Hierarchical WPU/TiO2 Interfaces Enable Acoustic and Photocatalytic Antibacterial Performance in Recycled Hollow Polyester Felts

Abstract

Abstract Noise pollution and surface contamination impose increasingly stringent requirements on the structural stability and functional integration of sound-absorbing materials. Here, recycled hollow polyester fibers (HPETFs) and low-melting-point polyester fibers (LPETFs) were hot-pressed into porous fiber felts (HPFs). A flexible waterborne polyurethane (WPU) coating was then introduced to immobilize TiO2 nanoparticles, producing multifunctional HUT fiber felts. WPU formed fiber coatings and node-bridging structures while preserving hollow fibers and interconnected pores, thereby enhancing interfacial damping and structural stability. The noise reduction coefficient (NRC) of HPF/WPU-12 increased from 0.193 for HPF to 0.258, a 33.7% improvement. HPF/WPU-12 also retained approximately 98% shape recovery after 1000 compression cycles. TiO2 was concentrated at and near the felt surface while retaining its anatase phase. At a thickness of 1.97 cm, HUT-10 achieved an NRC of 0.36. Under ultraviolet irradiation, HUT-10 degraded 64.8% of methylene blue within 7 h. Its maximum inhibition rates against Escherichia coli and Staphylococcus aureus were 93.3% and 94.6%, respectively. The synergy among multiscale pore dissipation, WPU viscoelastic damping, and TiO2 photocatalysis integrated sound absorption, self-cleaning, and antibacterial functions. This strategy offers a route to multifunctional sound-absorbing materials based on recycled polyester.

The authors' abstract, as published at the source. ACS Applied Polymer Materials, 2026 · DOI ↗