Concentrated suspensions of Brownian and non-Brownian particles display distinctive rheological behavior highly dependent on shear rate and shear stress. Cornstarch suspensions, composed of starch particles from corn plants, served as a model for concentrated non-Brownian suspensions, demonstrating discontinuous shear thickening (DST) and dynamic shear jamming (SJ). However, starch particles from other plant sources have not yet been investigated, despite their different sizes and shapes. This study is focused on the evaluation of the effects of the structural parameters of starch particles by preparing concentrated suspensions of starch particles from 13 different plants at particle fractions of 25–50% and their rheological behavior through steady shear, pull-out, and ball-drop tests. Starch particles can be roughly classified as polygonal and ellipsoidal. The DST and SJ behavior typically reported for concentrated cornstarch suspensions were confirmed for other starch particles in both particle groups. The ball-drop test demonstrated excellent shock absorption properties for 11 concentrated suspensions of starch particles, except for sago palms. In the case of concentrated suspensions of starch particles, the particle fraction and shear applied were the dominant factors that significantly affected the rheological behavior, whereas the particle shape was not a primary contributor. The findings of this study drive further investigation on the effect of liquid and particle surface properties in concentrated particle suspensions on DST and SJ behaviors.

中文翻译：

---

Starches 致密颗粒悬浮液的流变特性：剪切增稠、剪切干扰和减震特性


布朗颗粒和非布朗颗粒的浓缩悬浮液表现出独特的流变行为，高度依赖于剪切速率和剪切应力。玉米淀粉悬浮液由来自玉米植物的淀粉颗粒组成，用作浓缩非布朗悬浮液的模型，表现出不连续剪切增稠 （DST） 和动态剪切干扰 （SJ）。然而，来自其他植物来源的淀粉颗粒尽管大小和形状不同，但尚未得到研究。本研究的重点是通过稳定剪切、拉出和落球测试制备来自 13 种不同植物的淀粉颗粒（颗粒分数为 25-50%）的浓缩悬浮液及其流变行为，从而评估淀粉颗粒结构参数的影响。淀粉颗粒大致可分为多边形和椭球体。通常报告的浓缩玉米淀粉悬浮液的 DST 和 SJ 行为在两个颗粒组中的其他淀粉颗粒中得到证实。落球测试表明，除西米棕榈外，11 种浓缩淀粉颗粒悬浮液具有出色的减震性能。在淀粉颗粒的浓缩悬浮液的情况下，颗粒分数和施加的剪切是显着影响流变行为的主要因素，而颗粒形状不是主要贡献者。本研究的结果推动了对浓缩颗粒悬浮液中液体和颗粒表面特性对 DST 和 SJ 行为影响的进一步研究。