Cao Xue-Zheng, Merlitz Holger, Wu Chen-Xu, Ungar Goran, Sommer Jens-Uwe
Department of Physics, Zhejiang Sci-Tech University, Hangzhou 310018, P.R. China.
Department of Physics and ITPA, Xiamen University, Xiamen 361005, P.R. China and Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany.
Nanoscale. 2016 Apr 7;8(13):6964-8. doi: 10.1039/c5nr08576d.
The properties of polymer-nanoparticle (NP) mixtures significantly depend on the dispersion of the NPs. Using molecular dynamics simulations, we demonstrate that, in the presence of polymer-NP attraction, the dispersion of NPs in semidilute and concentrated polymers can be stabilized by increasing the polymer concentration. A lower polymer concentration facilitates the aggregation of NPs bridged by polymer chains, as well as a further increase of the polymer-NP attraction. Evaluating the binding of NPs through shared polymer segments in an adsorption blob, we derive a linear relationship between the polymer concentration and the polymer-NP attraction at the phase boundary between dispersed and aggregated NPs. Our theoretical findings are directly relevant for understanding and controlling many self-assembly processes that use either dispersion or aggregation of NPs to yield the desired materials.
聚合物-纳米颗粒（NP）混合物的性质很大程度上取决于纳米颗粒的分散情况。通过分子动力学模拟，我们证明，在聚合物与纳米颗粒存在吸引力的情况下，增加聚合物浓度可使纳米颗粒在半稀和浓聚合物中的分散得以稳定。较低的聚合物浓度会促进由聚合物链桥接的纳米颗粒聚集，以及聚合物与纳米颗粒吸引力的进一步增加。通过评估吸附团块中共享聚合物链段的纳米颗粒结合情况，我们得出了聚合物浓度与分散和聚集纳米颗粒相界处聚合物-纳米颗粒吸引力之间的线性关系。我们的理论发现对于理解和控制许多利用纳米颗粒分散或聚集来制备所需材料的自组装过程具有直接意义。
