The dispersion of silver nanoparticles with physical dispersal procedures

Dispersion degree strongly influences the rheological properties of nanosized particles containing suspension and, as a consequence, the quality of the deposited film. Furthermore, their applications will be rigorously restricted if the bad dispersion cannot be solved effectively. In this investigation, two physical dispersal processes, mechanical mixing with a three-roller mill and sonication, are used to disperse the nanosized silver particles in ethylene glycol and their effectiveness in dispersion are compared. The particle size distributions after dispersion with various procedures are observed by field emission scanning electron microscope (FE-SEM) and measured by image analysis technique. The measurement results show that mixing with a three-roll mill is an effective tool to break the agglomerates of silver nanoparticles in solvent, resulting in a better dispersion. The dispersion degree effect on the rheological properties and thixotropic characteristics of these suspensions are also elucidated. In addition, the film deposited from suspension with Ag nanoparticles mixed by three-roller mill has the lowest resistivity of approximately 3.64 × 102 μΩ cm.