Conductive filler/polymer composite foams (CPC) with micro-/nano-scale bubbles have attracted much attention due to their various advantages. Understanding the evolution of electrical behavior in CPC foams is important for their functional application. There have been many experimental investigations of the electrical behavior of CPC foams, but how the electrical conductivity varies with bubble growth is not fully understood. Here, a novel resistive network model based on Monte Carlo simulation to directly predict the electrical conductivity of CPC foams is reported. The model uses multiwalled carbon nanotubes (MWCNTs) as a conductive filler and considers both the intrinsic electrical conductivity of the nanotubes and the electron tunneling effect. The model predictions agreed very well with the experimental data for both the solid and foamed composites. The results showed that the percolation threshold and the conductivity are strongly affected by the relative sizes of MWCNT length and bubble diameter. At relatively low void fractions (up to ~20%), the growth of bubbles with size comparable to the MWCNT length increased the conductivity. Further growth of cells (>30%) resulted in a gradual decrease in the conductivity. This model can be used in the design and optimization of conductive foams.

具有微米级/纳米级气泡的导电填料/聚合物复合泡沫（CPC）由于其各种优点而备受关注。了解CPC泡沫中电行为的演变对于其功能应用很重要。已经进行了许多有关CPC泡沫的电学行为的实验研究，但尚未完全了解电导率如何随气泡的增长而变化。在此，报告了一种基于蒙特卡洛模拟的直接预测CPC泡沫电导率的新型电阻网络模型。该模型使用多壁碳纳米管（MWCNT）作为导电填料，并同时考虑了纳米管的固有电导率和电子隧穿效应。模型预测与固体和泡沫复合材料的实验数据非常吻合。结果表明，渗透阈值和电导率受MWCNT长度和气泡直径的相对大小的强烈影响。在相对较低的空隙率（最高约20％）下，尺寸与MWCNT长度相当的气泡的生长增加了电导率。细胞的进一步生长（> 30％）导致电导率逐渐降低。该模型可用于导电泡沫的设计和优化。细胞的进一步生长（> 30％）导致电导率逐渐降低。该模型可用于导电泡沫的设计和优化。细胞的进一步生长（> 30％）导致电导率逐渐降低。该模型可用于导电泡沫的设计和优化。