Design Rules for Mesoporous Silica toward the Nanosize: A Systematic Study.

Mesoporous silica nanoparticles (MSNs) are one of the most frequently employed inorganic materials for catalysis and nanomedicine applications. Nonetheless, a complete control of MSN synthesis parameters aimed at standardizing particle properties is still far from complete, being one of the reasons underlying heterogeneity in their chemical-physical properties, as well as in their biological outcomes. Here, transmission electron microscopy, X-ray diffraction, and volumetric analysis, together with dynamic light scattering and ζ-potential measurements, were combined to carefully characterize different MSNs through a systematic investigation of the role and effectiveness of different factors, such as reaction temperature, time, and pH, on the resulting particle size, texture, and dispersion properties. This methodological approach allowed the implementation of design rules for size-, shape-, and structure-controlled MSNs in the range between 170 and 50 nm.