Tailored Silica Macrocellular Foams: Combining Limited Coalescence-Based Pickering Emulsion and Sol-Gel Process

Solid-sate monolithic macrocellular foams are synthesized by mineralizing the continuous phase of oil-in-water Pickering emulsions, used as templates, with the solgel process. For the first time, taking advantage of the limited coalescence phenomenon occurring in emulsions stabilized by solid particles, concentrated emulsions with calibrated drop size are produced, leading to the synthesis of monolithic foams with nearly monodisperse macroscopic voids. Such a strategy allows independent tuning of the macrocellular void diameters from 20 to 800 mu m and the diameter of the windows connecting adjacent cells. The obtained macrocellular foams also bear micro- and mesoporosity, leading to Brunauer, Emmet and Teller (BET) surface area values between 700 and 900 m2 g-1 with a good mesopores monodispersity.