Magnetically Separable Conjugated Microporous Triphenylphosphine Networks Enabling Dual-Gated Photoinduced Atom Transfer Radical Polymerization

Abstract

Magnetic stimulation demonstrates exceptional advantages in control precision, penetrability, stability, and biocompatibility, surpassing other stimulus modalities, which positions it as an ideal candidate for remote, noncontact, long-duration, and multifunctional applications. By implementing strategic molecular engineering approaches, advanced photocatalytic platforms responsive to a variety of external stimuli, beyond just light, can be developed. In this study, we report the design of a magnetism/light dual-gated photoinduced atom transfer radical polymerization (photo-ATRP) system using Fe₃O₄@PP-E core–shell nanocomposites. The nanocomposites were fabricated by incorporating triphenylphosphine as the photocatalytic component and 2,4,6-tris(4-ethynylphenyl)-1,3,5-triazine as the linker via a Sonogashira–Hagihara cross-coupling reaction on magnetite (Fe₃O₄) colloidal nanocrystal clusters. This study included the optimization of polymerization conditions to control molecular weights and achieve fast reaction kinetics while also demonstrating the recyclability of the photocatalyst through magnetic attraction. Moreover, dual-gated photo-ATRP was demonstrated by switching the light on/off and applying the magnet in/out. This system was also applied to synthesize well-defined protein–polymer conjugates under biologically relevant conditions, preserving their biological activity. This approach contributes to advancements in polymer manufacturing by enhancing catalyst removal processes and promoting sustainability.