Identification of Variables and Determination of the Mechanism Affecting the Effective Properties of Representative Volume Elements of Unidirectionally Aligned CNT-Based Nanocomposites

This study identified the governing variables affecting the effective properties of the representative volume element (RVE) of nanocomposites consisting of unidirectionally aligned carbon nanotubes (CNTs) and determined the mechanism through which they act. For this purpose, multi-walled nanotubes (MWNTs) and polyvinylidene fluoride (PVDF) were selected as the components of the nanocomposites, and Monte Carlo simulations were conducted to examine the variability of the effective properties according to the CNT length. The governing variables affecting the effective properties were identified considering the conditions under which the selected CNTs can be arranged inside the RVE. Using the geometrical relationship between the RVE and CNTs, a simplified two-parameter equation that can calculate the effective properties of the RVE was derived. Using this equation and Monte Carlo simulations, this study confirmed that the characteristics of the effective properties vary with changes in the length of the RVE and the length fraction of the CNTs, and the mechanism of these changes was determined. In addition, the variation in the characteristics of the effective properties according to the coefficient of variation of the CNT length was also determined.