Ultrasmall Sulfur‐Dots‐Mediated Facile Photopolymerization for the Production of Smart Injectable Ink for 3D Printing Applications

Abstract Sulfur dots (S‐dots) eliminate the need of expensive and toxic conventional photocatalysts or transition metal in photoinduced reversible deactivation radical polymerization (photoRDRP). Herein, non‐metallic S‐dots mediated photoRDRP of N,N‐dimethyl acrylamide (DMA) are developed for the first time. This technique allows for the precise synthesis of narrow‐dispersed poly(N,N‐dimethyl acrylamide) (PDMA) and double hydrophilic poly(N, N‐dimethyl acrylamide)‐ block ‐poly(2‐hydroxyethyl acrylamide) (PDMA‐ b ‐PHEAA) diblock copolymer suitable for contaminant removal from water. Also, its subsequent modification into a poly(N,N‐dimethyl acrylamide)‐ block ‐poly(N‐(2‐((4‐vinylbenzyl)oxy)ethyl)acrylamide) (PDMA‐ b ‐PVBEAA) diblock copolymer gives ultra‐fast gelation and production of writable ink‐gel, which is exceptionally well‐suited for 3D printing applications, enabling the creation of precise and defined shapes. This innovative material serves as an intriguing scaffold for tissue engineering and other biomaterial applications, especially in areas that demand rapid and customizable manufacturing solutions.