Predicting a Novel Electromechanical Response in Furan-Derived Nanothreads Under Constraints

Furan-derived nanothreads are formed through pressure-induced polymerization of molecular furan at room temperature, with an onset pressure of approximately 10 GPa. Furan-derived syn nanothreads, featuring oxygen atoms arranged along one side of the backbone, offer unique opportunities for electromechanical responses due to the precursor’s polarity and the nanothread’s rigid ladder-like structure. In simulations of densely packed furan-derived syn nanothread crystals without constraints, the crystals can be poled in a rotational external field, resulting in significant dimensional changes in the inter-thread directions while maintaining a constant axial length, with no history of previous rotations. However, when pre-formed cross-linkers, such as dimerized furan precursors (difurfuryl ether), are introduced between threads within the precursor molecular crystal, the cross-linked polar nanothreads retain a memory of their rotations in the electric field, leading to marked shrinkage in the axial direction until saturation is reached. These cross-linked furan syn nanothreads thus form a crystal structure that can be wound up using external electric fields.