How do we know that the our materials are nanomaterials?

How do we detect the nanomaterials such as NPs, NFs, NRs, NTs, sheet, or 0D, 1D, 2D, 3D.

How do we know that synthesized materials are at nanoscale.

Let's first understand the word Nano

Nano - Any material of any shape having any dimension (x, y, and z) in the range of 1- 100 nm. i.e., if any dimension of the material is below 100 nm, the materials are called nanomaterials.

The terms Crystallite Size, Grain Size, and Particle Size also come in the nanoworld domain. There is a relation among these terms

Crystallite Size ≤ Grain Size ≤ Particle Size

The following characterization techniques are helpful to observe and detect nanomaterials:

1. Scanning electron microscopy (SEM)
2. Field emission SEM (FESEM)
3. Transmission electron microscopy (TEM), HRTEM
4. Scanning Transmission electron microscopy (STEM)
5. Electron Backscatter Diffraction (EBSD)
6. Magnetic susceptibility

The word dimension or dimensionality simply refers to size, length, diameter, or radius. Mostly, the dimension is represented by x, y, or z –axis in a coordinate system. As we know, an object has maximum x, y, and z axis where these three dimensions (x, y, and z axis) are further used to calculate the area and volume.

Now let’s discuss the four types of nanomaterials such as zero dimensional (0D), one dimensional (1D), two dimensional (2D), and three dimensional (3D)

Zero-dimension (0D) nanomaterials:

If all the 3 dimensions (x, y, and z axis) are in the range of 1-100 nm called 0D nanomaterials. Such as nanoparticles, quantum dots, carbon dots……

One-dimensional (1D) nanomaterials:

If one of the dimensions is beyond 100 nm or two of its dimensions are in the range of 1-100 nm. Simply saying that the x-axis is below 100 nm, the y-axis is below 100 nm, BUT the z-axis is above 100 nm. Such materials are classified as 1D. For example, nanotube, nanorods, nanofibers, etc.

Two-dimensional (2D) nanomaterials:

If two of the dimensions are beyond 100 nm. Simply saying x-axis is below 100 nm, y and z- axis are above 100 nm. Such nanomaterials refer to 2D. For instance, 2D sheet of graphene, 2D sheet of MXenes, …

Three-dimensional (3D) nanomaterials:

If all three dimensions are beyond 100 nm. Why then are they called 3D nanomaterials? It is due to the fact that the powder form of the materials is ultimately comprised of nanomaterials. Another example is flowers' shapes, which are made of leaves, etc, and they are well below 100 nm…..