Sonochemical synthesis of lead hydroxy bromide needles

A sonochemical approach to the preparation of elongated needles of Pb(OH)Br using a cationic surfactant, cetyltrimethylammonium bromide (CTAB) is reported. A shape transition of the particles is found to occur due to the presence of an organized medium consisting of a cylindrical, interconnected network of thread-like micelles. Transmission electron micrographs (TEM) show the presence of elongated Pb(OH)Br particles. The needles have been characterized by powder XRD, IR, TGA and DSC. The needles have also been found to decompose in the electron beam during TEM measurements, the decomposition product being one of the polymorphic forms of PbO·PbBr2.