Preparation of biodegradable nanoporous microspherical aerogel based on alginate

Supercritical extraction of the solvent from organic gels, like polysaccharides, enables the production of highly porous biodegradable aerogel with a high surface area. The structural properties of the produced aerogel depend mainly on the preparation methods and the composition of the gel phase. This work presents a new method to produce biodegradable microspherical alginate aerogels particles using an emulsion technique. Water in oil (W/O) emulsion was produced by mixing a Na–alginate solution (dispersed phase) with oil (continuous phase) followed by cross-linking the dispersed phase to form the gel particles. The gelation parameters as well as the emulsion process parameters were investigated in order to control the form and the structural properties of the produced alginate aerogel. Alginate aerogel microspherical particles with a high surface area up to 680 m2/g and relatively large pore volume up to 4.0 cm3/g and different mean particle diameters ranging from 25 μm to few hundred microns were produced using the presented method.