3D printing of cellulose nanocrystal-based Pickering foams for removing microplastics

Environmentally friendly porous materials have garnered widespread attention for the removal of nondegradable pollutants because of their high specific surface areas. Herein, biosafe ethyl lauroyl arginate hydrochloride (LAE) was incorporated as a Pickering stabilizer to enhance the hydrophobic properties of cellulose nanocrystal (CNC) foam. The obtained LAE-CNC foam exhibited excellent 3D printing characteristics. The effects of different CNC loadings on the morphology, stability, rheology, and 3D printability of the Pickering foams were investigated. While an increase in CNC loading enhanced the apparent viscosity and continuous phase network of the foam, which was beneficial for maintaining the structure after printing, excessive CNC addition may have compromised the continuity of printed lines and interlayer adhesion, deteriorating the printing quality. The foam with 10.0 wt% CNC and 0.15 wt% LAE exhibited balanced stability and porosity, along with optimal printing performance. Subsequently, the foam was printed and freeze-dried to obtain porous scaffolds. An increase in infill spacing resulted in enhanced adsorption of polystyrene microspheres owing to the enlarged surface area. Overall, this highly stable and sustainable LAE-CNC foam is a promising printing ink with potential applications in various fields, including mitigating microplastic pollution.