Herein, we report on the synthesis and characterization of a series of mesoporous silica nanoparticle (MSN) materials with various porous structures and particle shapes, such as spheres, ellipsoids, rods, and tubes, by using different RTIL templates, such as 1-tetradecyl-3methylimidazolium bromide (C14MIMBr), 1-hexadecyl-3methylimidazolium bromide (C16MIMBr), 1-octadecyl-3methylimidazolium bromide (C18MIMBr), and 1-tetradecyloxymethyl-3-methylimidazolium chloride (C14OCMIMCl), respectively (Figure 1). To study the mass-transport properties of the CnMIM-MSN materials, we investigated the controlled release profiles of these materials by utilizing the RTIL templates as antibacterial agents against the Gram (-) microbe Escherichia coli K12 as depicted in Figure 2. Our results indicated that the rates of RTIL release from the MSN materials are governed by the particle and pore morphology leading to different antibacterial activities.