Tunable Crosslinked Polyvinyl Alcohol/Polyethylene Glycol (cPVA/PEG) Nanofiber Membranes with Enhanced Mechanical and Hydrophilic Balance

In recent years, membrane separation technology has undergone continuous advancements. Microfiltration (MF) membranes, as an important type, are usually prepared by electrospinning—a simple and efficient method. This study reports the development of crosslinked polyvinyl alcohol/polyethylene glycol (cPVA/PEG) nanofiber membranes through a combination of electrospinning and chemical crosslinking, investigating the effects of different crosslinking concentrations on the membrane morphology, surface wettability, and tensile properties. Comprehensive characterization was carried out by using scanning electron microscopy (SEM), a Fourier-transform infrared spectrometer (FTIR), an X-ray diffractometer (XRD), a thermogravimetric (TG) analyzer, differential scanning calorimetry (DSC), a contact angle tester, a universal testing machine, etc. The results showed that at the crosslinking concentration of 15%, the cPVA/PEG fiber membrane achieved a breaking stress of 29.07 ± 2.60 MPa, a breaking strain of 77.60 ± 6.02%, and a porosity exceeding 43%. SEM, FTIR, XRD, TG, and DSC analyses collectively confirmed the occurrence of chemical crosslinking within the membrane structure. The cPVA/PEG-15 membrane exhibited no observable shrinkage or curling upon water contact, combined with excellent hydrophilicity and lipophilicity in the air. These properties indicate that the membrane can serve as a novel functional membrane substrate (e.g., as hydrophilic separation layers) and is expected to play an important role in fields such as seawater desalination and wastewater treatment, demonstrating significant application potential.