Supported and stable inorganic crystals in nanometric size, such as PbS or other quantum dots, are very desired materials in the form of thin films for the application in technological areas. Herein, an approach to the growth of PbS crystals in poly(acrylic acid) (PAA) ultrathin film covalently immobilized in the polyethylene (PE) surface is described. The method used allows the obtaining of materials with different shapes and sizes by the adjustment of experimental variables. The more homogenous composites with the smallest particles were obtained at pH 6 due to the slower removal of Pb2+ ions from PAA ultrathin film. Hence, the PbS is formed in situ inside of PAA. A direct relationship between Pb2+ and thioacetamide (TAA) concentrations was observed by the analysis of the composite morphologies. More homogenous composites with the smallest particles were obtained in the lowest Pb2+ condition and the highest TAA concentration condition or in the intermediate Pb2+ condition and the lowest TAA concentration condition.
polyethylene ultrathin polymer layers; PbS quantum dots; PbS nanoparticles
