Scientists have discovered the oldest known human-made nano-materials in the “unique black coatings” of ancient pottery shards dated to 600 BC that were unearthed from an archeological site in Keeladi, Tamil Nadu. The research was published in the journal Scientific Reports and the findings have been documented in a paper published in “Nature”.
- In accordance with the research these coatings are made of carbon nanotubes (CNTs) which have enabled the layer to last more than 2600 years.
- It should be noted that this discovery has succeeded the old known carbon nanostructure that was found in the Damascus blades from the 16th-18th century. Notably the technique used in the Damascus blades was also made in India.
- Before Damascus blade discovery, the gold and silver nanoparticles were found in Islamic pottery from the 7th-8th century CE (Common Era) and in the Roman Lycurgus Cup from the 4th century CE.
About Unique Black Coating:
The Unique black coatings observed in the inner wall of pottery shreds was analysed by the scientists through Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy.
- The analysis revealed the presence of single, multi-walled carbon nanotubes and layered sheets in the coating.
- The average diameter of single-walled carbon nanotube found to be about 6 ± 0.05 nm (nanometer) which is lowest among the single-walled carbon nanotubes reported from artefacts so far.
- The coating might include some vegetal fluid or extract which may have led to the formation of CNTs during high-temperature processing i.e. nearly 1100-1400 degree Celsius.
What are carbon nanotubes (CNTs)?
CNTs are tubular structures of carbon atoms arranged in an ordered manner through high-temperature processing. They have superlative properties, including high thermal and electrical conductivity, and very high mechanical strength.
Why is this discovery is important?
The coatings in ancient artifacts may not usually last this long due to wear and tear caused by changing conditions. But this newly discovered unique coating helped the layer to sustain more than 2600 years which states that the nano structures are already present in nature from way back.
Authors of the paper:
Manivannan Kokarneswaran, Prakash Selvaraj, Thennarasan Ashokan, Suresh Perumal, Pathikumar Sellappan, Kandhasamy Durai Murugan, Sivanantham Ramalingam, Nagaboopathy Mohan & Vijayanand Chandrasekaran
About Tamil Nadu:
Chief Minister (CM)– Edappadi Karuppa Palaniswami
Governor– Banwarilal Purohit