在三十年的强力加载率中观察到的-碳键的动态强度
Sebastian W Schmidt1, Martin K Beyer, Hauke Clausen-Schaumann
1Department of Precision- and Micro-Engineering, Engineering Physics, University of Applied Sciences München, Lothstrasse 34, 80335 Munich, Germany.
Journal of the American Chemical Society
|February 28, 2008
概括
-碳键的机械强度随着力量加载率的增加而增加,正如原子力显微镜所显示的那样. 这项研究量化了键断裂力,并探索了用于预测压力下的材料行为的理论模型.
科学领域:
- 材料科学 材料科学 材料科学
- 化学物理 化学物理
- 纳米技术纳米技术
背景情况:
- 了解化学键的机械性质对于材料科学至关重要.
- -碳 (Si-C) 键在各种材料中是基本的,但它们在动态负载下的机械强度尚未完全表征.
研究的目的:
- 通过实验确定单个Si-C键的机械强度.
- 为了研究应用力加载率和Si-C键破裂力之间的关系.
- 评估用于预测债券行为的理论模型.
主要方法:
- 使用原子力显微镜 (AFM) 进行动态单分子力谱.
- 应用的强力加载速率在三个数量级 (0.5到267nN/s) 上有所不同.
- 使用基于阿雷尼乌斯动力学和结合潜力的三个理论模型进行分析.
主要成果:
- 观察到Si-C键破裂力随着强力加载率的增加而增加的对数增长.
- 平均破裂力在0.5nN/s时为1.1nN,在267nN/s时为1.8nN.
- 摩尔斯电位模型符合产生的参数fmax = 2.0-4.8nN和D(e) = 76-87kJ/mol.
结论:
- 实验数据与阿雷尼乌斯动力学关于键断裂的预测一致.
- 理论模型复制实验数据,但缺乏参数明确性.
- 从气相计算中得出的参数与实验观察结果不匹配,这突显了实验验证的重要性.
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