Explanation

It is also called orientation adhesion or orientation epiphyte. It was proposed jointly by Penn and Banfield to describe the process of synthesis of nanomaterials. In order to reduce its own surface free energy and grain boundary energy, the primary nanoparticle spontaneously organize, connect, and rotate to the orientation of the common crystal plane to form a coherent grain boundary. The process of producing larger crystal with uniform orientation. In this process, nanoparticle and adjacent grains grow or coalesce linearly by eliminating their common boundaries. Unlike the Ostwald ripening process in which the basic structural unit is atoms or ions, the basic structural unit of oriented attachment is the pre formed primary nanoparticle. This growth mechanism mainly occurs between freely movable nanoparticle, such as colloidal particles in solution or particles nucleating adjacent to each other on the substrate. The local characteristic of oriented attachment is that nanoparticles can form in an irregular form. The research shows that the mechanism of oriented attachment is very important, especially in the early growth stage of nanocrystals. This mechanism has been theoretically studied and experimentally validated in the study of micro metal and oxide systems. In recent years, as an important growth mechanism of nanomaterials, oriented attachment has been widely used to prepare functional nanomaterials with controllable morphology and properties, which is of great significance in both basic research and application research fields.

Classification