Context:
A novel method for sodium catalyzed synthesis of carbon nanotubes (CNTs) on glass substrates has been developed
Carbon Nanotubes (CNTs):
- Hollow tubes composed of carbon atoms with diameter on nanoscale
- They are composed of rolled-up graphene sheets.
- According to carbon shells divided into –
- Single-walled (SWCNT) – A long tube formed by wrapping a single graphene sheet into a cylinder with diameter of 1 nanometer and ends capped by fullerene cages.
- Multi-walled (MWCNT) – Concentrically aligned SWNT assemblies with different diameters
- Properties – High surface to volume ratios, enhanced conductivity and strength, biocompatibility, etc.
- Applications – Rechargeable batteries, flexible electronics, aerospace, energy research, biomedical fields and optoelectronics
- Synthesis of CNTs by – Plasma Enhanced Chemical Vapour Deposition (PECVD) technology
Plasma Enhanced Chemical Vapour Deposition (PECVD):
- A chemical vapor deposition process that deposits thin films from a gas state to a solid state on a substrate.
- Significance –
- Low deposition temperature – Deposits thin films of carbon-based materials.
- High deposition efficiency – Offers high-purity and high-crystalline graphene.
Source: PIB
Previous Year Question
Consider the following statements:
1. Other than those made by humans, nanoparticles do not exist in nature.
2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics.
3. Nanoparticles of same commercial products which enter the environment are unsafe for humans.
Which of the statements given above is/are correct?
[UPSC Civil Services Exam – 2014 Prelims]
(a) 1 only
(b) 3 only
(c) 1 and 2
(d) 2 and 3
Answer: (d)
Explanation:
Statement 1 is not correct:
A nanoparticle is a small particle that ranges between 1 to 100 nanometres in size. They could be generated by natural processes or could be made artificially and released into the environment.
