Mapping the influence of solubility and spinnability of alginate in a ternary solvent system

This study presents a scalable strategy for designing the morphology of polysaccharides for applications in food, biomedical fields, and additive manufacturing. An adjustable ternary supramolecular formulation framework consisting of ethanol, glycerol, and water, designed to steer pure sodium alginate (SA) electrohydrodynamic (EHD) forming of fine structures ranging from discrete beads to continuous microribbons is uncovered. The engineered formulation provides enhanced control over solvent composition and solution parameters, including ternary solvent content, and establishes a ternary processing window of 2.0-2.3% w/v alginate, 10-15% v/v ethanol, and 8-12% v/v glycerol, with a zero-shear viscosity (η₀) ranging from 1.2 to 3.0 × 10⁴ mPa s. Within this window, pure alginate microribbons with a minimal diameter of 26.5 μm and aspect ratio between 10 and 20 were achieved. The length and aspect ratio of the microribbons are governed by the alginate concentration, as well as the water and ethanol contents, suggesting opportunities for future research into customized structural optimization tailored to specific target applications. Furthermore, precise control over the synthesis process and solution ratio optimization for pure alginate demonstrates the feasibility of alginate EHD forming, yielding micrometer-scale core-sheath architectures with promising potential for environmentally friendly, sustainable, and pollution-free applications.