Silver carboxylate nanostructure nucleation and growth on AgBr crystals

The initial stage of the reaction between sodium stearate (NaSt) and AgNO₃ produces silver stearate (AgSt) micelles, [(C ₁₈H₃₅O₂)_x(Na_x-y)(Ag _y)(H₂O)_z], and aggregations of these AgSt micelles in the form of cubic pre-AgSt crystals. When cubic grains of 50 nm AgBr are added to the NaSt dispersion prior to the AgNO₃, the reaction proceeds to form the silver stearate micelles, but not the aggregation of those micelles. Instead, the {111} silver ion planes of the cubic AgBr crystal corners provide nucleation sites for silver stearate micelle deposition and crystal growth. After nucleation, the AgSt micelles evolve into nanostructured bud-like formations via an epitaxial interface on one or several corners of each AgBr cubic crystal. Over time, additional AgSt micelle deposition enables the buds to grow longer into strand-like structures, which then connect to form the beginnings of the ultimate silver stearate crystal plates.