A facile synthesis of monodispersed mesoporous silica nanospheres with Pm3n structure

Mesoporous silica nanoparticles (MSNs) have attracted increasing attention for their potential biomedical and catalytic applications. This study reported a facile synthesis of monodispersed mesoporous silica nanospheres (<100 nm) with highly ordered 3D porous structure (Pm3n symmetry) at room temperature by using dodecyltrimethylammonium bromide (C₁₂TMAB) as template and carboxymethyl cellulose (CMC) as dispersing agent via a rapid two-step pH-modulated method. The silica nanospheres were characterized by XRD, SEM, TEM, dynamic light scattering (DLS), N₂ physisorption and ¹³C MAS-NMR spectroscopy. The monodispersed mesoporous silica nanospheres possessed high specific surface area and large pore volume (>1 cm³ g^-1). The presence of CMC increased the solution viscosity and retarded the silica growth rate, thus led to small particle diameter and narrow particle size distribution.