Structuring Pickering Emulsion Interfaces with Bilayered\nCoacervates of Cellulose Nanofibers and Hectorite Nanoplatelets

Abstract

In this study, we present a water-in-silicone\noil (W/S) Pickering\nemulsion system stabilized via in situ interfacial coacervation of\nattractive hectorite nanoplatelets (AHNPs) and bacterial cellulose\nnanofibrils (BCNFs). A bilayered coacervate is generated at the W/S\ninterface by employing the controlled electrostatic interaction between\nthe positively charged AHNPs and the negatively charged BCNFs. The\nW/S interface with the bilayered coacervate shows a significant increase\nin the interfacial modulus by 2 orders of magnitude than that with\nthe AHNPs only. In addition, we observe that water droplets are interconnected\nby the BCNF bridging across the continuous phase of silicon, which\nis attributed to the diffusive transport phenomenon. This droplet\ninterconnection results in the effective prevention of drop coalescence,\nwhich is confirmed via emulsion sedimentation kinetics. These results\nindicate that our bilayered coacervation technology has the potential\nof developing a promising Pickering emulsion platform that can be\nused in the pharmaceutical and cosmetic industries.