I think i can give little supports to you. there are several synthesis methods are available to produce nanoparticles. Before 1950s people are believing and working with bulk materials like large sized particles. After 1950's richards talk, people come to know that particle with smaller size can give and show excellent properties than bulk or large sized materials. After that researchers try to make smaller particles in various methods. initially all are trying to get smaller particles from the large sized materials like ball milling, grinding and recently thermal evaporation, laser evaporation, sputtering, etc. these methods are called top down approaches to synthesizing nanoparticles also they are physical methods.
But we can also synthesis another one way is through chemical methods and that is called bottom up. to manipulate, control the nucleation and growth by varying the reaction parameters as precursor concentrations, temperature, pressure. this is another way to produce nanoparticles like chemical precipitaion, sol-gel, hydrothermal etc.
Hope u can get some ideas...thank u..