Ionic Nanoconvection in Anodization of Aluminum Plate and Formation of Si nanowires

本研究系关于在铝板阳极化制程中建立一种新颖的离子奈米对流。该模型是基于近世纪前建立的传统Rayleigh-Benard热对流模型的修改，现在首次用于纳米系统。阳极氧化铝（AAO）是制备纳米材料（包括纳米线）的常用模板。其高度有序孔的形成机理已经研究了50多年。与以往的模型相比，我们的离子纳米对流模型具有一些优点，因为我们可以揭示AAO中有序孔形成的本质，并阐明阳极电压、阳极电流密度、阳极时间、用作电解质的酸溶液浓度我们期望，在我们的模型建立后，铝板的阳极氧化将变得更加可控。我们将研究在AAO中制备的Si纳米线的微观结构，并重点关注一些新类型的缺陷，例如孪晶缺陷的厚边界，超结构，表面涂层的详细结构和表面再结晶。硅纳米线的拉曼散射也将被研究。这一研究将使我们对硅纳米线的形成机理和性质有更好的了解。

The proposed research is about an establishment of a novel ionic nanoconvection in the anodization process of aluminium plates. The model is based on a modification of the traditional Rayleigh-Benard thermal convection model established nearly one century ago and is now used in a nanoscale system for the first time. Anodic aluminium oxide (AAO) is a common template for preparing nanomaterials including nanowires. The formation mechanism of its highly ordered pores has been investigated for more than 50 years. Our ionic nanoconvection model has several advantages in comparison with the previous ones because we may reveal the nature of the formation of the ordered pores in AAO and elucidate the various effects on this process, such as anodic voltage, anodic current density, anodic time, concentration of the acid solution used as electrolyte, etc. We expect that the anodization of Al plates will become much more controllable after the establishment of our model. We will investigate the microstructures of Si nanowires made in AAO and focus on some new types of defects, e.g. thick boundaries of twin defects, superstructures, detailed structures of surface coating layers and surface recrystallization. Raman scattering of the Si nanowires will also be investigated. This research will allow us to have a better understanding of the formation mechanism and properties of Si nanowires.