Controllable protocols towards nanoparticle self-assembly are important for applications of functional nanomaterials. Evaporation is a simple yet effective method to realize a gold nanoparticle ordered selfassembly, but until now, little attention has been paid to viewing the corresponding assembly process. Herein, with the help of dark-field microscopy, we in situ monitored the whole dynamic process of gold nanorod (GNR) assembly as the solvent evaporated. Differently from the previous coffee-ring effect, rod-shaped hydrophilic GNRs, within certain concentrations, spontaneously assembled into a multiplering pattern on a hydrophobic substrate via droplet drying. The self-assembly mechanism is consistent with a diffusion-driven kinetics, and the influencing factors, including the GNR surface modification, the colloid concentration, the surface property of the substrate, and the shape of the nanoparticles, were systematically investigated.
1.Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China 2.NW Univ Xian, Sch Phys, State Key Lab Incubat Base Photoelect Technol & F, Xian 710069, Peoples R China 3.Chinese Acad Sci, Beijing Natl Lab Mol Sci, Inst Chem, Key Lab Analyt Chem Living Biosyst, Beijing 10090, Peoples R China 4.Tsinghua Univ, Dept Chem, Beijing 100084, Peoples R China 5.ESPCI Paris Tech, PMMH, 10 Rue Vauquelin, F-75231 Paris 05, France