A huge amount of waste textile is produced every year, and the majority is either burned, or buried in landfills, or downcycled. We propose making high added-value materials, aerogels, from textile waste, using ionic liquids. Aerogels are light-weight and nanostructured porous materials with high specific surface area. Depending on the type of textile, we use ionic liquid either to completely dissolve it (case of rayon or viscose), or to selectively dissolve cellulose (case of polycotton). Cellulose aerogels were made in the form of beads by prilling via dissolution in ionic liquid, coagulation and drying with supercritical CO₂. Reference cellulose aerogel beads were made from microcrystalline cellulose to compare with textile-based aerogels.

The rheological properties of cellulose-ionic liquid solutions were studied to select the processing conditions. Aerogel beads of the size from 0.5 to 1.5 mm with excellent circularity were obtained. Cellulose-based aerogel beads from textile and from microcrystalline cellulose have density around 0.1 g/cm³, porosity around 90% and high specific surface area, around 300 m²/g. Cytotoxicity tests showed that these aerogels may potentially be used for life science applications.

Acknowledgements

We are grateful to Institut Carnot MINES for the financial support of this work, Julien Jaxel (PERSEE) for the drying with supercritical CO₂, Antoine Perron (GALA – RAPSODEE) for the prilling and Suzanne Jacomet (CEMEF) for the help in SEM pictures.