Constructing multifunctional Janus carbon-mesoporous silica particles as Pickering emulsifier for biphasic reaction

Abstract

Janus structure can stabilize oil/water interface and improve interfacial mass transfer in biphasic systems due to its asymmetric wettability and multifunctionality of its dual compartment structure. However, the fabrication of novel Janus structures with resistance to complex application environments is still a challenge due to the difficulty in finding suitable and durable building blocks and connecting them into Janus structures with asymmetric wettability. Herein, Janus carbon-mesoporous silica particles (CMS), featuring a joint of spherical carbon and cubic periodic mesoporous organosilica (PMO), have been fabricated via a facile anisotropic growth. The spacial isolation of hydrophobic carbon domain and hydrophilic PMO domain endows the particle with asymmetric wettability to stabilize emulsion with large droplet size (up to 1.5 mm). The Pickering emulsions emulsified by CMS exhibit high interfacial, thermal and salt stability. Besides, by loading phosphotungstic acid on PMO part, the CMS exhibit a yield of 94% of cinnamaldehyde glycol acetal in biphasic reaction. Furthermore，the CMS have great potential of being a versatile platform not only for catalytic reactions but also for interfacial oriented energy storage, battery, sensing, and biomedical imaging.