POLY(N-ISOPROPYL ACRYLAMIDE) MICROGEL DOPED WITH LUMINESCENT PBS QUANTUM DOTS

Thiol-stabilized PbS quantum dots (QDs) with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol (TGL/DTG) were colloidally prepared at room temperature. Room temperature photoluminescence quantum efficiency of freshly prepared PbS QDs (7%-11%) remained higher than 5% upon aging for three weeks when the nanocrystals (NCs) were stored in an ice-bath in the dark, and higher than 5% for at least five weeks when extra DTG ligands were introduced into the nanocrystal solution followed by stirring every two weeks. Poly(N-isopropyl acrylamide) (PNIPAM) microgels were produced via precipitation polymerization with dimensions of ca. 230 nm and polydispersity of 3-5%. Incorporation of PbS QDs into PNIPAM microgels indicated that PbS can be incorporated into the interior of microgel particles and not at the microgel interface. The combination of reasonable room temperature quantum efficiency and strong, efficient luminescence covering the 1.3-1.55 μm telecommunication window makes these nanoparticles promising materials in optical devices and telecommunications.