In the preparation of metal nanoparticle the particle size decrease with increasing capping (PVP) agent up to some value, but the size of the particle increase after adding more capping agent. Why the particle size increase after adding high amount of PVP? thanks
I don’t know your system, but this process depends on media and the PVP solubility threshold. When its concentration becomes higher this value, polymer forms micelle-like agglomerates, and its stabilizing ability falls (the ability to regulate nucleation and nanoparticles growth).PVP solubility decreases when salinity or temperature increases, too. The threshold is lower in non-aqueous solvents (for example, see the formation of silver nanowhiskers in PVP-glycols). Probably, it’s your reason.
If you use iron as a core for your nano particals so the addion of pvp will led to separate the atoms and this will lead to decrease size, if you add more pvp this will led to make dense layer of pvp and this will cause increase size.
