Janus bilayer fibrous membrane of polyethylene oxide-chitosan@cellulose acetate with directional water transport for efficient pork and cherry preservation.

A Janus bilayer fibrous membrane was fabricated via electrospinning combined with layer-by-layer self-assembly technology for the preservation of pork and cherries. This Janus membrane consists of a superhydrophilic layer prepared from polyethylene oxide-chitosan (PEO-CS) and a hydrophobic layer composed of cellulose acetate (CA). PEO and CS are interconnected via intermolecular hydrogen bonds. The asymmetric wettability on both sides of the membrane endows it with "fluid diode" properties, enabling the membrane to spontaneously absorb water from the pork surface. The PEO-CS@CA Janus fibrous membrane possesses a hierarchical pore structure with pore sizes of 2.6 μm and 36.0 μm, where the hydrophilic PEO-CS layer and hydrophobic CA layer are bonded via hydrogen bonds. Specifically, under storage conditions of 4 °C and 75% relative humidity (RH), the PEO-CS@CA membrane was capable of prolonging the shelf life of pork by 4 days and cherries by 6 days.