微晶纤维素电流变液在挤压流中的粘弹性

测量了微晶纤维素/蓖麻油悬浮体构成的电流变液在挤压流中的动态粘弹性.给出了平行于电 场方向的储能模量G′和损耗模量G″对电场和应变幅度的依赖关系.实验显示，当电场超过 临界电场后，随着应变幅度增加, 电流变液的粘弹性从线性变到非线性，电流变液出现了应 变导致的“类固体”和流体之间的转变过程. 还研究了应变幅度和振荡频率对电流变液粘弹性非线性的影响. 关键词： 电流变液 挤压流 粘弹性

SQUEEZE FLOW VISCOELASTICITY OF ELECTRORHEOLOGICAL FLUIDS BASED ON MICROCRYSTAL LINE CELLULOSE

Dynamic viscoelasticity of electrorheological fluids based on microcrystalline c ellulose/castor oil suspensions was experimentally investigated in squeeze flow. The dependence of storage modulus G′and loss modulus G″parallel to external e lectric field on electric fields and strain amplitudes is presented. The experim ents show that, when external electric field is higher than the critical field, the viscoelasticity of the ER fluids converts from linear to nonlinear, and the ER fluids transfer from solid-like state to fluid state with the growth of strai n amplitude. The influences of strain amplitude and oscillatory frequency on the nonlinearity of viscoelasticity were also studied.