Effect of magnetic and silica ratio on the synthesis of magnetic mesoporous silica particles

Mesoporous magnetic silica (MMS) particle can be developed as a material for theragnostic-agent. It can offer therapeutic ability through hyperthermia treatment and drug-carrying possibility, while the magnetic particle can also be expected as an MRI contrast agent for diagnostic purposes. An effective MMS theragnostic agent should have high magnetic moment, small size and high surface area. In this work, MMS was synthesized with a variation of the magnetic and silica ratio. The magnetic nanoparticle was synthesized first through the co-precipitation method. The synthesize of MMS was conducted with two variations of magnetic and silica ratio (MMS 1:1 and 2:1) and the porous system was formed during hydrolysis of CTAB at the controlled sintering process. The samples were characterized using FTIR, XRD, VSM, PSA, and nitrogen adsorption-desorption. The MMS 2:1 result shows a larger particle size (more than 300 nm), lower magnetic moment (25 emu/g) compared to the MMS 1:1 (less than 300 nm in particle size and 35 emu/g for the magnetic moment). The nitrogen adsorption-desorption isotherm profiles confirm the formation of a mesoporous structure with nearly the same pore diameter for the two samples but a higher surface area for MMS 1:1. Further analysis should be done to confirm the magnetic nanoparticle position the formation of the mesoporous structure of the materials.