PbS/Polymer Nanocomposite Optical Materials with High Refractive Index

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• 作者：Changli Lü ; Cheng Guan ; Yifei Liu ; Yuanrong Cheng ; and Bai Yang
• 刊名：Chemistry of Materials
• 出版年：2005
• 出版时间：May 3, 2005
• 年：2005
• 卷：17
• 期：9
• 页码：2448 - 2454
• 全文大小：280K
• 年卷期：v.17,no.9(May 3, 2005)
• ISSN：1520-5002

文摘

High refractive index nano-PbS/polymer composites were fabricated from reactive lead-containingprecursors and polythiourethane (PTU) oligomer terminated with isocyanate group, followed by in situgas/solid reaction. The lead-containing precursor with a chemical formula of Pb(SCH₂CH₂OH)₂ wassynthesized in water phase at pH = 5-9 and exhibited an absorption at 317 nm in dimethyl sulfoxide(DMSO) in UV-vis spectra. PbS nanoparticles can be formed in DMSO after treatment with H₂S. TEMstudies indicated that the PbS nanoparticles were smaller than 10 nm and aggregated seriously in DMSO.After the precursors were incorporated into PTU oligomer, the obtained composite films were treatedwith H₂S to obtain PbS nanoparticles/PTU nanocomposite films. TEM showed that the nanocompositesexhibited interesting phase behaviors depending on the precursor content in films. A uniform sphericalaggregate of PbS nanoparticles (nanospheres) with a size smaller than 100 nm formed in the nanocompositefilms below 26.3 wt % of lead-containing precursors. When the precursor content was larger than 59.3wt %, the PbS nanoparticles about 3 nm dispersed uniformly in the whole polymer matrix. Ellipsometricmeasurement indicated that the precursors/PTU composite films before being treated with H₂S had arefractive index in the range 1.57-1.665 and after reaction with H₂S, the obtained PbS/PTU nanocompositefilms had a higher refractive index in the range 1.57-2.06 with the varied content of precursors from 0to 67 wt %.