Electrospinning and electrospray deposition offer complementary routes for the fabrication of hierarchical membrane structures with controlled morphology across multiple length scales. In this work, biobased polymer membranes intended for water ultrafiltration are fabricated using a combination of electrospun fibrous layers and electrosprayed polymer particle deposition. The approach enables independent tuning of support structure, interlayer architecture, and surface topography while maintaining a fully polymeric and chemically compatible system.

The electrospun layers are produced from biobased polyesters and polyamides, yielding micro- to submicron-scale fibrous mats with high porosity and interconnected pore networks. Subsequent electrospray deposition of polymer solutions generates particulate surface layers with characteristic particle sizes in the submicron to micrometre range, forming a hierarchical surface morphology. The resulting membranes exhibit a distinct multi-scale architecture consisting of a macrofibrous nonwoven support, a fibrous interlayer, and a particulate top layer.

Morphological characterization is performed using scanning electron microscopy to assess fibre diameter distributions, particle size, surface coverage, and layer integration. Surface properties are evaluated by contact angle measurements and surface chemical analysis to assess wettability and functional group availability. The influence of electrospinning and electrospray parameters on layer continuity, surface roughness, and structural uniformity is discussed. The presented results provide insight into the structural design space of biobased electrospun and electrosprayed membranes and establish a foundation for subsequent evaluation of ultrafiltration performance.