A chemical hydrogel based on telechelic poly(vinyl alcohol) and a physical synergic hydrogel, xanthan-glucomannan, were studied by means of dynamic light scattering technique. Two different nonergodic methods. due to Pusey et al. (Physica A 157 (1989) 705, Phys. Rev. A 42 (1990) 2161) and Xue et al. (Phys. Rev. A 46 (1992) 6550). were used to obtain the correct dynamic structure factors f(q,t). Good agreement between the results obtained with the two procedures was found. The behavior of the f(q,t) for different q vectors is consistent with the hypothesis that the nonfluctuating component in the scattered light is not due to microscopic heterogeneities but to restricted motion of the scatterers. The model of Krall et al. (Phys, Rev. Lett. 80 (1998) 778, Physica A 235 (1997) 19) was successfully applied to both hydrogels to extract the characteristic parameters of the network from the f(q,t) functions. (C) 2002 Published by Elsevier Science B.V.
Chemical and physical hydrogels: two casesystems studied by quasi elastic light scattering / Bordi, Federico; G., Paradossi; C., Rinaldi; Ruzicka, Barbara. - In: PHYSICA. A. - ISSN 0378-4371. - 304:1-2(2002), pp. 119-128. (Intervento presentato al convegno International Conference on Scattering Studies of Mesoscopic Scale Structure and Dynamics in Soft Matter tenutosi a MESSINA, ITALY nel NOV 22-25, 2000) [10.1016/s0378-4371(01)00537-4].
Chemical and physical hydrogels: two casesystems studied by quasi elastic light scattering
BORDI, FEDERICO;RUZICKA, BARBARA
2002
Abstract
A chemical hydrogel based on telechelic poly(vinyl alcohol) and a physical synergic hydrogel, xanthan-glucomannan, were studied by means of dynamic light scattering technique. Two different nonergodic methods. due to Pusey et al. (Physica A 157 (1989) 705, Phys. Rev. A 42 (1990) 2161) and Xue et al. (Phys. Rev. A 46 (1992) 6550). were used to obtain the correct dynamic structure factors f(q,t). Good agreement between the results obtained with the two procedures was found. The behavior of the f(q,t) for different q vectors is consistent with the hypothesis that the nonfluctuating component in the scattered light is not due to microscopic heterogeneities but to restricted motion of the scatterers. The model of Krall et al. (Phys, Rev. Lett. 80 (1998) 778, Physica A 235 (1997) 19) was successfully applied to both hydrogels to extract the characteristic parameters of the network from the f(q,t) functions. (C) 2002 Published by Elsevier Science B.V.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
