硅微粉对剪切增稠液流变性能的影响

Effect of Silicon Powder on Rheological Property of Shear Thickening Fluid

以聚乙二醇为分散介质,二氧化硅作为第一分散相粒子,硅微粉作为第二分散相粒子制备增稠效果显著的新型复合剪切增稠液(STF)。基于PEG—SiO2基础体系,研究不同比例第二分散相粒子对新型体系的流变性能的影响并探讨其作用机理。结果表明:随着添加硅微粉含量的增加,剪切增稠效果大幅提升,临界剪切速率变小,最大黏度上升。但当第二分散相粒子比例达到3%后,临界剪切速率和最大黏度受其影响变小,其相应数值始终保持在0.21/s和2000Pa·s左右,外观由接近透明变得偏向灰色。

A new type of shear thickening fluid(STF)with outstanding shear thickening effect was successfully prepared by using polyethylene glycol(PEG)as dispersing medium,SiO2 particles(650 nm)as the first dispersed phase and silicon powder(5000 mesh)as the second dispersed phase.Based on the foundation system which were composed of PEG and SiO2,the influence of the second dispersed phase particles on the rheology properties of the new system was studied and the mechanism was discussed.The results show that with increasing silicon powder addition,the shear thickening effect becomes more obvious,and the critical shear rate becomes lower and the maximum viscosity higher.However,when the ratio of the second dispersing phase particles reaches 3%,the influence on the critical shear rate and maximum viscosity is reduced(almost no change),and the corresponding values remain at about 0.21/s and 2000 Pa·s,respectively.At the same time,the appearance of the shear thickening fluid transforms from transparent to gray.