Effect of Particle/Polymer Number Ratio on the Structure and Dynamics of Complex between Large Polymer and Nanoparticle
Effect of Particle/Polymer Number Ratio on the Structure and Dynamics of Complex between Large Polymer and Nanoparticle
复制标题
颗粒/聚合物数量比对大聚合物与纳米颗粒复合物结构和动力学的影响
DOI：
10.1016/j.colsurfa.2016.07.080
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Qiu Dong
中科院分区：
文献类型：
--
作者：
Yan Feng;Ye Lei;Qiu Dong
研究了在固定聚合物浓度下颗粒/聚合物数量比对颗粒-聚合物复合物的结构和动力学的影响。使用聚环氧乙烷 (PEO,Mv= 1,000,000 g mol−1,Rh∼39 nm) 水溶液和胶体二氧化硅分散体 (Rh∼10 nm) 的混合物作为模型。通过添加二氧化硅颗粒，二氧化硅-PEO复合物的零剪切粘度和Rhof随着颗粒/聚合物数量比的增加而增加。当 PEO 线圈被二氧化硅颗粒饱和时，达到最大零剪切粘度。此后，观察到零剪切粘度和Rh 降低。 SAXS 结果表明，在 PEO 链被二氧化硅颗粒饱和之前，PEO 对颗粒间相关性有很大影响，然而，当引入更多二氧化硅颗粒时，这种影响减弱。可逆桥联相互作用和颗粒间静电斥力被认为是导致零剪切粘度和流体动力学尺寸变化的主要因素，并根据混合物中二氧化硅颗粒的空间分布提出了一种初步机制。
The effect of particle/polymer number ratio on the structure and dynamics of particle-polymer complexes at a fixed polymer concentration has been investigated. Mixtures of poly(ethylene oxide) (PEO,Mv= 1,000,000 g mol−1,Rh∼39 nm) aqueous solution and colloidal silica dispersion (Rh∼10 nm) were used as models. By adding silica particles, both zero-shear viscosity andRhof the silica-PEO complexes increased with particle/polymer number ratio. The maximum zero-shear viscosity was reached when the PEO coils were saturated by silica particles. After that, a decrease in zero-shear viscosity andRhwas observed. SAXS results showed that PEO had a great effect on the inter-particle correlations before the PEO chains were saturated with silica particles, however, this effect diminished when even more silica particles were introduced. The reversible bridging interaction and inter-particle electrostatic repulsion were identified as the major factors accounting for the change in zero-shear viscosity and hydrodynamic size, and a tentative mechanism was proposed based on the spatial distribution of silica particles in the mixtures.