Origin of Dynamic Network Formation of 2D Nanofillers in a Flexible Matrix

The aggregation of carbon nanofillers within polymer matrices is a crucial phenomenon for the formation of conducting channels in electrically conductive composites. Herein, a systematic comparison of the effect of 1D and 2D carbon nanofillers, exploiting their dimension‐dependent aggregation in matrices, is performed. The role of flexible matrix in fractal formation is also highlighted by demonstrating that the presence of polar moieties in a polymer matrix affects the agglomeration geometries of functional carbon nanomaterials. Carboxylic acid derivatives of nanotubes and hydroxylated graphene are incorporated into both “functionally rich” polyurethane and apolar polydimethylsiloxane matrices to explore filler–filler and matrix–filler interactions. The in situ ultra‐small‐angle X‐ray scattering analysis performed with simultaneous conductivity measurements, and stretching of flexible film has established a distinct role for loading fraction of functional nanofillers in deciding the stability of conduction networks. The effect of topological differences in composites is observed to be most striking in the case of sheets, where it is shown that the 2D flakes can bend and unfold upon stress, exclusively affecting the percolation and conductive mechanism in composites. These findings help to select the suitable materials to design the next generation of flexible and wearable electronic devices, offering versatility and adaptability in applications.