Context: Researchers at IIT-Madras have successfully extracted silicon carbide from (simulated) moon soil — a development that could lead to the making of silicon carbide-based composites for building lunar habitats.
Relevance of the Topic:Prelims: Key facts about Lunar composition and resource potential.
Major Highlights of the Research:
- The researchers combined the highland regolith simulant and with methane at high temperature to produce Silicon Carbide (SiC).
- Silicon Carbide is a combination of silicon and carbon. SiC can be utilised to make composites for building habitats on the moon.
- More research is needed to produce larger quantities of silicon carbide from lunar regolith.
- In the International Space Station, the Sabatier process is used to convert the carbon dioxide exhaled by the astronauts into methane and water by adding hydrogen from electrolysers.
Composition of the Lunar Soil
- Lunar regolith contains various elements. These elements are found in the form of oxides, silicates, and other minerals.
- Major elements- Oxygen (41-45%), Silicon, Aluminum, Calcium, Iron, Magnesium and Titanium.
- Minor elements- Manganese, Sodium, Potassium and Phosphorus.
- Lunar soil lacks organic matter, such as microbes or insects. Organic matter are the chemical compounds containing carbon-hydrogen bonds which are fundamental to life.
- The moon has two distinct terrains — the plains known as maria (dark spots found on the near side of the moon), and the highlands. Highlands are rich in silicon, aluminium and calcium.
What is Silicon Carbide?
- Silicon Carbide is a compound made from silicon and carbon. Naturally, SiC occurs in small amounts in meteorites and kimberlite (igneous rock). Most commercial silicon carbide is synthetic.
Properties of Silicon Carbide
- Light weight than steel and copper.
- High thermal conductivity of about three times that of stainless steel.
- Low thermal expansion and high force-to-weight radius.
- Excellent corrosion resistance as SiC is resistant to most chemical environments.
- High temperature stability and can withstand temperatures up to 1600°C, making it an ideal material for use in nuclear reactors.
- SiC is one of the hardest known substances; it competes closely with diamond and boron carbide.
Applications of Silicon Carbide
- Silicon carbide becomes a semiconductor after doping (addition of dopants like Boron, Nitrogen etc.)
- SiC transistors (MOSFETs) are used in powering electric vehicles. It improves efficiency and range of electric vehicles.
- SiC diodes are used in high-efficiency power conversion systems.
- Used as a substrate material in the production of light-emitting diodes (LEDs).
- Commonly used as an abrasive (because of its hardness). Used in manufacturing grinding wheels, cutting tools, and sandpaper.
- Widely used material for the use of structural ceramics.
- Manufacturing of bulletproof armor and aerospace components.
- Used as fuel and deoxidiser in steel manufacturing. It is cheaper and environmentally friendly.
- Ideal material for nuclear applications such as fuel particles and cladding.
- Used in the production of ultra-lightweight telescope mirrors.
- Alternative to diamonds in the jewelry industry.