Title :
Determination of the water absorption kinetics in hydrogels by SLAM
Author :
Luprano, V.A.M. ; Montagna, G. ; Maffezzoli, A.
fDate :
Oct. 31 1994-Nov. 3 1994
Abstract :
The water absorption time from Poly(HEMA) is calculated studying the relative changes in the ultrasonic attenuation by a SLAM system. Acoustical images performed at 30 MHz of Poly(HEMA) gel during water absorption showed the ultrasonic attenuation increase with the time. This phenomena is attributed to an increase in the reflection of the acoustic waves that cross interface planes with different acoustic impedance produced by the change in the structural phase. When no more interface planes exist the attenuation drops to lower values and after a relaxation time during which the microporosities disappear and the structure becomes unstressed, the attenuation arrives at the lowest value due to the lower acoustic impedance of the saturated hydrogel structure
Keywords :
acoustic impedance; acoustic microscopy; gels; solid-liquid transformations; sorption; ultrasonic absorption; ultrasonic imaging; SLAM system; acoustic impedance; acoustic wave reflection; acoustical images; hydrogels; interface planes; poly(HEMA) gel; ultrasonic attenuation; water absorption kinetics; Absorbing media; Acoustic imaging/mapping; Acoustic microscopy;
Conference_Titel :
Ultrasonics Symposium, 1994. Proceedings., 1994 IEEE
Conference_Location :
Cannes, France
Print_ISBN :
0-7803-2012-3
DOI :
10.1109/ULTSYM.1994.401762
