Sequential self-assembly by controlling interactive forces between microparticles

This paper describes binding-sequence control in self-assembly of microparticle by changing interactive forces from the outside. We demonstrated a sequential self-assembly with two binding steps. At the 1st step, the microparticles start to bind to each other on their hydrophobic surfaces (surface A) in aqueous solution. By changing the pH of the solution, the particles subsequently connect on their hydrophilic surfaces (surface B) at the 2nd step. We confirmed that this sequential process increases the yield of the assembled structure, and concluded that pH control is effective to achieve a sequential self-assembly.