Preparation of spherical nanostructured poly(methacrylic acid)/PbS composites by a microgel template method.

Spherical poly(methacrylic acid)/PbS (PMAA/PbS) composites with a fishnet-like surface and core-shell structure were prepared by a microgel template method. The composites were prepared in two steps. Pb(Ac)(2) was dissolved in MAA solution before it was polymerized into microgels in an inverse suspension system. In this way, Pb(2+) was trapped within the microgel network. Then, H(2)S was introduced slowly into the system, and the metal ions were deposited within the microgels as PbS. The presence of PbS was confirmed by X-ray diffraction (XRD) and thermogravimetric measurements, and the morphology of the composites was characterized by scanning electron microscopy (SEM). It was found that the surface structure of the microparticles depends largely on the nature of the continuous phase of the system. The microparticles from xylene have a fishnet-like surface structure, and the inner structure and composition of the particles are different from the outer structure and composition. The surface of the particles from cyclohexane, however, appears smoother and denser than the surface of the particles from xylene. The different structure of the particle surfaces from the two systems has been attributed to the differences in template structure.