TY - JOUR
T1 - Brillouin-scattering study of hyaluronic acid
T2 - Dynamic coupling with the water of hydration and phase transitions
AU - Lee, S. A.
AU - Flowers, M. R.
AU - Oliver, W. F.
AU - Rupprecht, A.
AU - Lindsay, Stuart
PY - 1993/1/1
Y1 - 1993/1/1
N2 - Brillouin spectra have been measured from wet-spun films of Li and Na hyaluronate (NaHA) between 0% and 93% relative humidity (RH). The speed of sound is very high (about 5 km/s) in both Li and NaHA films at low values of RH. The Brillouin spectra show substantial coupling between the longitudinal-acoustic phonons and a relaxation mode of the water of hydration. A coupled-modes model is used to interpret these data. This analysis shows that the relaxation time of the water of hydration (about 50 ps) is constant over the range of hydration. The microscopic coupling constant also appears to be independent of hydration. Between 84% and 88% RH, the uncoupled phonon frequency for both Li and NaHA is found to drop by 40%, and 25% for phonons propagating in the parallel and perpendicular directions, respectively, indicative of a phase transition.
AB - Brillouin spectra have been measured from wet-spun films of Li and Na hyaluronate (NaHA) between 0% and 93% relative humidity (RH). The speed of sound is very high (about 5 km/s) in both Li and NaHA films at low values of RH. The Brillouin spectra show substantial coupling between the longitudinal-acoustic phonons and a relaxation mode of the water of hydration. A coupled-modes model is used to interpret these data. This analysis shows that the relaxation time of the water of hydration (about 50 ps) is constant over the range of hydration. The microscopic coupling constant also appears to be independent of hydration. Between 84% and 88% RH, the uncoupled phonon frequency for both Li and NaHA is found to drop by 40%, and 25% for phonons propagating in the parallel and perpendicular directions, respectively, indicative of a phase transition.
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U2 - 10.1103/PhysRevE.47.677
DO - 10.1103/PhysRevE.47.677
M3 - Article
AN - SCOPUS:35949006334
VL - 47
SP - 677
EP - 683
JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
SN - 1539-3755
IS - 1
ER -