物理化学学报 >> 2018, Vol. 34 >> Issue (10): 1144-1150.doi: 10.3866/PKU.WHXB201802122

所属专题: 材料科学的分子模拟

论文 上一篇    下一篇

聚合物接枝Janus纳米片形变的耗散粒子动力学研究

陆腾1,周永祥1,2,郭洪霞1,2,*()   

  1. 1 中国科学院化学研究所,北京分子科学国家实验室,高分子科学与材料联合实验室,高分子物理与化学国家重点实验室,北京 100190
    2 中国科学院大学, 北京 100049
  • 收稿日期:2018-01-03 发布日期:2018-04-13
  • 通讯作者: 郭洪霞 E-mail:hxguo@iccas.ac.cn
  • 基金资助:
    国家自然科学基金(21174154);国家自然科学基金(21204094);国家自然科学基金(50930002);国家自然科学基金(20874110);国家自然科学基金(20674093);国家重点基础研究发展计划(973)(2014CB643601)

Deformation of Polymer-Grafted Janus Nanosheet: A Dissipative Particle Dynamic Simulations Study

Teng LU1,Yongxiang ZHOU1,2,Hongxia GUO1,2,*()   

  1. 1 Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Sciences and Materials, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
    2 University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2018-01-03 Published:2018-04-13
  • Contact: Hongxia GUO E-mail:hxguo@iccas.ac.cn
  • Supported by:
    the National Nature Science Foundation of China(21174154);the National Nature Science Foundation of China(21204094);the National Nature Science Foundation of China(50930002);the National Nature Science Foundation of China(20874110);the National Nature Science Foundation of China(20674093);National Basic Research Program of China (973)(2014CB643601)

摘要:

由于在检测、药物输运、分子马达等领域具有广阔的应用前景,二维柔性响应Janus材料受到了广泛的关注。但遗憾的是,这些二维材料的响应形变的分子机理仍不明确。基于此,我们采用介观尺度的耗散粒子动力学模拟方法系统研究了Janus纳米片两侧接枝不同长度和不同溶剂相容性的高分子链对Janus纳米片形变的影响。我们发现由于构象熵和混合焓的共同作用,通过对接枝链长度和溶剂相容性的调整,Janus纳米片可以形成如反相包覆、信封装包覆和碗状等新奇的结构。我们的理论结果首次提供了对二维柔性Janus材料可控形变的基本认识,并预报了设计合成新型Janus纳米器件在药物和生物医学领域的潜在应用。

关键词: Janus纳米材料, 聚合物, 两亲性复合材料, 形态调控, 耗散粒子动力学模拟

Abstract:

Because of broad potential applications in sensing, drug delivery, and molecular motors, two-dimensional (2D), flexible, responsive Janus materials have attracted considerable interest recently in many fields. Unfortunately, the molecular-level responsive deformation of these 2D Janus nanomaterials is still not clearly understood. Hence, investigating the influence factor and responsiveness of the deformation of the 2D flexible responsive Janus nanomaterials should be helpful to deepen our understanding of the deformation mechanism and may provide valuable information in the design and synthesis of novel functional 2D Janus nanomaterials. Therefore, a mesoscopic simulation method, dissipative particle dynamics simulation, based on coarse-grained models, is employed in this work to systematically investigate the effect of the chain length difference between grafted polymers within two compartments of each individual Janus nanosheet and the effect of solvent selectivity difference of these two compartments on the deformation of the polymer-grafted Janus nanosheet. Although the coarse-grained model within this simulation is relatively crude, it is still valid to provide a qualitative image of the deformation of the polymer-grafted Janus nanosheet. Furthermore, we find two basic principles: (1) with increasing length difference between grafted polymers on the two opposite surfaces, the nanosheet will bear an entropy-driven deformation with increasing curvature; (2) the solvent will preferentially wet the polymer layer with better compatibility, and such a swelling effect may also provide a driving force for the deformation process. Owing to the interplay of conformational entropy and mixing enthalpy, the equilibrium structures of the polymer-grafted Janus nanosheet result in several interesting structures, such as a tube-like structure with a hydrophobic outer surface, an envelope-like structure, and a bowl-like structure, with tuning of the chain length and solvent compatibility of grafted polymers. Additionally, an unusually tube-like structure with a hydrophobic outer surface has been observed for a relatively weak solvent selectivity, which may provide us a novel method to transfer materials into the incompatible environment and therefore has potential applications in many areas, such as controllable drug delivery and release, and industrial and medical detection. Our theoretical results first provide a fundamental insight into the controllable deformation of the flexible Janus nanosheet, which can then help in the design and synthesis of novel Janus nanodevices for potential applications in pharmaceuticals and biomedicine. Bearing the limited of the computational capabilities, our model Janus nanosheets are relatively small, which are not direct mappings from real system. We hope that a systematic simulation study on this topic would be possible soon with the rapid developments in computer technology and simulation methods, and this would provide an exhaustive and universal methodology to guide experimental studies and applications.

Key words: Janus nanomaterial, Polymer, Amphiphilic composites, Morphology control, Dissipative particle dynamics simulation

MSC2000: 

  • O647