Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 26, 2004
Publication Date: August 26, 2004
Citation: Kim, S., Xu, J., Biswas, A., Willett, J.L. 2004. Shear-induced aggregate formation in starch solutions [abstract]. American Chemical Society Abstracts. Paper No.788013. Technical Abstract: Since Dintzis et al. reported shear-thickening behavior and shear-induced pattern formation in semidilute starch solutions for the first time in 1995, considerable efforts have been made to understand the reason for these behaviors. While the shear-thickening behavior was found to be a breaking procedure of highly concentrated gel-like structures dispersed in dilute starch solutions, the reason for shear-induced pattern formation has not been understood. The pattern formation, observed when the solution is exposed to higher shear rate, is irrelevant to shear-thickening behavior and is not observed below a certain critical threshold shear rate. In this presentation, we report that the shear-induced pattern formation is caused by the aggregation of starch remnants in the solution. A universal behavior of shear-induced aggregate formation as functions of shear time and shear rate will be demonstrated.