Simultaneous photoluminescence import and mechanical enhancement of polymer films using silica-hybridized quantum dots
Simultaneous photoluminescence import and mechanical enhancement of polymer films using silica-hybridized quantum dots
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DOI：
10.1039/c0jm00211a
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发表时间：
2010-06
影响因子：
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通讯作者：
Li Zhou;Li Zhou;Chao Gao;Weijian Xu
中科院分区：
文献类型：
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作者：
Li Zhou;Li Zhou;Chao Gao;Weijian Xu
首次提出了基于超小二氧化硅杂化的CdTe量子点（SiO2-h-QDs）或甲基丙烯酸3-（三甲氧基硅基）丙酯改性的SiO2-h-QDs（SiO2-h-QD-MSMA）与聚合物的简单共混的量子点-聚合物纳米复合材料，其同时具有稳定的光致发光和增强的机械性能。典型地，对于SiO2-h-QD-MSMA/聚（甲基丙烯酸甲酯）（PMMA）纳米复合材料膜，在仅加载0.2wt%的SiO2-h-QD-MSMA时，拉伸强度、杨氏模量和断裂伸长率分别提高了约46%、74%和6%。结果表明，由于SiO2-h-QD与聚合物基体之间的界面结合力以及纳米填料在复合材料中的良好分散性，SiO2-h-QD对亲水性聚合物（如聚乙烯醇）和疏水性聚合物（如聚甲基丙烯酸甲酯或聚苯乙烯）的力学增强效应具有普遍性。SEM测量表明，材料的韧性断裂行为，其中表面改性的纳米填料与聚合物基体是很好的相容性，但脆性断裂行为与原始的纳米填料加载的复合材料，由于它们的局部聚集。二氧化硅杂化量子点的负载同时赋予复合材料所需的和稳定的光学性质。即使在日光下暴露一年，纳米复合薄膜的光致发光和透明度也没有明显的下降。这种双功能SiO2-h-QD-聚合物纳米复合材料有望提升传统聚合物材料的潜力。
Quantum dot (QD)-polymer nanocomposites that simultaneously possess stable photoluminescence and enhanced mechanical properties are presented for the first time based on the facile blending of the ultrasmall silica-hybridized CdTe QDs (SiO2-h-QDs) or 3-(trimethoxysilyl)propyl methacrylate-modified SiO2-h-QDs (SiO2-h-QD-MSMAs) with polymer. Typically, for SiO2-h-QD-MSMA/poly(methyl methacrylate) (PMMA) nanocomposite films, the tensile strength, Young's modulus, and elongation at break improved by about 46%, 74% and 6%, respectively, upon the loading of only 0.2 wt% of SiO2-h-QD-MSMAs. It is found that the mechanical enhancement effect of the silica-hybridized QDs is general for both hydrophilic polymers such as polyvinyl alcohol and hydrophobic polymers such as PMMA or polystyrene due to the strong interfacial adhesion between SiO2-h-QDs and polymer matrix as well as the fine dispersibility of the nanofillers in composites. SEM measurements showed a ductile-rupture behavior for the materials in which the surface-modified nanofillers were well compatible with the polymer matrix, but a brittle-rupture behavior for the composites loaded with pristine nanofillers due to their local aggregation. The loading of silica-hybridized QDs simultaneously endowed the composites with desired and stable optical properties. No obvious decreases of both photoluminescence and transparency were found for the nanocomposite films exposed to daylight even for one year. Such dual functional SiO2-h-QD-polymer nanocomposites promise great potential to upgrade the conventional polymer materials.