Computational Study of Chemical Reactions and Material Modification during Polyatomic-Ion and Cluster-Surface Deposition

佛罗里达大学的苏珊·辛诺特得到了理论和计算化学计划的支持，该计划利用分子动力学(MD)模拟来研究粒子-表面相互作用，这些相互作用可能导致化学反应和材料修改。我们将研究三个密切相关的问题。首先，我们将研究共价结合的多原子离子在聚合物衬底上的沉积。多原子离子在材料改性和薄膜生长方面的独特能力推动了这项研究，旨在揭示发生在低能等离子体中的类似和更复杂的过程。其次，将探索使用多原子和单原子离子对碳纳米管和纳米管-聚合物界面进行化学功能化和改性，这是因为碳纳米管正被考虑用作下一代复合材料的纤维。最后，将研究气体溶剂辅助化学中分子团簇沉积在固体表面时发生的新的特定尺寸的反应，以及通过团束沉积可以实验上生成的共价平衡的纳米结构薄膜的生长。该项目要求对现有的MD程序进行扩展和改进，以包括热表面扩散的动力学蒙特卡罗模拟和每个团簇沉积事件的MD模拟之间的松弛。在所有三个项目上，都计划与实验者和理论家合作。这一计算项目有可能提供新的理解，这对工业材料加工将是重要的。例如，离子沉积可以作为通过低能量等离子体生长薄膜的几个方面的模型，这是在干燥条件下沉积聚合物薄膜的主要工业方法。有机薄膜在光电子应用、涂层、电子器件和机械应用中具有重要意义。本研究旨在模拟与正在进行的实验研究相关的薄膜沉积和表面改性问题。

Susan Sinnott of the University of Florida is supported by the Theoretical and Computational Chemistry Program to examine particle-surface interactions that can lead to chemical reactions and material modification using molecular dynamics (MD) simulations. Three closely related problems will be studied. First, the deposition of covalently bound polyatomic ions on polymeric substrates will be examined. The unique capabilities of polyatomic ions for material modification and thin-film growth motivate this research, which aims to shed light on the analogous and more complex processes that take place in low-energy plasmas. Second, the use of polyatomic and single-atom ions to chemically functionalize and modify carbon nanotubes and nanotube-polymer interfaces will be explored, motivated by the fact that carbon nanotubes are being considered for use as fibers in the next generation of composite materials. Finally, the novel size-specific reactions that occur in gas solvent assisted chemistry when molecular clusters are deposited on solid surfaces will be studied, along with the growth of covalently balanced nanostructured thin films that can be generated experimentally through cluster-beam deposition. This project requires expansion and refinement of existing MD programs to include kinetic Monte Carlo simulations of thermal surface diffusion and relaxation between MD simulations of each cluster deposition event. Collaborative efforts are planned with experimentalists and theorists on all three projects. This computational project has the potential to provide new understanding that will be important for industrial materials processing. For example, ion deposition can serve as a model for several aspects of thin-film growth through low energy plasmas, which is the leading industrial method for depositing polymer thin films under dry conditions. Organic thin films are important for optoelectronic applications, coatings, electronic devices, and mechanical applications. The present studies aim to model film deposition and surface modification issues relevant to ongoing experimental studies.