TY - JOUR
TI - Phonon propagation in ordered diblock copolymer solutions
AU - Tommaseo, G.
AU - Penciu, R.S.
AU - Fytas, G.
AU - Economou, E.N.
AU - Hashimoto, T.
AU - Hadjichristidis, N.
JO - Macromolecules
PY - 2004
VL - 37
TODO - 13
SP - 5006-5010
PB - 
SN - 0024-9297, 1520-5835
TODO - 10.1021/ma0496246
TODO - Annealing;  Block copolymers;  Brillouin scattering;  Dispersions;  Elastic waves;  Light scattering;  Phonons;  Rayleigh scattering;  Refractive index;  Solutions;  Transmission electron microscopy;  Vectors;  X ray scattering, Elastic constants;  Grain orientation;  Microphase morphology;  Sensitive index, Macromolecules
TODO - High-resolution inelastic light scattering was employed to measure the dispersion relations for the acoustic excitations in ordered concentrated solutions of poly(styrene)-block-poly(isoprene) copolymers with both symmetric and asymmetric composition and large spacing (220-415 nm). The morphology is manifested in the rich phonon spectrum recorded for different scattering wave vectors q in the range 0.003-0.034 nm-1. The experimental ωa,(q) of the sth branch is directly compared with the theoretical dispersion from band structure calculations performed for different directions of q in the reciprocal lattice of lamellar and cylindrical periodic structures. The dispersion relations turn out to be a sensitive index of the microphase morphology and the grain orientation.
ER -