Bacterial cellulose nanofibrils-armored Pickering emulsions with limited influx of metal ions.

This study introduces a hydrophobically modified bacterial cellulose nanofibrils (BCNF)-stabilized Pickering emulsion system, which can limit the influx of metal ions through the interface. We showed that the C18 alkyl chain-grafted BCNF (BCNF) can readily associate to generate a resilient thin membrane at the oil-water interface regardless of the type of oil, which is essential for the production of stable emulsion drops. The viscoelasticity of BCNF-armored Pickering emulsion was feasibly tunable by manipulating the grafting amount of the C18 alkyl chains, as well as controlling the BCNF concentration. We also demonstrated that the BCNF membrane formed at the interface effectively entrapped metal ions through electrostatic binding with the carboxyl groups on BCNF, thus maintaining original UV-absorbing capability of chemical UV filter-containing emulsions. We expect that the BCNF surfactant fabricated in this study has immense potential for the development of various complex emulsion products.