Synthesis of nanocomposite materials with controlled structures and optical emissions: application of various...

CdSe quantum dots (QDs) were incorporated in polymer films via in situ polymerization using one of the four different monomers having a varied hydrocarbon side chain length, namely, hexyl, lauryl, stearyl, or behenyl methacrylate. This technique resulted in the preparation of a series of the QD-based nanocomposite materials for which laser scanned confocal microscopy imaging revealed a uniform dispersion of nanoparticles within the polymethacrylate matrices. Importantly, the polymer encapsulation of highly luminescent CdSe QDs did not affect their optical properties. The films exhibit the size-quantized optical effects characteristic of QDs. The changes in photoluminescence (PL) intensity of CdSe QDs were investigated as a function of illumination duration in different chemical environments, including the above polymeric matrices and a chloroform solution. Enhancement of the photoluminescence quantum yield for photoactivated QDs in methacrylate polymers was observed. This study of quantum yields of QD-based composites is important for understanding the involvement of surface states of photoactivated QDs as well for identifying ideal polymeric hosts for photoinduced surface passivation.