Micromechanical Modeling of Electrical Conductivity and Percolation in CNT /Polymer Nanocomposites by Considering Morphology: Homogeneous, Agglomerated, and Segregated Structures

ABSTRACT The morphology of nanocomposite structures is a key factor influencing the electrical properties of carbon nanotube (CNT)/polymer nanocomposites. During the production, the length and curvature of CNTs often lead to agglomeration, which diminishes electrical properties and increases the percolation threshold by approximately 4 vol.%. However, recent manufacturing advancements have created segregated structures, which significantly enhance electrical properties and achieve percolation thresholds below 0.01 vol.%. This paper presents a micromechanical model using mean‐field theory to predict the effects of agglomeration and segregation on electrical conductivity and percolation in CNT/polymer nanocomposites. The model considers a homogeneous structure ideal and incorporates agglomerated and segregated states based on a novel mathematical approach. The volume of agglomeration and segregation inclusions changes with the amount of CNT fillers, affecting CNT concentration in both inclusions and the matrix. To validate the model, extensive experimental data from various studies on homogeneous, agglomerated, and segregated structures were used. The study reveals a clear correlation between the percolation threshold and the aspect ratio (M), defined by , where is greater than 0.5 for agglomerated states, 0.5 for homogeneous states, and below 0.5 for segregated states. This research provides valuable insights for developing electrically conductive polymer nanocomposites with tailored properties.