Ultra-smooth and highly-spherical gold nanoparticles can form uniform colloidal film from evaporating sessile droplets on substrates at relatively high temperature, in which gold nanospheres are assembled at the air-liquid interface due to fast evapor...
Ultra-smooth and highly-spherical gold nanoparticles can form uniform colloidal film from evaporating sessile droplets on substrates at relatively high temperature, in which gold nanospheres are assembled at the air-liquid interface due to fast evaporation and further form multilayers on polystyrene-coated silicon wafer. Then, gold nanospheres at bottom layer are wetted by polystyrene upon thermal annealing around <TEX>$80^{\circ}C$</TEX> and securely trapped in polymer solid film during cooling step. Finally, additionally stacked nanospheres in multilayer film are washed out by simple sonication leaving high-quality colloidal monolayers of gold nanospheres.