The high demand of flexible electronics and the miniaturization of electronic components have been increasing very rapidly. Nanotechnology and in particular nanoparticles have become very important for the development of new technologies and applications which depend on the synthesis and characterization of nanoparticles with specific properties. Significant attention has been focused on the characteristics of the nanoparticles since their properties, particle size and shape are very different when compared to those of the bulk materials. In order to produce nanoparticles with more efficient structures and electronic properties for nano ink, it is necessary to control the particle size to avoid agglomeration. Currently, the nanoparticle size and its agglomeration is controlled by surfactants, but some studies have shown that adding surfactants have negative effects on the conductivity of the nanoparticles along with the high curing temperatures of nano-ink. In this study, silver nanoparticles were synthesized by adding methanol to water instead of surfactants in order to control the silver nanoparticle size. The water and methanol solution was prepared by using different ratios v/v of water/methanol obtaining a liquid–liquid interface and forming a molecular–molecular interface restricting the silver ion movement in the solution. In addition to the liquid–liquid interface, the ion concentration and movement were also restricted through a spraying mist by using ultrasonic waves. The silver ion and the reducing agent were found to have a difference in concentration by the spraying mist method. The movement of the silver ions and the reducing agents were controlled by the difference in concentration. It was observed that the control of the nanoparticles and ion movement was more efficient by spraying silver ion solution than using a reducing agent solution. We confirmed that by increasing the volumetric ratios of methanol the silver nanoparticle size also increased. The mist particle size and the concentration were also calculated at different volumetric ratios of methanol.