论文标题

金纳米颗粒的机械化学合成的热力学模型:对无溶剂纳米颗粒的影响

A Thermodynamics Model for Mechanochemical Synthesis of Gold Nanoparticles: Implications for Solvent-free Nanoparticle Production

论文作者

Yang, Lin, Moores, Audrey, Friščić, Tomislav, Provatas, Nikolas

论文摘要

机械化学已成为一种既定的方法,用于纳米材料和分子评分的可持续固相合成,范围从活性药物成分到清洁技术的材料。然而,我们仍然缺乏一个良好的模型来合理化实验观察,并在机械辅助,固相纳米颗粒合成过程中对起作用的因素有一种机械理解。我们在本文中提出了一个结构相 - 场 - 晶体(XPFC)模型,该模型具有弹道驱动力来描述这种过程,其中具有两个组分混合物中金纳米颗粒生长的具体示例。反应路径在模型的自由能格局的背景下进行了描述,并且基于与实验条件的现象学模型参数进行动力学模拟,以得出对纳米颗粒生长动力学的结论。结果表明,弹道术语降低了反应的激活能屏障,从而使温度与实验观测的温度兼容。该模型还解释了与实验观察一致的沉淀晶粒尺寸减少的机制。我们的仿真结果提供了对机械合成的新机械见解,对纳米颗粒的产生及其他产品有影响。

Mechanochemistry is becoming an established method for the sustainable, solid-phase synthesis of scores of nano-materials and molecules, ranging from active pharmaceutical ingredients to materials for cleantech. Yet we are still lacking a good model to rationalize experimental observations and develop a mechanistic understanding of the factors at play during mechanically assisted, solid-phase nanoparticle synthesis. We propose herein a structural-phase-field-crystal (XPFC) model with a ballistic driving force to describe such a process, with the specific example of the growth of gold nanoparticles in a two component mixture. The reaction path is described in the context of free energy landscape of the model, and dynamical simulations are performed based on phenomenological model parameters closely corresponding to the experimental conditions, so as to draw conclusions on nanoparticle growth dynamics. It is shown that the ballistic term lowers the activation energy barrier of reaction, enabling the reaction in a temperature regime compatible with experimental observations. The model also explains the mechanism of precipitated grain size reduction that is consistent with experimental observations. Our simulation results afford novel mechanistic insights into mechanosynthesis with implications for nanaparticle production and beyond.

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