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

佛罗里达大学的Susan Sinnott得到了理论和计算化学项目的支持，使用分子动力学（MD）模拟来研究可能导致化学反应和材料改性的颗粒表面相互作用。 将研究三个密切相关的问题。 首先，将检查共价结合的多原子离子在聚合物基底上的沉积。 多原子离子用于材料改性和薄膜生长的独特能力激发了这项研究，旨在揭示低能等离子体中发生的类似和更复杂的过程。 第二，将探索使用多原子和单原子离子化学官能化和改性碳纳米管和纳米管-聚合物界面，其动机是碳纳米管被考虑用作下一代复合材料中的纤维。 最后，将研究当分子团簇沉积在固体表面上时，在气体溶剂辅助化学中发生的新颖的尺寸特异性反应，沿着可以通过团簇束沉积实验产生的共价平衡的纳米结构薄膜的生长。 该项目需要扩展和完善现有的MD程序，包括动力学蒙特卡罗模拟的热表面扩散和放松之间的MD模拟每个集群沉积事件。 计划在所有三个项目上与实验者和理论家进行合作。这个计算项目有可能提供新的理解，这将是重要的工业材料加工。 例如，离子沉积可以作为通过低能等离子体的薄膜生长的几个方面的模型，低能等离子体是在干燥条件下沉积聚合物薄膜的领先工业方法。 有机薄膜在光电应用、涂层、电子器件和机械应用中是重要的。 本研究的目的是模型膜沉积和表面改性相关的正在进行的实验研究的问题。

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.