Size Separation of Gold Nanorods at the Periphery of Coffee-Stain Ring

摘要

Droplet drying techniques showed in many studies that nanoparticles generally self-assembles in a coffee-stain ring after complete evaporation of the solvent. Suspension comprise of various shapes and sizes in suspension dried on SiO2 substrate at room temperature leaves behind a coffee- stain like ring. High resolution scanning electron microscope (HRSEM) images for at various locations of the coffee-stain ring display some interesting self-assembling behaviour of various shapes of the gold nanostructures. At outer-edges of the deposited ring, side-by-side assembly of nanorods showed that such assembly begins with a thin nanorod and ends with thick ones. In case of thick-thin rods and spheres with relatively dense concentration allows merely thick rods ensemble while other observed in disorder everywhere within the ring. Theoretical nano- interactions also affirms experimental results.