The synthesis of quantum size lead sulfide particles in surfactant-based complex fluid media

Abstract The relative roles of the ion interactions, molecular complex formation, and the local structure of the medium on the formation of nano-sized particles of lead sulfide (PbS) in a nonionic surfactant/water/oil microemulsion have been investigated. Comparison of the reaction carried out under conditions of minimal hydrolysis of the cation (low pH) in two different counterion/acid systems (nitric or perchlorate) indicates that hydrolysis does not play a significant role in the production of PbS in fine particle form. Furthermore, the nature of the counterion, NO 3 or ClO, 4 , used did not affect the particle formation. Variation in the composition of the microemulsion used (dodecyl tetracthoxyethylene glycol ether/water/hexane) showed little effect on the particle formation. This finding implies that the presence of closed microemulsion droplets is not, per se, important for the precipitation of nano-sized particles in this case. Order of mixing studies implies that interaction of a complexation type is the most important step in the synthesis.