One-pot synthesis of amino functionalized mesoporous silica materials: using simulations to understand transitions between different structures

The rich phase behavior of surfactants can be exploited to design materials with a given desired structure and properties. One example includes amino functionalized mesoporous silicas, which can be used in different environmental applications, including removal of heavy metals from water and CO2 separation and purification. These applications may require a high concentration of functional groups, but the increased concentration of hybrid organic-inorganic precursors can lead to the destruction of the liquid crystals or transformation into other phases. In this work, we modeled the phase behavior of such systems using lattice Monte Carlo simulations and analyzed the distribution of hybrid organic inorganic precursors to explain the observed changes in the liquid crystal structures. In particular, we observed that if the hybrid precursor is sufficiently hydrophobic, it can act as a cosurfactant, swell the core of the surfactant liquid crystal, and lead to structures with smaller interfacial curvature. On the other hand, if the hybrid precursor acts as a cosolvent it will solubilize the surfactant leading to the destruction of the preformed liquid crystal.