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借助在线剪切-显微装置研究了简单剪切流场下疏水纳米二氧化硅(SiO2)粒子对聚二甲基硅氧烷/聚异丁烯(PDMS/PIB=90 wt%∶10 wt%)不相容共混物实时结构演变过程的影响.研究表明,分散相尺寸的大小及其分布由粒子含量和剪切速率共同决定.少量纳米SiO2的加入能够抑制PIB分散相的凝聚,分散相的尺寸随着纳米SiO2含量的增大而减小,并且呈现出双峰分布.但随着SiO2粒子含量的进一步增加,分散相尺寸的双峰分布现象逐渐消失.SiO2的加入还导致PIB分散相对剪切速率的依赖性降低.当SiO2粒子含量低于2.5wt%时,较高的剪切速率凝聚得到的分散相的尺寸较大;当SiO2粒子含量超过2.5 wt%后,低速和高速剪切速率下凝聚得到的分散相尺寸基本相同.粒子的包覆、分散相的破碎和凝聚是出现以上现象的根本原因.
Polydimethylsiloxane / polyisobutylene (PDMS / PIB = 90 wt%: 10 wt%) hydrophobized with hydrophobic nano-silica particles (SiO2) was studied by means of an on-line shear- The results show that the size and distribution of dispersed phase are determined by the content of particles and the shear rate.The addition of a small amount of nano-SiO2 can inhibit the aggregation of PIB dispersed phase, the size of dispersed phase With the increase of the content of nano-SiO 2, it decreases and exhibits a bimodal distribution, but with the increase of the content of SiO 2, the bimodal distribution of dispersed phase disappears gradually.The addition of SiO 2 also leads to the relative shear of PIB When the content of SiO2 particles is less than 2.5wt%, the size of dispersed phase obtained by higher shear rate coalescence is larger; when the content of SiO2 particles is more than 2.5wt%, the low and high shear rate Aggregate obtained dispersed phase size is basically the same.Particle coating, dispersed phase of the crushing and aggregation is the root cause of the above phenomenon.