"Diamondoids are the molecular building blocks of nanomaterials", this statement is frequently found in many published articles. The examples that are given are usually material of diamond or zinc blende materials. Are there any other building blocks for wurtzite, monoclinic etc..?
The Diamond is composed of only carbon arranged in its unit cell which in what is called face centered cubic and the bonding between the carbon atoms are the strong covalent bonds.. and it is considered as a mineral , there are other polymorphs present for the carbon elements ( i.e the same elements ( Carbon) arranged it self in a different unit cell shape and these different polymorphs have different structure and different properties. These polymorphs are ( Graphite, Fuulereen, Lonsdale which is a rare mineral different from Diamond There are also the amorphous phase of carbon which has no unit cell or unit Bloch. The structure of Silicon is exactly similar to Diamond but its properties is different and its finger print is differentent ( we know that by X-Ray diffraction
if you find the following statement ( Diamondoids are the molecular building blocks of nanomaterials) ( which is completely a wrong statement because the block here means the structure of the unit cell of diamond in any nano-materials ) The person who put this statement wants to misleads the Scientist. The author who put this statement is not crystallographer and accordingly he might think that the shape of the nano particles is similar to the outer shape of the diamond crystal ( the crystals are formed from bilion blocks) because the different arrangement of the outer faces of a diamond crystal tend to make its shape approximately similar to sphere. This means that the statement has nothing to do with the structures of the materials) the structure of the nano materials is exactly similar to the structure of its crystalline materials or other wise all the prepared nano materials if it has the same structure as diamond it will give the same properties and this is not the case. The statment ( Diamondoids are the molecular building blocks of nanomaterials) is misleading and should be replaced by Spherical in shape. Blocks mean the unit cell and the unit cell contain the structural arrangement and there is not any two materials in the world of different elements which have the same structures. Structure is a finger print for each material .
Probably term "nanomaterials" allow wide treatment. To my opinion it may include so called intergrowth ("misfit") materials which construct as conseqense of blocks MX and TX2, where MX - layers with rocksalt structure and TX2 - layer with structure of CdI2 or NbS2. Moreover politypes with consequence TX2-MX-TX2-TX2-MX-TX2 are known and in these materials gap TX2-TX2 may be intercalated another metals. Structure of this layer may be hexagonal or monoclinic. So this materials may be constructed from layers with rocksalt structure, hexagonal or trigonal layers and hexagonal or monoclinic layers.
Dear Titov
Thanks for your answer. Hexagonal should be the nearest to diamond structure so that I anticipated that we might have such blocks at least in this structure.
I believe, it is quite possible from the structural point of view. However, for successful interface blocks have to form a chemical bond. It imposes restrictions on the chemical nature of blocks. For diamondlike structures the saturated covalent bonds doing them chemically inert are characteristic. Therefore I doubt that such blocks participated in formation of nanomaterials. On the other hand, structure of diamond can have various not - carbon materials. In them such problems are absent.
It is important to note that in the misfit materials interface of blocks with different structure possibly in the presence of free electrons. In a case if materials диэлектричны, the material becomes a uniform ferroelectric material.
The monoclinic layer turns out from hexagonal when filling a half or one quarter of positions. Therefore such blocks easily unite in the general structure.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology