Asymmetric ultrathin silica nanonets as a super-performance emulsifier.

Hypothesis: Pickering emulsions have been used in many fields such as catalytic synthesis, pharmaceutics and oilfield chemicals. They usually have good stability, but in some extreme conditions such as at high temperatures or in special liquid-liquid systems, poor stability is often encountered.

Experiments: Herein, ultrathin silica nanosheets with controllable morphologies were synthesized via a simple interfacial anisotropic self-assembly approach integrated with pore-forming techniques. By regulating the size, density and pattern of the apertures, three types of unique nanosheets including mesoporous nanosheets, meso/macroporous topology-nanosheets and asymmetric nanonets with hollows were obtained.

Findings: After a simple hydrophobic modification, the nanonets exhibited super-performance as particulate emulsifiers, owing to their two-dimensional (2D) structures of large pore volume and hierarchical pore/hollow arrangements. As a result, those silica nanonets can stabilize various emulsion systems at considerably high temperatures that are difficult to be stabilized by conventional particulate emulsifiers even at a dose of 100x higher. This work paves a promising way to develop novel 2D asymmetric nanomaterials with tunable compositions, aperture parameters and morphologies for emulsification and potential applications.