Scalable Industrial Production of Bio‐Based Lignin‐Activated Room Temperature Phosphorescent Fibers

ABSTRACT Room temperature phosphorescence (RTP) fibers derived from natural sources exhibit great potential, but their large‐scale preparation remains challenging. This work overcomes this major bottleneck by demonstrating the first successful large‐scale manufacturing of bio‐based, room temperature phosphorescent (RTP) fibers. By integrating lignin, an abundant biopolymer, directly into a commercial viscose fiber production line, we have developed a cost‐effective process to produce high‐performance phosphorescent viscose (PV) fibers at an industrial scale. The process employed key industrial parameters, including a coagulation bath temperature of 49°C, and a lignin incorporation rate of 1% (w/w) relative to cellulose, with continuous filament collection. These monolithic fibers exhibit a robust and long‐lived green afterglow (lifetime of 217.5 ms) and exceptional mechanical strength (629.2 MPa), properties imparted by the unique Cellulose II matrix formed during the industrial co‐regeneration process. Moreover, the wavelength of PV‐fiber is tunable, ranging from 500 to 520 nm, by changing the excitation wavelength and using an energy transfer strategy. To prove their immediate viability, the PV‐fibers are seamlessly processed into yarns and textiles using standard machinery, creating advanced multi‐level anti‐counterfeiting embroidery and luminescent surgical sutures. This breakthrough provides a direct and tangible pathway from renewable biomass to the mass production of advanced luminescent fabrics, paving the way for their integration into consumer and biomedical products.