2024-03-19T13:06:41Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1018362021-06-11T11:18:08Zcom_10261_115com_10261_3col_10261_368
Two-dimensional subnanometer confinement of ethylene glycol and Poly(ethylene oxide) by neutron spectroscopy: Molecular size effects
Barroso-Bujans, Fabienne
Fernández-Alonso, Félix
Cerveny, Silvina
Arrese-Igor, Silvia
Alegría, Ángel
Colmenero de León, Juan
Ministerio de Educación (España)
Eusko Jaurlaritza
Consejo Superior de Investigaciones Científicas (España)
Science and Technology Facilities Council (UK)
We explore the effects of chain size on the structure and dynamics of ethylene glycol (EG) and poly(ethylene oxide) (PEO) intercalated in graphite oxide (GO). To this end, EG as well as a PEO series of increasing chain length have been studied by means of high-resolution inelastic neutron spectroscopy. The neutron experiments are complemented by X-ray diffraction, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and Raman scattering. We find that EG is accommodated in a layer of thickness ∼3 Å within the GO substrate and adopts a preferential, yet largely disordered, gauche conformation. Longer PEO chains give rise to a layer thickness in the range ∼3.0-3.4 Å characterized by planar zigzag (trans-trans-trans) conformations. Moreover, we observe a strong reduction of vibrational motions for the confined EG and polymer phases, as clearly evidenced by the disappearance, shift, and/or broadening of mode-specific inelastic neutron scattering spectral features, as well as by the complete suppression of crystallization. All of these effects are surprisingly insensitive to the length of the PEO chains. © 2012 American Chemical Society.
2014-09-09T07:59:15Z
2014-09-09T07:59:15Z
2012
2014-09-09T07:59:15Z
artículo
Macromolecules 45(7): 3137-3144 (2012)
http://hdl.handle.net/10261/101836
10.1021/ma202655f
http://dx.doi.org/10.13039/501100003339
http://dx.doi.org/10.13039/501100000271
http://dx.doi.org/10.13039/501100003086
eng
closedAccess
American Chemical Society