TY - JOUR
T1 - Rheological Properties of Aging Thermosensitive Suspensions
AU - Purnomo, Eko H
AU - van den Ende, Dirk
AU - Mellema, Jorrit
AU - Mugele, Frieder
PY - 2007
Y1 - 2007
N2 - Aging observed in soft glassy materials inherently affects the rheological properties of these systems and has been described by the soft glassy rheology (SGR) model [S. M. Fielding et al., J. Rheol. 44, 323 (2000)]. In this paper, we report the measured linear rheological behavior of thermosensitive microgel suspensions and compare it quantitatively with the predictions of the SGR model. The dynamic moduli [G[prime](omega,t) and G[double-prime](omega,t)] obtained from oscillatory measurements are in good agreement with the model. The model also predicts quantitatively the creep compliance J(t−tw,tw), obtained from step stress experiments, for the short time regime [(t−tw)<tw]. The relative effective temperature [script X]/[script X]g obtained from both the oscillatory and the step stress experiments is indeed less than 1 ([script X]/[script X]g<1) in agreement with the definition of aging. Moreover, the elasticity of the compressed particles (Gp) increases with increased compression, i.e., the degree of hindrance and consequently also the bulk elasticity (G[prime] and 1/J) increases with the degree of compression.
AB - Aging observed in soft glassy materials inherently affects the rheological properties of these systems and has been described by the soft glassy rheology (SGR) model [S. M. Fielding et al., J. Rheol. 44, 323 (2000)]. In this paper, we report the measured linear rheological behavior of thermosensitive microgel suspensions and compare it quantitatively with the predictions of the SGR model. The dynamic moduli [G[prime](omega,t) and G[double-prime](omega,t)] obtained from oscillatory measurements are in good agreement with the model. The model also predicts quantitatively the creep compliance J(t−tw,tw), obtained from step stress experiments, for the short time regime [(t−tw)<tw]. The relative effective temperature [script X]/[script X]g obtained from both the oscillatory and the step stress experiments is indeed less than 1 ([script X]/[script X]g<1) in agreement with the definition of aging. Moreover, the elasticity of the compressed particles (Gp) increases with increased compression, i.e., the degree of hindrance and consequently also the bulk elasticity (G[prime] and 1/J) increases with the degree of compression.
KW - IR-59162
KW - METIS-240289
U2 - 10.1103/PhysRevE.76.021404
DO - 10.1103/PhysRevE.76.021404
M3 - Article
VL - 76
JO - Physical review E: covering statistical, nonlinear, biological, and soft matter physics
JF - Physical review E: covering statistical, nonlinear, biological, and soft matter physics
SN - 2470-0045
IS - 2
M1 - 0211404
ER -