| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 591764 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2016 | 7 Pages |
•A starch paste is subjected to squeeze flow.•The sample retains memory of loading history.•Complex modulus of the fluid on dynamic loading is also studied.•The system is modelled as a visco-elastic three parameter solid.•Generalised calculus is incorporated to reproduce observed oscillation in strain.
In this work gelatinised potato starch is shown to retain the memory of past loading history. It exhibits a visco-elastic response which does not depend solely on instantaneous conditions. A simple squeeze flow experiment is performed, where loading is done in two steps with a time lag τ∼ seconds between the steps. The effect on the strain, of varying τ is reproduced by a three element visco-elastic solid model. Complexity is introduced through a generalised calculus approach by incorporating a non-integer order time derivative in the viscosity equation. A strain hardening proportional to the time lag between the two loading steps is also incorporated. This model reproduces the three salient features observed in the experiment, namely – the memory effect, slight initial oscillations in the strain as well as the long-time solid-like response. Dynamic visco-elasticity of the sample is also reported.
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