Evolution of nanocrystal size distribution in porous silicon nanoparticles during storage in aqueous media: X-ray diffraction analysis

X-ray diffraction studies of electrochemically prepared mesoporous and microporous silicon particles were carried out to monitor their dissolution in aqueous media. The dissolution process was found to result in either decreasing or an increasing of the mean size of silicon nanocrystallites in mesoporous and microporous samples, respectively. The evolution of nanocrystallite size was related by polydispersity of the initial size distribution and it was described by using a model of “shrinking spheres.” The proposed approach was used to confirm an effect of biopolymer surrounding of silicon nanocrystallites on their stability in aqueous medium. The obtained results and developed model can be useful for potential biomedical applications of porous silicon.