Copper-based metal organic framework/polymer foams with long-lasting antibacterial effect

Abstract

The development of durable and effective antibacterial materials has been a research hotspot. Here, we reported a new kind of long-lasting stable antibacterial material [Cu-metal–organic framework (MOF)-embedded polyethylene (PE)/ethylene vinyl acetate copolymer (EVA), namely Cu-MOF-embedded PE/EVA] through extrusion foaming, and its structure was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and energy dispersive spectroscopy (EDS). The degree of agglomeration or cluster formation, thermal stability, and melting point temperature of different contents of Cu-MOF/PE/EVA foams were evaluated by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC), respectively. The results indicated that with the increase of Cu-MOF content, the average size and swelling ratio for foams increased, instead, the density decreased. Besides, the surface gradually showed good hydrophobicity. Remarkably, the water absorption rate was nearly 8 times that of pure PE/EVA when the Cu-MOF content reached 3%. Since Cu-MOF is stably embedded in the foaming structure and well dispersed, it can release Cu²⁺ at a rate of about 37 ppb/day in foams containing 3% Cu-MOF, which not only maintains the antimicrobial capacity up to 99.2%, but also have no cytotoxicity. Finally, a promising new candidate for medical material with excellent, durable antibacterial ability was proposed.

Graphical Abstract