SiO2纳米粒子对受限流场下聚异丁烯/聚二甲基硅氧烷共混物相形态的影响

利用显微-光学剪切联用系统构造受限剪切环境,探讨了少量不同表面性质的SiO2纳米粒子的加入对聚异丁烯(PIB)/聚二甲基硅氧烷(PDMS)不相容共混体系分散相形态演变过程的影响.研究结果表明,少量疏水性SiO2纳米粒子的加入可抑制分散相液滴的凝聚,从而抑制珍珠链状及纤维状等超级相形态的形成,使共混物表现为近似本体流体的...

Effect of Silica Nanoparticles on the Morphology of Immiscible PIB/PDMS Blends in Confined Shear Flow

The morphology development in immiscible polymer blends under confined shear flow(such as in the field of micro-processing) usually differs significantly to that observed in bulk conditions. In this work, the effect of silica nanoparticles with different surface properties on the morphology development of immiscible polyisobutylene(PIB)/polydimethylsiloxane(PDMS)(10:90) blends under confined shear flow was investigated. The confined environment was created by an optical-shear cell united system. It was found that the addition of only a very small amount(0.2%) of hydrophobic SiO2 nanoparticles could suppress the coalescence of dispersed droplets effectively and thus decreased the confinement degree of droplets. As a result, the formation of the superstructures(such as pearl necklaces and strings), as presented in the pure PIB/PDMS blends, were prevented and the blends displayed a near bulk behavior. On the contrary, the blends with the addition of small amount of hydrophilic SiO2 nanoparticles still formed superstructures of dispersed droplets under shear flow. Bulk behavior of dispersed phase could only be obtained with higher concentration of the hydrophilic SiO2 nanoparticles and under higher shear rate.