Preparation of nanomaterials

Many methods exist for the synthesis of fine particles or nanoparticles. The main two methods involved here are top down and bottom up approach.

One example for top down approach is high energy ball milling. Take a microparticle and put in vials of a high energy ball milling uint. Moderate rpm will lead fine particles and high rpm will result in very fine particles. But risk of dissociation into constituent particles exists in high rpm milling. We can use stainless steel, tungsten carbide and agate vials and balls.

Chemical coprecipitation is a classic example for bottom up approach. Here salt solutions are taken as starting precursors. Particle size tuning is easily possible here by the variation of temperature and pH.