羧甲基纤维素钠/蒙脱土悬浮体系的流变性能及其影响因素

考察了蒙脱土(MT)质量分数(w)、羧甲基纤维素钠(CMC)/MT质量比(R)、电解质(NaCl、MgCl2和AlCl3)、pH值和温度对MT或CMC/MT悬浮体系流变性能和触变性的影响。 结果表明，随w增加，纯MT悬浮体系的流体类型由近牛顿流体向塑型流体变化，触变类型则由无触变、正触变向复合触变性转变；而CMC/MT悬浮体系仍保持MT体系的正触变塑型流体特征，但屈服值τ0和稠度指数K增加，滞后环面积S和电动电势|ζ|先增加后减小，表现出同步变化。 电解质和实验温度均不改变CMC/MT悬浮体系的正触变性塑型流体特征，但电解质使τ0和K增加，而温度增加使τ0和K减小。 随介质pH值的增加，CMC/MT体系由负触变性变为正触变性，|ζ|增大，S先增加后减小，且在pH=8.46时达到最大。

Rheologic Property and Influencing Factors of Sodium Carboxymethyl Cellulose/Montmorillonite Suspension

In order to unveil the rheological properties of suspensions of montmorillonite(MT) and its mixture with sodium carboxymethyl cellulose(CMC)/MT, the effects of the mass fraction w of MT, mass ratio R of CMC to MT, electrolyte, pH and experimental temperature on such properties have been systematically studied. When w(MT) was increased from 1.0% to 3.0%, pure MT suspension changed from Newtonian-like fluid to plastic one, and the thixotropic type changed from non-thixotropy to positive thixotropy and then a complex one. For CMC/MT plastic suspension, the increase of R(fixing w(MT)=2.0% in all the systems) would cause the yield value(τ0) and consistency coefficient(K) to increase as well. The hysteresis loop area(S) increased initially and then decreased, which was accompanied with a synchronous variation of the absolute zeta potential value(|ζ|). The plastic and thixotropic characters of CMC/MT suspension could not be altered by either the electrolytes or experimental temperature investigated. But the yield value τ0 and consistency coefficient K would increase with the increase of electrolyte(NaCl, MgCl2 and AlCl3) concentrations or the decrease of experimental temperature. With the increase of pH value of CMC/MT suspension, its thixotropic type was transformed from negative into positive and the |ζ| incresesd, meanwhile the S firstly increased and then decreased and its maximum value was reached at pH=8.46.