Neutron scattering study of the dynamics of a a polymer melt under nanoscopic confinement

Krutyeva, M.; Su, Y.; Unruh, T.; Richter, D.; Colmenoro, J.; Mijangos, C.; Schneider, G. J.; Martin, J.; Arbe, A.

doi:10.1063/1.3258329

Journal Article

Neutron scattering study of the dynamics of a a polymer melt under nanoscopic confinement

Krutyeva, M.FZJ* ; Martin, J. ; Arbe, A. ; Colmenoro, J. ; Mijangos, C. ; Schneider, G. J.FZJ* ; Unruh, T. ; Su, Y.FZJ* ; Richter, D.FZJ*

2009
American Institute of Physics Melville, NY

The journal of chemical physics 131, 174901 (2009) [10.1063/1.3258329]

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Please use a persistent id in citations: http://hdl.handle.net/2128/19844 doi:10.1063/1.3258329

Abstract: Poly(ethylene oxide) confined in an anodic aluminum oxide solid matrix has been studied by different neutron scattering techniques in the momentum transfer (Q) range 0.2<or=Q=/Q/<or=1.9 A(-1). The cylindrical pores of the matrix present a diameter (40 nm) much smaller than their length (150 microm) and are parallel and hexagonally ordered. In particular, we investigated the neutron intensity scattered for two orientations of the sample with respect to the incident beam, for which the Q direction was either parallel or perpendicular to the pores for a scattering angle of 90 degrees . Diffuse neutron scattering at room temperature has shown that the aluminum oxide has amorphous structure and the polymer in the nanoporous matrix is partially crystallized. Concerning the dynamical behavior, for Q<1 A(-1), the spectra show Rouse-like motions indistinguishable from those in the bulk within the uncertainties. In the high-Q limit we observe a slowing down of the dynamics with respect to the bulk behavior that evidences an effect of confinement. This effect is more pronounced for molecular displacements perpendicular to the pore axis than for parallel displacements. Our results clearly rule out the strong corset effect proposed for this polymer from nuclear magnetic resonance (NMR) studies and can be rationalized by assuming that the interactions with the pore walls affect one to two adjacent monomer monolayers.

Keyword(s): J ; aluminium compounds (auto) ; anodes (auto) ; monolayers (auto) ; neutron diffraction (auto) ; nuclear magnetic resonance (auto) ; polymer melts (auto) ; polymers (auto)

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Physics, Atomic, Molecular & Chemical

Note: The European Commission, NMI3 Contract No. RII3-CT-2003-505925, supported the experiments. Financial support from NoE SoftComp (Contract No. NMP3-CT-2004-502235) is gratefully acknowledged. The authors are grateful to R. Kimmich and N. Fatkullin for experimental NMR data and helpful discussions, A. Arenas for the help in the Alumina templates preparation, O. Sanchez for the aluminum sputtering of the templates, and M. Brodeck for computer simulation data. Support from Donostia International Physics Center (DIPC) is also acknowledged as well as Project Nos. MAT2007-63681, MAT2008-1073, and IT-436-07 (GV), and the Spanish Ministerio de Educacion y Ciencia (Grant Nos. CSD2006-53 and FPU AP2005-1063).

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Appears in the scientific report 2009

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