Preparation of optically active substituted polyacetylene@CdSe quantum dots composites and their application for low infrared emissivity

Optically active substituted polyacetylene@CdSe quantum dots (SPA@CdSe QDs) nanocomposites were fabricated by grafting helical SPA polymers onto the surface of semiconductor QDs through ester linkage. Optically active SPA polymer derived from chiral amino acids was copolymerized by a rhodium zwitterion catalyst and was evidently proved to adopt a predominately single-handed helical conformation. The SPA@QDs nanocomposites were characterized by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and thermogravimetric analysis. The results indicated that the organic SPA matrix exhibited an enhancement in thermal stability after the hybridization with CdSe QDs, while the blended QDs maintained their original crystalline structure during grafting. The infrared emissivity properties of the SPA@QDs nanocomposites at 8-14 mu m were further investigated. The data demonstrated that the SPA@QDs-15 composite film possessed an infrared emissivity value of 0.501, which was much lower than pristine SPA and QDs. This might be attributed to the incorporation of optically active helical SPA and semiconductor QDs in a hybrid phase, which had great effect in enhancing their interfacial interactions.