摘要：本文提出一种高效的热力学方法，通过将多壁碳纳米管（MWCNTs）精确定位于共连续PS/PMMA共混物的界面，设计具有超低逾渗阈值的导电聚合物复合材料。MWCNTs界面分布的实现归因于PS与MWCNT表面之间π-π相互作用和PMMA与MWCNT表面羧基之间偶极-偶极相互作用的平衡。研究发现，当MWCNT表面羧基含量约为0.73 wt%时，可精确平衡π-π相互作用与偶极-偶极相互作用，从而将MWCNTs很好地控制在PS/PMMA界面。由于所有MWCNTs精确定位于连续界面并构筑逾渗导电通路，该类导电聚合物复合材料的逾渗阈值从1.81 wt%（MWCNTs/PS）或1.46 wt%（MWCNTs/PMMA）降至0.017 wt%，是目前极低的逾渗阈值。更重要的是，该方法可方便地推广到其他涉及π-π相互作用和偶极-偶极相互作用的体系。

Abstract：In the current study, we propose an efficient thermodynamic method to precisely control multi-walled carbon nanotubes (MWCNTs) at the interface of a co-continuous PS/PMMA blend to design conductive polymer composites with ultralow percolation threshold. The achievement of the interfacial distribution of MWCNTs is attributed to the balance of π-π interactions between PS and MWCNT surfaces and dipole-dipole interactions between PMMA and carboxyl groups on MWCNT surfaces. It is found that MWCNTs can be well controlled at PS/PMMA interface when carboxyl content on MWCNT surfaces is ca. 0.73 wt%, which can exactly make a balance between π-π interactions and dipole-dipole interactions. Because all the MWCNTs are precisely controlled at the continuous interface to build a percolated conductive pathway, the percolation threshold of this type of conductive polymer composite is lowered from 1.81 wt% (MWCNTs/PS) or 1.46 wt% (MWCNTs/PMMA) to 0.017 wt%, which is an ultralow percolation threshold so far. More importantly, this method can be easily extended to other systems involved with π-π interactions and dipole-dipole interactions.

论文链接：https://doi.org/10.1016/j.carbon.2016.12.048