Nanocapsules are capsules on the nanometer scale (one billionth of a meter). When the matter is 1 nanometer = 10-9 meters, the mass is as small as 1 to 100 nanometers (10-9-10-7 meters). Due to its quantum effect, the locality of the material and the huge surface and interface effects, there will be a lot of material The performance has undergone a qualitative change, presenting many strange phenomena that are different from macroscopic objects and individual isolated atoms.
Nanocapsules are an important branch of nanomaterials and an important part of zero-dimensional nanomaterials. Nanocapsules can be regarded as an extension of the concept of microcapsules, and microcapsules have long been a very mature and huge industry in terms of synthesis technology and practical applications. Traditional medicine capsules encapsulate medicines in a protective shell to form a core with certain functions. Therefore, borrowing the concept of "capsule" has the characteristics of a shell/core structure, and the inclusions of metals, non-metals and organics with shell/core structure characteristics in various scales between 1-100nm are collectively referred to as " Nanocapsules". We usually take cold capsules when we take medicine for colds. We can imagine reducing cold capsules to nanometer scale (between 1 nanometer and 100 nanometers). We can also imagine shrinking eggs to the nanometer scale.
There are many types of nanocapsules. Shell materials include graphite, CNx, boron nitride, disulfide (MX2, M = W, Mo, Nb, Ta; X = S, Se, Te) and other layered materials, high molecular polymers and phosphates, SiO2, Semiconductor, oxide, etc. The core materials include various metals, non-metal elements and compounds. As a mesoscopic system between macroscopic objects and atoms, nanocapsules have something in common with macroscopic objects and atoms, but also have many unique properties and uses. It combines the characteristics brought by the core-shell structure and the effect of the nanosystem caused by the size change. The outer shell of the nanocapsule has many functions, such as: protecting the inner core from environmental damage; increasing the stability of nanoclusters to prevent their growth; promoting the dispersion of nanoparticles in different media; increasing the activity of substances; changing the inner core Optical, electrical, magnetic properties, etc.