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Distinctive Morphology Modifiers for Polymer Blends: Roles of Asymmetric Janus Nanoparticles during Phase Separation.
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2020-05-07 , DOI: 10.1021/acs.jpcb.0c02165
Qing Li 1 , Liquan Wang 1 , Jiaping Lin 1 , Zhanwen Xu 1
Affiliation  

Janus nanoparticles (JPs), which are anisotropic nanoparticles with multiple constituting parts, have been recognized as superior compatibilizers for polymer-blend-based nanocomposites. However, so far, most studies focused on the effects of symmetric JPs on the phase separation dynamics of polymer blends, while the roles of asymmetric JPs during phase separation remain unclear. In this work, the phase separation dynamics of symmetric blends compatibilized by JPs with various compositions was studied by using dissipative particle dynamics (DPD) simulations. It was found that the blends compatibilized by asymmetric JPs tend to undergo morphological transitions from bicontinuous networks to droplets-in-matrix structures at the late stage of phase separation, which is due to the influence of asymmetric JPs on the energetically favored curvature of the interfaces between polymer domains. Such a mechanism is absent for symmetric JPs and other compatibilizers (e.g., triblock copolymers and homogeneous particles) because they lack the unique combination of chemical asymmetry with the particulate nature like the asymmetric JPs. Moreover, it was observed that the asymmetric JPs can stably localize at the interfaces and act as efficient compatibilizers only when the fraction of the minor constituent part exceeds a critical value. These findings not only shed light upon the roles of asymmetric JPs as compatibilizers but also indicate a promising strategy for designing polymer-blend-based nanocomposites with tailor-made structures.

中文翻译:

聚合物共混物的独特形态改性剂:相分离过程中不对称Janus纳米粒子的作用。

Janus纳米粒子(JPs)是具有多个组成部分的各向异性纳米粒子,已被公认为是基于聚合物共混物的纳米复合材料的优异相容剂。然而,到目前为止,大多数研究集中在对称JPs对聚合物共混物相分离动力学的影响上,而在相分离过程中非对称JPs的作用仍不清楚。在这项工作中,通过使用耗散粒子动力学(DPD)模拟研究了JPs与各种成分相容的对称共混物的相分离动力学。发现不对称JP相容的共混物在相分离的后期会经历从双连续网络到液滴在基质中的形态转变,这是由于不对称JP对聚合物结构域之间界面的能效曲率的影响所致。对称JP和其他增容剂(例如三嵌段共聚物和均相颗粒)不存在这种机制,因为它们缺乏化学不对称性与颗粒性质(例如不对称JP)的独特组合。此外,已经观察到,仅当次要组成部分的分数超过临界值时,不对称JP才能稳定地定位在界面处并充当有效的相容剂。这些发现不仅阐明了不对称JP作为增容剂的作用,而且还表明了设计具有定制结构的基于聚合物共混物的纳米复合材料的有前途的策略。对称JP和其他增容剂(例如三嵌段共聚物和均相颗粒)不存在这种机制,因为它们缺乏化学不对称性与颗粒性质(例如不对称JP)的独特组合。此外,已经观察到,仅当次要组成部分的分数超过临界值时,不对称JP才能稳定地定位在界面处并充当有效的相容剂。这些发现不仅阐明了不对称JP作为增容剂的作用,而且还表明了设计具有定制结构的基于聚合物共混物的纳米复合材料的有前途的策略。对称JP和其他增容剂(例如三嵌段共聚物和均相颗粒)不存在这种机制,因为它们缺乏化学不对称性与颗粒性质(例如不对称JP)的独特组合。此外,已经观察到,仅当次要组成部分的分数超过临界值时,不对称JP才能稳定地定位在界面处并充当有效的相容剂。这些发现不仅阐明了不对称JP作为增容剂的作用,而且还表明了设计具有定制结构的基于聚合物共混物的纳米复合材料的有前途的策略。观察到,仅当次要组成部分的分数超过临界值时,不对称JP才能稳定地定位在界面上并充当有效的相容剂。这些发现不仅阐明了不对称JP作为增容剂的作用,而且还表明了设计具有定制结构的基于聚合物共混物的纳米复合材料的有前途的策略。观察到,仅当次要组成部分的分数超过临界值时,不对称JP才能稳定地定位在界面上并充当有效的相容剂。这些发现不仅阐明了不对称JP作为增容剂的作用,而且还表明了设计具有定制结构的基于聚合物共混物的纳米复合材料的有前途的策略。
更新日期:2020-05-07
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