Hao Qing-Hai, Cheng Jie, Yang Fan, Tan Hong-Ge
College of Science, Civil Aviation University of China Tianjin 300300 China
RSC Adv. 2022 Jul 7;12(31):19726-19735. doi: 10.1039/d2ra00867j. eCollection 2022 Jul 6.
Self-assembled structure of polymer grafted nanoparticles is an interesting and growing subject in the field of hybrid electronics and high energy density materials. In light of this, the self-assembled morphologies of polyelectrolyte (PE) sparsely grafted nanoparticles tuned by oppositely charged matrix chains are studied using molecular dynamics simulations. Our focus is to elucidate the effect of matrix chain polymerization on modulating the stretching properties of tethered PE layers, on the self-assembled structuring of nanoparticles. Through varying the matrix chain length and stiffness as well as electrostatic interaction strength, rich phase behaviors of PE coated nanoparticles are predicted, including spherical micelle-like structures being preferred with short matrix chains and percolating network morphologies favored with long matrix chains, which is more pronounced with an enhanced matrix chain rigidness. To pinpoint the mechanisms of self-assembled structure formation, the thickness of grafted layers, the gyration radius of tethered chains, and pair correlation functions between nanoparticles are analyzed carefully. Additionally, electrostatic correlations, manifested as the bridging matrix chains, are examined by identifying three states of matrix PE chains. Our simulation results may be useful for designing smart polymer nanocomposites based on PE coated nanoparticles.
聚合物接枝纳米粒子的自组装结构是混合电子学和高能量密度材料领域中一个有趣且不断发展的课题。鉴于此，利用分子动力学模拟研究了由带相反电荷的基质链调控的聚电解质（PE）稀疏接枝纳米粒子的自组装形态。我们的重点是阐明基质链聚合对调节接枝PE层的拉伸性能以及纳米粒子自组装结构的影响。通过改变基质链长度、刚度以及静电相互作用强度，预测了PE包覆纳米粒子丰富的相行为，包括短基质链时更倾向于形成球形胶束状结构，长基质链时更有利于形成渗流网络形态，且随着基质链刚性增强这种现象更明显。为了确定自组装结构形成的机制，仔细分析了接枝层的厚度、接枝链的回转半径以及纳米粒子之间的对关联函数。此外，通过识别基质PE链的三种状态来研究表现为桥连基质链的静电相关性。我们的模拟结果可能有助于设计基于PE包覆纳米粒子的智能聚合物纳米复合材料。
