49. Polyacrylonitrile-Lignin Blend

Carbon nanofibers (CNFs) are highly sought owing to their exceptional mechanical strength, multifunctional properties, and lightweight nature, making them ideal for applications in electronics, transportation, and aerospace. Their high strength-to-weight ratio contributes to lightweight, durable composite materials. Most carbon nanofibers are currently produced from nonrenewable resources like polyacrylonitrile, leading to adverse effects in the environment associated with higher-cost production rate. In spite of this, lignin can be used as an alternative material for the production of carbon nanofibers since it is an inexpensive, biodegradable, abundantly available and renewable resource from biomass resources. Lignin-based CNFs which have undergone rapid development in the past two decades are made from lignin-based carbon fibers. A CNF made from a polyacrylonitrile (PAN)/lignin blend will be discussed in this book chapter. Various spinning technologies are employed to manufacture lignin-based CNFs such as wet spinning, melt spinning, dry spinning, and electrospinning. This chapter also addresses issues like viscosity, low density, and inappropriate molecular orientation in lignin-based CNFs, providing a comprehensive overview of reinforcement strategies entailed to enhance these characteristics. Furthermore, it explores the most common uses of CNFs in electrical devices, including supercapacitors, sodium-ion batteries, and lithium-ion batteries. Finally, the discussion revolves on prospective advances in the production and performance of lignin-based carbon nanofibers, emphasizing their future significance in high-performance energy storage and several other applications.