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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (8): 985-989. 上一篇    下一篇

研究论文

溶剂对聚酰胺-胺树形分子模板法原位制备CdS量子点的影响

丛日敏*,1,2，罗运军*,2，于怀清1   

  1. (1山东理工大学材料科学与工程学院 淄博 255049)
    (2北京理工大学材料科学与工程学院 北京 100081)
  • 投稿日期:2007-09-04 修回日期:2007-11-10 发布日期:2008-04-28
  • 通讯作者: 丛日敏

Effects of Solvent on the in situ Preparation of CdS Quantum Dots Using PAMAM Dendrimer Templates

CONG Ri-Min*,1,2 LUO Yun-Jun*,2 YU Huai-Qing1   

  1. (1 School of Material Science and Engineering, Shandong University of Technology, Zibo 255049)
    (2 School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081)
  • Received:2007-09-04 Revised:2007-11-10 Published:2008-04-28
  • Contact: CONG Ri-Min

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699

被引次数

10

为了研究非配位型溶剂对聚酰胺-胺(PAMAM)树形分子的模板法制备CdS量子点的影响, 分别以水、甲醇及二者的混合物( ∶ ＝2∶1)为溶剂, 以4.5代PAMAM树形分子为模板制备了CdS量子点. 结果表明, 相同条件下, 以甲醇为溶剂时制备的CdS量子点为单晶, 平均直径2.7 nm, 尺寸分布窄, 发光强度高; 以水为溶剂制备的CdS量子点为多晶, 平均直径为5.7 nm, 尺寸分布宽, 发光强度低; 在甲醇与水的混合溶剂中制备的CdS量子点为单晶和多晶共存, 平均直径为4.1 nm, 尺寸分布及发光强度都居中. 这主要是由于树形分子的模板作用不同造成的. 树形分子在甲醇中能充分伸展, 起到内模板作用; 树形分子与水之间由双氢键作用而产生交联, 不利于Cd2＋与树形分子内部基团的配位, 主要起到外模板作用; 在甲醇与水的混合溶剂中, 树形分子则同时起到了内模板和外模板作用.

关键词: PAMAM树形分子, CdS量子点, 溶剂, 模板作用

In order to study the effects of non-coordinated solvents on the in situ preparation of CdS quantum dots (QDs) using poly(amidoamine) (PAMAM) dendrimer templates, well-dispersed CdS QDs were synthesized using PAMAM dendrimers of generation 4.5 (G4.5, 64 terminal ester groups) as templates in following solvents: methanol, water, the mixture of methanol and water (VCH3OH∶VH2O＝2∶1). CdS QDs prepared in methanol are single crystals and the average diameter is 2.7 nm, and besides, their size-distribution is the narrowest and photoluminescence (PL) is the strongest. While CdS QDs prepared in water are polycrystals and the average diameter is as large as 5.7 nm, furthermore, their size-distribution is the broadest and PL intensity is the weakest. However, CdS QDs prepared in the mixed solvent are composed of single crystals and polycrystals, the average diameter is 4.1 nm, and the size-distribution and PL intensity are middling. These differences were attributed to the different template effects of the PAMAM dendrimers. The branches of the dendrimers can extend freely in methanol, which makes the dendrimers inner templates. While in water, the dendrimer-water cross-linked structures built through double hydrogen bonds prevent Cd2＋ from coordinating with the inner groups of the dendrimers, which makes the dendrimers exterior templates mainly. Therefore, dendrimers act as inner templates and exterior templates simultaneously in the mixed solvent.

Key words: PAMAM dendrimer, CdS quantum dot, solvent, template effect