Anisotropic Electrical Conductivity in Close-Packed Two-Dimensional Polyaramids
Year: 2026
Type: preprint
Abstract: Polyaramids such as Kevlar ® are renowned for their high mechanical strength and chemical resistance; however, their non-conjugated backbones render them electrically insulating. Orbital alignment can allow close-packed stacked molecules to exhibit long range conduction, opening the possibility that insulating nanomaterials may form conducting arrangements. Herein, we report two-dimensional (2D) polyaramids with tailored end-groups that promote tighter molecular packing as their size decreases. Terminal groups with the size of a single methyl result in aligned films that exhibit highly anisotropic electrical conductivity up to 1.39 × 10 –4 S m –1 , comparable to or exceeding many undoped conjugated polymers. Charge transport occurs orthogonally across aligned, stacked polymer platelets while the in-plane direction remains insulating. The anisotropy reverses the behavior typically observed in-plane conduction of stacked 2D nanomaterials. The resulting films are photoconductive under 405 nm illumination with an external quantum efficiency of 0.62%. The mechanical and chemical stability of such conductive 2D polyaramids enables the first single-component, acid-stable polymer electrodes based on non-conjugated frameworks, capable of operating in harsh environments while exhibiting perfectly invariant cyclic capacitance for over 10,000 cycles at pH 2. The stability is enabled in part by the impermeability of such films to moisture and oxygen, underscored by their ability to suppress perovskite degradation with a 150 nm coating. Together, these findings underscore a newly realized mode of electrical conduction in close-packed 2D polymers, enabling ultra-lightweight and chemically stable electrodes for energy storage and sustainability applications.
Source: ChemRxiv
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223697089