从胺中合成的自下而上的HPHT纳米钻石的形态和性质的转变
Stepan Stehlik1,2, Petr Belsky2, Tomas Kovarik2,3
1Institute of Physics of the Czech Academy of Sciences Prague Czech Republic stehlik@fzu.cz.
Nanoscale advances
|March 17, 2025
概括
从底部向上的高压高温 (BU_HPHT) 合成产生纳米钻石 (ND). 在900°C以下,ND是二维血小板;在900°C以上,它们成为纳米晶体,表现出独特的特性.
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:
- 直接自下而上的高压高温 (BU_HPHT) 合成通过温度来控制纳米钻石 (ND) 尺寸.
- 了解尺寸依赖性属性对于定制ND应用至关重要.
研究的目的:
- 研究BU_HPHT NDs的大小依赖的热,体和结构性质.
- 在900°C (大约2nm) 周围的形态和属性过渡的特征.
主要方法:
- 传输电子显微镜 (TEM) 用于形态学.
- 用于结构分析的小角度X射线散射 (SAXS).
- 原子力显微镜 (AFM) 和泽塔电位测量用于合性质.
- 在现场拉曼光谱仪用于热稳定性.
主要成果:
- 低于900°C的样本 (<2nm NDs) 呈现出具有亚纳米厚度的2D血小板形态,而不是纳米粒子特征.
- 这些较小的结构是疏水的,具有负泽塔潜力,类似于分子钻石.
- 在-900°C以上的样本 (>2nm NDs) 显示纳米晶体特性,正色达电位和水分散性.
- 在现场拉曼光谱学揭示了在过渡温度下氧化亚2纳米BU_HPHT NDs中的结构不稳定性.
结论:
- 在BU_HPHT NDs中,在900°C (≈2 nm) 左右,发生了形态和性质的明显转变.
- 2nm以下的ND表现为2D分子钻石结构,而较大的ND则是纳米晶体.
- 过渡与结构不稳定性有关,并影响着体行为和分散性.
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