(182o) Solution Phase Separation Using Deep Eutectic Solvents for the Fabrication of Chitosan-Based Porous Materials

Chitosan (CTS) is a highly attractive biopolymer for the production of porous materials with potential use as scaffolds for 3D cell cultures, filtration membranes and supporting materials for catalysts or molecular recognizers. Chitosan has versatile properties to be processed into different forms such as films, sponges, hydrogels, nanoparticles, beads and nanofibers. Particularly, the production of chitosan nanofibers is very difficult due to this biopolymer is low spinnable. Chitosan-based porous materials have been produced through lyophilization, where low temperature and vacuum controlled systems are required to eliminate volatile solvents by sublimation; this makes this technique less accessible and expensive. Particle leaching is another common methodology used to this end; micro or nanoparticles are used as porogenic agent, they are mixed with the polymeric solution from which the porous material is to be obtained, then the solvent is removed from the polymer solution and particles are leached from the solid producing this way the final porous material. This methodology involves several steps, and the need to produce or buy the particles used as porogenic agent, as well as the used of leaching solvents that in some cases can be very toxic such as hydrofluoric acid.

This work presents a novel and environmentally friendly methodology for the production of chitosan porous biomaterials, based in the solution phase separation with the use of deep eutectic solvents (DES) as porogenic agent. These solvents stand out as biodegradable, non-toxic and easy recovery solvents, and are very attractive for obtaining pores with uniform diameters and a homogeneous distribution. Making this methodology quite promising over conventional techniques.