Scalable In-Fiber Manufacture of Functional Composite Particles

Advanced fabrication methods must be developed for magnetic-polymeric particles, which are used in medical diagnostics, drug delivery, separation, and environmental remediation. The development of scalable fabrication processes that enables simultaneously tuning of diameters and compositions of magnetic-polymeric particles remains a major challenge. Here, we proposed the production of high-quality magnetic-composite particles through a universal method based on the in-fiber Plateau-Rayleigh instability of polymeric fibers. This method can simultaneously control the particle diameter, hybrid configuration, and functional properties. The diameter of magnetic-polymeric particles can be reproducibly tuned from ∼20 nm to 1.25 mm, a wide range unachievable by conventional solution methods. The final diameter was controlled by the inner/outer fiber diameter ratio. We further showed that the prepared magnetic-polymeric composite particles can be used for the highly efficient recovery of heavy metals (98.2% for Cd²⁺) and for the precise separation of immune cells (CD4⁺ T cells). Overall, the in-fiber manufacture method can become a universal technology for the scalable preparation of different types of magnetic-polymeric composite particles with diverse functionalities.