Polyacrylonitrile-MV85000

Catalog	ACM25014419-10
CAS	25014-41-9
Structure
Molecular Weight	85000
Storage	Room temperature

Case Study

Manufacturing Carbon Nanofibers from Polyacrylonitrile Precursors

Nataraj, S. K., et al. Progress in polymer science, 2012, 37(3), 487-513.

Carbon nanofibers (CNFs) are long, thin materials with diameters of approximately 10-1000 nm that are attractive for use in electronics and energy storage applications. The preparation of CNFs from polyacrylonitrile (PAN) precursors involves three main stages; electrospinning, oxidative stabilization, and carbonization.
Proper stabilization of spun PAN fibers is crucial for achieving high-quality carbon nanofibers (CNFs). This stabilization process entails heating PAN fibers in an oxygen-rich environment, which promotes the cyclization of nitrile groups (C≡N) and facilitates the crosslinking of molecular chains, forming the structure -C=N-C=N-. This step is essential as it prevents the fibers from melting during the subsequent carbonization phase. In the following phase, the carbonization of the stabilized PAN fibers occurs in an inert atmosphere, allowing for the selective elimination of non-carbonized materials as gases, such as H2O, NH3, CO, HCN, CO2, and N2. As a result, the carbon fibers produced yield approximately 50-57% of the original PAN mass.
As shown in the figure, during the formation of carbonized structures from PAN, when fibers reach the stabilization temperature, a dense ladder-polymer structure begins to emerge above 200 °C due to reactions with oxygen, preventing melting in the carbonization process. Carbonization itself involves heating the stabilized PAN fibers between 700 and 1500 °C in an inert atmosphere to expel non-carbon elements in gaseous form. Following carbonization at 800 °C, denitrogenation occurs, leading to the formation of a network structure. Throughout this process, the fibers experience a reduction in diameter and lose nearly 50% of their weight.

Patterned Polyacrylonitrile Nanofiber Membranes for Air Filtration

Lou, Li-Hua, et al. Textile Research Journal, 2017, 87(2), 208-215.

Patterned membranes were prepared by utilizing the fluffy properties of polyacrylonitrile (PAN) as the electrospinning material and the raised bubble template as the collector. With this special structure, the pressure drop drops significantly from 151.7 mm H2O to 24.7 mm H2O, which can be used to remove particles around 75 nm.
PAN solution preparation and electrospinning
· The fabrication of nanofiber membranes was conducted using a mono-needle electrospinning apparatus. In this process, PAN powder (MW=75,000 g/mol) was dissolved in DMF (99.5%) to achieve a mass fraction of 14%.
· The resulting PAN solutions were stirred for approximately 8 hours until they reached uniformity, after which they were fed through a metal needle with an inner diameter of 0.5 mm at a controlled rate of 0.4 mL/h.
· A high voltage of 13 kV was applied to the needle tip containing the PAN solution, creating a continuous jet stream. The distance maintained between the spinning voltage and the collection device was 20 cm.
· The receiving templates used in this paper are aluminum foil, embossed paper and a bulged bubble, respectively. The relevant temperature and humidity were 25 2C and 45 2%, respectively.