by What are Carbon Nanotubes?
They are cylindrical carbon molecules with a diameter close to a nanometer. They are the strongest and thinnest materials yet discovered and have an extraordinary array of useful properties. Nanotubes can be both conductors and semi-conductors, so they are very useful for designing computer chips, materials and more. Sometimes referred to as rolled-up graphene sheets, nanotubes come in multiple hybridizations including single-walled nanotubes (SWNTs) and multi-walled nanotubes (MWNTs). Nanotubes exhibit extraordinary strength and unique electrical properties and are efficient conductors of heat.
Properties
They have some remarkable properties that make them extremely attractive for multiple applications. T
hey are around 100 times stronger than steel at about 1/6th the weight. Single-walled Carbon Nanotubes have shown strength of up to 63 GPa and elastic modulus of around 1 TPa. Due to their hollow structure and atomic thickness, carbon nanotubes offer exceptionally low densities. Electrical resistance varies greatly with different nanotube structures: some behave as metals while others behave as semiconductors. They can efficiently conduct both heat and electricity. Theoretical studies show that CNTs are able to support current densities 1000 times greater than copper wires and copper remains one of the best current carrying materials available today.
Applications
With their extraordinary mechanical and electronic properties, they are primed to revolutionize many industries and applications. Some key areas where they can be applied include:
– Electronics – Nanotubes can be used to build nanoscale wires, transistors and circuit boards. They may replace silicon in future computer chips for faster processing capabilities.
– Batteries and capacitors – Nanotubes can store lithium ions and greatly improve energy density of batteries and capacitors. This offers potential for lightweight and more powerful energy storage.
– Composites – Mixing nanotubes into materials like polymers, metal and ceramics creates composites with remarkably enhanced mechanical, thermal and electrical properties.
– Biomedical applications – Functionalized nanotubes are being studied for cellular imaging, cancer diagnosis and targeted drug delivery applications.
– Filtration membranes – Ultrafine carbon nanotube membranes could efficiently filter viruses, proteins and other biomolecules. This has applications for water purification and kidney dialysis among others.
– Aerospace – Exceptional strength and light weight of carbon nanotube composites is ideal for aircraft and space structures, thermal protection systems and energy storage solutions.
Production and Challenges
Several techniques are available for carbon nanotube production but mass production remains a challenge. Leading methods include arc discharge, laser ablation and chemical vapor deposition (CVD). While arc discharge and laser ablation can yield high quality nanotubes, scalability is limited. On the other hand, CVD allows scalable production through pyrolysis of hydrocarbons but quality needs further improvement. Challenges also remain in controlling the arrangement and properties of nanotubes during synthesis. Post-processing methods are required to separate nanotubes by structure, purity and electronic properties. Another challenge is functionalizing bare nanotubes for different applications through surface modification without damaging their intrinsic properties. Overall, scaling up manufacturing while maintaining affordability is the key priority for industrial applications of them to take off.
They are truly remarkable materials with properties far exceeding existing materials. However, we are still at an early stage of commercializing their potential. Material quality, production scalability and functionality needs further advances through focused R&D efforts. Many promising applications require multi-functional carbon nanotube architectures, necessitating better control over nanotube growth orientation, alignment and assembly. As these challenges are addressed, they could quite literally change our world. They may transform electronics, power grids, transportation, structures, medical devices and more. With continued progress to make nanotubes readily available in large volumes, their use in innovative commercial applications seems destined to grow exponentially over the coming decades. In summary, carbon nanotubes hold tremendous promise as a revolutionary materials platform and foundational technology for the future.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it.
