Influence of particle modulus on the rheological properties of agar microgel suspensions
Influence of particle modulus on the rheological properties of agar microgel suspensions
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DOI：
10.1122/1.1795193
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发表时间：
2004-11-01
影响因子：
3.3
通讯作者：
Stokes, JR
中科院分区：
文献类型：
--
作者：
Adams, S;Frith, WJ;Stokes, JR
已经测量了一系列琼脂微凝胶颗粒的高相体积悬浮液的线性粘弹性和稳定剪切流动性质，并且发现其取决于颗粒的变形性（或模量）。使用0.5- 5wt%范围内的琼脂浓度，得到跨越2.4-185 kPa的颗粒模量范围。在增加颗粒模量时，在相体积高于最大堆积的悬浮液中，储能模量增加两个数量级，尽管损耗角正切（tan δ）也由于增加的粘性耗散而增加。在高剪切应力下的悬浮液的流动特性也表现出显着的差异，由于改变颗粒刚度。发现含有最硬颗粒的悬浮液在高应力下显示出有限的剪切增稠行为证据，而含有最软颗粒的悬浮液则继续剪切变稀。对于具有中等刚性颗粒的悬浮液，观察到粘度的高剪切平台。对于相同程度的空间填充，含有较硬颗粒的悬浮液也具有相当高的粘度。经验表达式连接的粘弹性和流动性能的颗粒模量已经推导出来。(C)2004流变学学会。
The linear viscoelastic and steady shear flow properties of high phase volume suspensions of a range of agar microgel particles have been measured and are found to depend upon the deformability (or modulus) of the particles. Agar concentrations in the range 0.5-5 wt % are utilized, giving a range of particle modulus spanning 2.4-185 kPa. On increasing the particle modulus, in suspensions with phase volumes above maximum packing, the storage modulus increases by two orders of magnitude although the loss tangent (tan delta) also increases due to increasing viscous dissipation. The flow properties of the suspensions at high shear stresses also showed significant differences due to changing particle rigidity. The suspensions containing the hardest particles are found to display limited evidence of shear-thickening behavior at high stresses, while those containing the softest particles continue to shear thin. A high-shear plateau in the viscosity is observed for suspensions with particles of medium rigidity. The suspensions containing the stiffer particles also have a considerably higher viscosity for the same degree of space filling. Empirical expressions linking the viscoelastic and flow properties to the particle modulus have been derived. (C) 2004 The Society of Rheology.