Carbon Nanoflorets

Context:

IIT team finds carbon ‘flowers’ excelling at turning light to heat.

Key Details – Carbon nanoflorets:

• Synthesis –
  • Heated a special form of silicon dust (white in colour) called DFNS (for dendritic fibrous nanosilica) in a furnace.
  • Introduction of acetylene gas into the chamber.
  • White powder turned black (a sign that carbon had been deposited on the DFNS)
  • Black powder is treated with a strong chemical that dissolved the DFNS away, leaving carbon particles behind.
• Resultant –
  • Spherical nanostructures like tiny marigold flowers, made only of carbon.
  • They called the material carbon nanoflorets.
• Feature –
  • Solar-thermal conversion: Nanoflorets converted the light energy they absorbed into thermal energy with a remarkable efficiency of 87%
  • Adhesion is nearly as good as paint on a wall
• 2 different techniques –
  • Formaldehyde-phenol polymerisation
  • Chemical Vapour Deposition (CVD)
  • They differed in the method used to deposit carbon on the DFNS template and it didn’t affect the characteristics of the product.
• 3 properties –
  • Absorbs 3 frequencies in sunlight – infrared, visible light, and ultraviolet. (while others absorb only visible and ultraviolet light)
  • Carbon cones structure – More internal reflection of light
  • More distance between each structures
• Applications –
  • Good material to heat other materials (e.g. water heated using solar energy)
    • 1 m sq. coating of carbon nanoflorets on a surface could vaporise 5 litres of water in an hour
  • Help heat up housing and sterilise surfaces in hospitals with reducing the carbon footprint
  • Can be coated on paper, metal, and terracotta clay

Source: The Hindu

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Previous Year Question

With reference to carbon nanotubes, consider the following statements:
1. They can be used as carriers of drugs and antigens in the human body.
2. They can be made into artificial blood capillaries for an injured part of the human body.
3. They can be used in biochemical sensors.
4. Carbon nanotubes are biodegradable.
Which of the statements given above are correct?
(a) 1 and 2 only
(b) 2, 3 and 4 only
(c) 1, 3 and 4 only
(d) 1, 2, 3 and 4

Answer: (d)

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