Preparation of silver colloid and enhancement of dispersion stability in organic solvent

Silver colloid of nanometer size was prepared in liquid phase by a reduction method. AgNO3, FeSO4·7H2O, and Na3C6H5O7·2H2O were used as silver precursor, reducing agent and dispersing agent, respectively. As precursor concentration was decreased or the concentration of dispersing agent was increased, the prepared particle size was decreased from 180 nm to 20 nm. Apparently, the particle size seemed to be decreased with the increase of stirring rate, but it was confirmed by TEM that the size of primary particle remained the same. This result indicates that the uniformity of precursor concentration in the reactor affects the particle size and the stirring rate should be kept higher than the critical value to prevent the agglomeration of particles.