纳米晶体在随机包装的薄膜和长距离有序超级网中通过时间解析的小角度X射线散射进行结构性行为的比较
Byeongdu Lee1, Paul Podsiadlo, Sara Rupich
1Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
Journal of the American Chemical Society
|October 30, 2009
概括
我们使用时间解析小角度X射线散射 (SAXS) 来研究纳米晶体固体. 面状晶体显示的粒子间距比无序的膜更小,影响了分子包装.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 物理化学 物理化学
背景情况:
- 纳米晶体 (NC) 固体对各种应用具有前景.
- 控制粒子间距对于调整材料特性至关重要.
- 无核固体的结构可以从无序的薄膜到有序的晶体.
研究的目的:
- 为了比较纳米晶体固体的不同排列中的晶格结构和粒子间距.
- 为了研究晶体结构对分子包装的影响.
- 探索操纵粒子间距的方法.
主要方法:
- 使用时间解析的小角度X射线散射 (SAXS).
- 该研究的重点是7纳米的PbS纳米晶体,覆盖有油酸.
- 分析了不同的固态包装结构:随机包装的薄膜,周期性薄膜和3D晶体.
主要成果:
- 与溶剂蒸发的3D片相比,有面的3D晶体显示的粒子间距大约小了25%.
- 面状晶体中的粒子间距比油酸分子的延长长度小,这表明有限的数字间距.
- 温和的热处理被证明可以进一步改变粒子间距.
结论:
- 包装结构显著影响纳米晶体固体中的粒子间距.
- 由于间距较小,在面状3D晶体中可能存在有限的分子间位.
- 准备后热处理提供了一条控制纳米晶体固体结构的途径.
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