热力学稳定的合体固体:从粒子大小分布的界面热力学
Andrew Nelson1, Lawrence H Friedman1
1Materials Measurement Science Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899.
概括
这项研究将经典核化理论应用于体系统,揭示了尺寸依赖的界面自由能量,这对于理解纳米粒子稳定性至关重要. 研究结果表明,一些系统可能是超稳定的,而不是绝对稳定的.
科学领域:
- 合体和表面科学科学
- 材料化学 材料化学
- 热力学是一种热力学.
背景情况:
- 在固体合溶液分散中,真正的热力学稳定性是罕见的,并且研究不足.
- 了解长期稳定性和准备途径不敏感性是非常有趣的.
- 现有的模型通常假定绝对热力学稳定性,这可能不是真的.
研究的目的:
- 将经典核化理论 (CNT) 应用于体系统,以将粒子大小分布与大小依赖的界面自由能量联系起来.
- 为了适应使用CNT的纳米粒子大小分布的实验数据.
- 为了研究金-硫醇和磁铁的纳米粒子系统的热力学稳定性.
主要方法:
- 应用经典核化理论 (CNT) 来建模体系统.
- 与粒子大小分布相关的界面自由能量密度.
- 通过使用CNT. 拟合金-醇和磁石纳米颗粒的实验尺寸分布数据.
主要成果:
- 黄金-醇系统数据与界面自由能量 (γ) 很好地匹配,遵循r−3.3的功率定律.
- 磁铁纳米粒子数据与CNT很好地匹配,其中γ遵循r-2.2的功率定律.
- 额外推算的平面自由能量密度很小并且是正的;系统看起来非常稳定.
结论:
- 经典核化理论有效地描述了体系统中尺寸依赖的界面自由能量.
- 研究的黄金-醇和磁铁系统可能是超稳定的,挑战绝对稳定的假设.
- 界面能量参数的衍生表达式,适用于未来对表面活性剂度,温度和粒子分布的研究.
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