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对晶体生长机制、动力学与微结构衍化的认识是实现纳米材料的尺寸和形貌可控制备的基础.以表面溶解沉积为特征的奥斯特瓦尔德熟化(OR)理论常用来解释传统的晶体生长过程.在该生长模式下,纳米晶体的生长呈现出小颗粒溶解而大颗粒逐渐长大的特征.在纳米材料体系,近来还发现了一种重要的新的晶体生长模式——“取向接合(OA)”机制,在该机制下,两个晶格取向一致的初级纳米颗粒可通过直接接合和结构调整,从而长成一个新的晶体.这一机制已被证实在许多纳米材料体系中广泛存在,并对所合成的纳米材料的形貌、微结构具有非常显著的影响,在构筑新型纳米结构方面具有潜在的优势.本文我们首先回顾了OA生长机制的认识历程和这一机制对材料科学的重大意义;进而,基于我们的研究工作系统介绍了OA生长动力学模型的建立与发展,进一步阐述了这一机制的微观过程及其对材料内部缺陷的特殊影响,深入地分析和讨论了表面包裹的强弱、表面作用的性质对OR机制和OA机制的抑制和调控作用;基于上述表面包裹可调控纳米材料的生长机制的认识,我们结合近期研究结果,从动力学角度分析了量子点的生长机制与其发光特性的内在关联,阐明了表面包裹调控量子点的发光性质的本质原因,为制备不同发光特征的量子点及理解其发光性质衍化规律提供了重要的理论指引.
The understanding of crystal growth mechanism, kinetics and microstructure evolution is the basis for the controlled preparation of nanomaterials in size and morphology.The Ostwald ripening (OR) theory, characterized by surface dissolution and deposition, is often used to explain the traditional In the growth mode, the growth of nanocrystals is characterized by the dissolution of small particles and the gradual growth of large particles.In the nanomaterials system, an important new crystal growth mode has recently been discovered - Oriented Alignment (OA) "mechanism, in which two primary crystal-aligned primary nanoparticles can grow into a new crystal by direct bonding and structural modification.This mechanism has been demonstrated in many nanomaterials System and has a very significant effect on the morphology and microstructure of the synthesized nanomaterials and has potential advantages in constructing new nanostructures.In this paper, we first review the cognitive mechanism of OA growth mechanism and this mechanism Which is of great significance to material science. Furthermore, based on our research work, the establishment and development of OA growth dynamics model are introduced systematically, and the mechanism of Micro-processes and their special effects on the internal defects of the material, in-depth analysis and discussion of the strength of the surface package, the nature of the surface effects on the OR mechanism and inhibition of OA mechanism and regulation; based on the above surface can be controlled by the growth of nano-materials Mechanism, we combine the recent research results, from the kinetic point of view of the inherent mechanism of quantum dot growth mechanism and its light-emitting characteristics of the nature of the light-emitting nature of the regulation of quantum dots surface elucidation of quantum dots for the preparation of different quantum dots And understanding of its law of evolution of the luminous properties provide an important theoretical guidance.