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Characterizing the Structure and Phase Transformation of Poly(ethylene Oxide)-Urea Complexes Using Terahertz Time-Domain Spectroscopy. | LitMetric

Characterizing the Structure and Phase Transformation of Poly(ethylene Oxide)-Urea Complexes Using Terahertz Time-Domain Spectroscopy.

Appl Spectrosc

Department of Materials Science and Engineering, College of Science, China University of Petroleum, Beijing, China.

Published: November 2017

AI Article Synopsis

  • Terahertz time-domain spectroscopy (THz-TDS) is used to analyze the structure and phase transition (α to β) in poly(ethylene oxide) (PEO)-urea complexes, highlighting the role of hydrogen bonding.
  • The α-form PEO-urea complex exhibits two THz absorption bands at 1.12 and 1.24 THz, linked to hydrogen bonding interactions, while the β-form shows a single band at 1.48 THz-specific to urea interactions.
  • A polarized THz-TDS study indicates that the orientation of urea-urea hydrogen bonds changes by 90° during the transition from the β to α phase, showcasing TH

Article Abstract

Terahertz time-domain spectroscopy (THz-TDS) was employed to characterize the structure and α→β phase transformation of poly(ethylene oxide) (PEO)-urea complexes. While the THz responses of α- and β-form complexes are both originated from hydrogen bonding interactions, they possess different THz absorption bands. The α-form PEO-urea complex shows two bands at 1.12 and 1.24 THz, which are vibration modes due to the hydrogen bonding among urea and between PEO and urea, respectively; the β-form PEO-urea complex shows a band at 1.48 THz, which is a vibration mode due to the hydrogen bonding among urea. A polarized THz-TDS study demonstrates that the urea-urea hydrogen bonding direction rotates 90° during the β→α transformation process. This study reveals the great potential of THz-TDS for investigating polymer-small molecule complexes.

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Source
http://dx.doi.org/10.1177/0003702817722573DOI Listing

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