Question

Consider the following processes:

1. Sol-gel process

2. Electrodeposition

3. Plasma-enhanced vapour decomposition

4. Gas-phase condensation

5. Sputtering technique

The above processes are related to
1. analysis of nano-powders
2. sintering of nano-powders
3. synthesis of nano-powders
4. microwave sintering of nano-powders

Answer 1

Correct Answer - Option 3 : synthesis of nano-powders

The processes, related to the synthesis of nanopowders are:

Sol-gel process:

• It is a process for producing solid material from small molecules.
• This method is used for the fabrication of metal oxides, especially the oxides of silicon and titanium.

Electrodeposition:

• It is a process to produce situ metallic coating by the action of an electric current on a conductive material in a solution containing a salt of the metal to be deposited.

Plasma enhanced vapour decomposition:

• It is a process used to deposit thin films from a gas state (vapour) to a solid-state on a substrate.
• The plasma is generally created by radiofrequency discharge between two electrodes.
• The space between two electrodes is filled with reacting gases.

Gas-phase condensation:

• It uses a vacuum chamber that consists of a heating element, the metal to be made into nanopowder, powder collection equipment and vacuum hardware.
• Due to heated element, metal is melted rapidly, as the gas cools the metal vapour, nanometre-sized particles.

Sputtering technique:

• It is a process in which microscopic particles of solid material are injected from its surface after the material is itself bombarded by energetic particles of a gas.
• It occurs naturally in the outer environment.