Enhancing silica surface deprotonation by using magnetic nanoparticles as heating agents

In this work, we investigate the possibility of using magnetic nanoparticles embedded into the silica to locally heat up the silica-water interface where the increase in temperature of nanoparticles is induced by an external radio-frequency magnetic field. Through the use of the theoretical model, it is shown that such the process leads to an increase in the total negative charge of the silica surface due to the deprotonation of silanol groups. It is also shown that the efficiency of such an electric charging process depends on the size of nanoparticles. Moreover, the optimal size of nanoparticles allowing for a maximum charging efficiency is determined. This observation may prove to be very important from the point of view of potential applications as it may allow to fine-tune chemical reactions on the silica surface. Some aspects of this work related to the magnetically heated nanoparticles were verified by the experiment.