Stable Cellulose Nanofibril Microcapsules from Pickering Emulsion Templates

Electrostatic attractions are essential in any complex formation between the nanofibrils of the opposite charge for a specific application, such as microcapsule production. Here, we used cationized cellulose nanofibril (CCNF)-stabilized Pickering emulsions (PEs) as templates, and the electrostatic interactions were induced by adding oxidized cellulose nanofibrils (OCNFs) at the oil-water interface to form microcapsules (MCs). The oppositely charged cellulose nanofibrils enhanced the solidity of interfaces, allowing the encapsulation of Nile red (NR) in sunflower oil droplets. Microcapsules exhibited a low and controlled release of NR at room temperature. Furthermore, membrane emulsification was employed to scale up the preparation of microcapsules with sunflower oil (SFO) encapsulated by CCNF/OCNF complex networks.