Hydrophobically modified silica nanolaces-armored water-in-oil pickering emulsions with enhanced interfacial attachment energy

Hypothesis: Anisotropic particles with a high aspect ratio led to favorable interfacial adhesion, thus enabling Pickering emulsion stabilization. Herein, we hypothesized that pearl necklace-shaped colloid particles would play a key role in stabilizing water-in-silicone oil (W/S) emulsions by taking advantage of their enhanced interfacial attachment energy. Experiments: We fabricated hydrophobically modified silica nanolaces (SiNLs) by depositing silica onto bacterial cellulose nanofibril templates and subsequently grafting alkyl chains with tuned amounts and chain lengths onto the nanograins comprising the SiNLs. Findings: The SiNLs, of which nanograin has the same dimension and surface chemistry as the silica nano -spheres (SiNSs), showed more favorable wettability than SiNSs at the W/S interface, which was supported by the approximately 50 times higher attachment energy theoretically calculated using the hit-and-miss Monte Carlo method. The SiNLs with longer alkyl chains from C6 to C18 more effectively assembled at the W/S interface to produce a fibrillary interfacial membrane with a 10 times higher interfacial modulus, preventing water droplets from coalescing and improving the sedimentation stability and bulk viscoelasticity. These results demonstrate that the SiNLs acted as a promising colloidal surfactant for W/S Pickering emulsion stabilization, thereby allowing the exploration of diverse pharmaceutical and cos-metic formulations. (c) 2023 Elsevier Inc. All rights reserved.

Automated summary

The hypothesis of this study is that anisotropic particles with a high aspect ratio can lead to favorable interfacial adhesion and enable Pickering emulsion stabilization. The experiments involved fabricating hydrophobically modified silica nanolaces and studying their behavior at the water-in-silicone oil interface. The findings showed that the nanolaces demonstrated enhanced interfacial attachment energy and improved stability and viscoelasticity of the emulsion.