Delayed slip after step strains in highly entangled polystyrene solutions
作者:
L. A. Archer,
Y.‐L. Chen,
R. G. Larson,
期刊:
Journal of Rheology
(AIP Available online 1995)
卷期:
Volume 39,
issue 3
页码: 519-525
ISSN:0148-6055
年代: 1995
DOI:10.1122/1.550710
出版商: The Society of Rheology
关键词: POLYSTYRENE;SOLUTIONS;SLIP FLOW;GLASS;FLOW STRESS;COUETTE FLOW;NON−NEWTONIAN FLOW;SHEAR PROPERTIES
数据来源: AIP
摘要:
Apparent slip within a few micrometers of a glass surface is visualized with a microscope using small glass spheres as tracers suspended in a highly entangled 20% solution of polystyrene of molecular weight 8.42 million, confined between glass plates in a plane Couette device. After step shears of 0.5–5 strain units, particles within a few micrometers of each surface move by 70–500 μm, enough to unload more than half of the imposed shear strain at intermediate strains. The slip displacement, when plotted logarithmically against time, show a peculiar ‘‘kink’’ in the vicinity of the ‘‘Rouse’’ time of 100 s, similar to the kink reported for the shear stress. These results show that the peculiar rheological properties reported for highly entangled solutions are produced by an effective slip phenomenon that occurs either at the wall or in a thin disentanglement layer near it.
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