A comprehensive study on the comparison between casted films and electrospun nanofibers of poly (vinyl alcohol)/chitosan blends: wettability, thermal, antioxidant, and adsorbent properties.

This study presents the preparation of functional poly (vinyl alcohol) (PVA)-chitosan (CS) blend materials at different ratios (PVA:CS (w:w) = 95:5, 90:10) using electrospinning and solution casting, and systematically compares their properties. The fabricated samples were evaluated in terms of morphological structure, water wettability, thermal behavior, antioxidant capacity, and adsorbent properties for the removal of methyl violet (MV) from aqueous solutions. The presence of PVA and CS in the prepared samples was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). The scanning electron microscopy (SEM) images showed that the electrospun fibers exhibited a cylindrical, smooth, bead-free, and homogeneous morphology with average diameters ranging from 180 ± 20 to 230 ± 30 nm. Increasing of CS content led to enhanced hydrophobicity and improved thermal characteristics in both electrospun fibers and casted films. Furthermore, the electrospun mats demonstrated lower wettability, but higher thermal stability and transition temperatures compared to casted films. Moreover, incorporation of CS into PVA significantly enhanced antioxidant activity against DPPH and ABTS, with electrospun nanofibers demonstrating greater antioxidant activity than casted films. Additionally, the electrospun materials with increased higher CS content exhibited enhanced adsorption capabilities. Higher CS concentrations increased the number of functional groups, thereby facilitating greater interaction with dye molecules and improving adsorption. Specific interactions between PVA and CS functional groups played a crucial role in determining the properties of the materials, depending on the processing method. In summary, this comparative study of casted films and electrospun nanofibers of PVA-CS blends offers valuable insights into their properties and potential applications in biomedical and environmental fields.