A Universal Strategy to Increase the Mechanical Performance of Polymer‐Inorganic Composites by Sub‐1 nm Hetero‐Nanowires

Abstract Sub‐1 nm nanowires (SNWs) with diameter near that of a single polymer chain can perform polymer‐like properties, which provides better compatibility for the combination of SNWs with polymers to further improve their mechanical performances. Here, the Ce 2 O 3 ‐phosphomolybdic acid SNWs (CS) are synthesized with flexible and viscous properties. Based on the special polymer‐like properties, a universal method is developed to fabricate polymer‐inorganic composite films by simply mixing CS with various kinds of polymers (including polyimide (PI), polyvinylpyrrolidone (PVP), polyoxyethylene (PEO) and polystyrene (PS)), respectively. The tensile strength and elongation of these films are significantly improved simultaneously while their optical properties remain unchanged. The tensile strength increases by 136% (CS‐PI film), 280% (CS‐PVP film), 256% (CS‐PEO film), 128% (CS‐PS film) compared with pure polymer films, and the elongation can reach up to 55 ± 5% (CS‐PI film), 9 ± 2% (CS‐PVP film), 215 ± 5% (CS‐PEO film) and 17 ± 2% (CS‐PS film), respectively. Meanwhile, the CS can further functionalize the final composites due to their designable inorganic components, and as a demonstration the CS‐PI film is used as a separator in Zn||Zn symmetric cells, which can last for 430 h, almost three times longer than that of commercial glass fiber.