A Study On Arrangement Of Silica Nanoparticles On Si Substrates Of Different Wettability In Droplets With Or Without Ethylene Glycol

Because nanoparticles are widely used in several areas such as biosensors, optical devices, displays, and nanofluidic devices, several studies have been conducted to prevent nonuniform deposition of nanoparticles. Recent studies have shown that the coffee-ring effect is a major reason for the nonuniform arrangement of particles during the evaporation of colloidal droplets. The coffee-ring effect may be restrained by changing the viscosity of liquid or behavior of droplets during evaporation. In this study, ethylene glycol was added to the colloidal solution to change the viscosity, and the wettability of the substrate was also modified to change the behavior of the droplet. Experiments have shown that the coffee-ring effect was restrained such that a uniform arrangement of nanoparticles could be obtained by the aforementioned methods.