/11086/24442 |
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