First Macro-Mesocellular Silica SBA-15-Si(HIPE) Monoliths: Conditions for Obtaining Self-Standing Materials

Combining the emulsion and the cooperative templating mechanisms, self-standing macro-mesoporous SBA-15-Si(HIPE) monoliths (90–95% of porosity) have been synthesized for the first time. Materials have been prepared from the Pluronic (P123)/dodecane/water system in the presence of salt and TEOS as silica scaffold precursor. As increasing the ionic strength was shown to be ineffective toward obtaining self-standing monoliths, we induced a kosmotrope “order maker” effect within the starting silica gel making the use of (NH 4 ) 2 SO 4 salt to enhance silica polycondensation. Beyond its effect over the silica polycondensation, we show that the (NH 4 ) 2 SO 4 kosmotrope character has also a strong impact over the micelles organization at the mesoscale, with an input over the voids diameter and connections at the macroscopic length scale. The obtained SBA-15 x Si(HIPE) self-standing foams exhibit thereby highly ordered mesopores, high specific surface area, and tunable open macroporosity while offering mechanical strength (Young’s modulus) of 0.15–1 MPa without collapsing at high strain.