Recyclable 2D Colloid Surfactants with High Catalytic Activities at Pickering Emulsion Interfaces

Abstract

AbstractThis study introduces a novel 2D colloid surfactant system that exhibits catalytic activity at the interface of a reactant‐containing water‐in‐oil Pickering emulsion microreactor. To this end, amphiphilic nanoplatelets (ANPLs) are fabricated with hydrophobic poly (n‐butyl methacrylate) brushes on one face, and hydrophilic poly (2‐aminoethyl methacrylate) brushes on the other face via surface‐induced activators regenerated by electron transfer atom transfer radical polymerization (SI‐ARGET ATRP) on zirconium hydrogen phosphate (ZrHP) nanoplatelets. Subsequently, in situ reduction of metal precursors on the primary amine reaction sites on the hydrophilic face of ANPLs is conducted, thus enabling the production of ANPL catalysts (ANPLcat): ANPLAg, ANPLPd, and ANPLAu. Owing to the platelet geometry and catalytic functionalization, the ANPLcat demonstrates excellent ability to stabilize the Pickering emulsion reactant drops, while exhibiting its own catalytic activity at the interface. It is demonstrated that this ANPLcat system has a high catalytic activity that requires a short reduction reaction time with the speed of which is 750% higher compared with the spherical colloidal surfactant catalyst. In addition, ANPLcat is easily recoverable and recyclable. These results highlight that the ANPLcat‐based emulsion microreactor system is expected to be widely applied as a high‐performance catalyst for various organic chemical reactions.