The Polymer Society of Korea

Abstract

Thermoresponsive Ag@PLLA/PNIPAm core–shell nanofiber membranes were developed as smart catalytic filters for 4-nitrophenol (4-NP) reduction. The membranes were fabricated by coaxial electrospinning followed by a dual step in situ post growth process, in which Ag seeds in the PLLA shell are converted into uniformly distributed Ag nanoparticles (AgNPs) via UV assisted photoreduction. This embedded strategy overcomes the poor adhesion, heterogeneous loading, and catalyst loss typical of ex situ immobilization of AgNPs, ensuring robust nanoparticle–polymer integration and structural stability. The PNIPAm core, with an LCST near 32 °C, enables thermal modulation of pore structure and local reactant access, providing heat controlled switching of catalytic activity. In this study, the membranes show high conversion and yield while remaining recyclable with minimal aggregation of AgNPs or leaching, demonstrating an efficient, sustainable catalytic filtration platform.