Influence of Spirulina and Chlorella Biomass on the Structure and Transport Properties of Electrospun PVA-Based Nanofiber Mats

Electrospun poly(vinyl alcohol) (PVA) nanofibrous mats containing Spirulina or Chlorella biomass were deposited directly onto a woven cotton fabric to produce fabric–nanomat composites. The effects of the microalgal species on the physicochemical properties of the electrospinning solutions, nanofiber morphology, nanomat development, surface porosity, and through-plane transport properties were comparatively investigated. The incorporation of either biomass increased the viscosity, electrical conductivity, and surface tension of the PVA solution, indicating interactions between the microalgal components and the polymer matrix. FTIR analysis showed that the nanomats largely retained the characteristic absorption bands of neat PVA, with minor spectral features consistent with the incorporated biomass. SEM observations revealed continuous, bead-free nanofibers without visible surface defects. The average fiber diameters were 192 ± 34 nm for PVA/Spirulina and 173 ± 39 nm for PVA/Chlorella. The PVA/Chlorella system produced thicker nanomats, whereas the PVA/Spirulina system exhibited greater projected-area expansion during prolonged electrospinning. Surface porosity was significantly higher for PVA/Spirulina nanomats (57.54 ± 1.34%) than for PVA/Chlorella nanomats (52.69 ± 1.49%). Correspondingly, the PVA/Spirulina composites exhibited higher air permeability, whereas both systems showed comparable relative water vapor permeability. These results demonstrate that the type of microalgal biomass influences nanomat development, morphology, porosity, and air permeability while having a limited effect on relative water vapor permeability, providing a basis for the development of functional textile and filtration-related materials.