Nanofiber

Example of a cellulose nanofiber network.

Nanofibers are fibers with diameters in the nanometer range (typically, between 1 nm and 1 μm). Nanofibers can be generated from different polymers and hence have different physical properties and application potentials. Examples of natural polymers include collagen, cellulose, silk fibroin, keratin, gelatin and polysaccharides such as chitosan and alginate.[1][2] Examples of synthetic polymers include poly(lactic acid) (PLA), polycaprolactone (PCL),[3] polyurethane (PU), poly(lactic-co-glycolic acid) (PLGA), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and poly(ethylene-co-vinylacetate) (PEVA).[1][2] Polymer chains are connected via covalent bonds.[4] The diameters of nanofibers depend on the type of polymer used and the method of production.[5] All polymer nanofibers are unique for their large surface area-to-volume ratio, high porosity, appreciable mechanical strength, and flexibility in functionalization compared to their microfiber counterparts.[1][2][6]

There exist many different methods to make nanofibers, including drawing, electrospinning, self-assembly, template synthesis, and thermal-induced phase separation. Electrospinning is the most commonly used method to generate nanofibers because of the straightforward setup, the ability to mass-produce continuous nanofibers from various polymers, and the capability to generate ultrathin fibers with controllable diameters, compositions, and orientations.[6] This flexibility allows for controlling the shape and arrangement of the fibers so that different structures (i.e. hollow, flat and ribbon shaped) can be fabricated depending on intended application purposes.

Nanofibers have many possible technological and commercial applications. They are used in tissue engineering,[1][2][7] drug delivery,[8][9][10] seed coating material,[11][12][13] cancer diagnosis,[14][15][16] lithium-air battery,[17][18][19] optical sensors,[20][21][22] air filtration,[23][24][25] redox-flow batteries [26] and composite materials.[27]

  1. ^ a b c d Vasita R, Katti DS (2006). "Nanofibers and their applications in tissue engineering". International Journal of Nanomedicine. 1 (1): 15–30. doi:10.2147/nano.2006.1.1.15. PMC 2426767. PMID 17722259.
  2. ^ a b c d Khajavi R, Abbasipour M, Bahador A (2016). "Electrospun biodegradable nanofibers scaffolds for bone tissue engineering". J Appl Polym Sci. 133 (3): n/a. doi:10.1002/app.42883.
  3. ^ Sivan, Manikandan; Madheswaran, Divyabharathi; Valtera, Jan; Kostakova, Eva Kuzelova; Lukas, David (2022-01-01). "Alternating current electrospinning: The impacts of various high-voltage signal shapes and frequencies on the spinnability and productivity of polycaprolactone nanofibers". Materials & Design. 213: 110308. doi:10.1016/j.matdes.2021.110308. ISSN 0264-1275. S2CID 245075252.
  4. ^ Teraoka I (2002). Polymer Solutions: An Introduction to Physical Properties. John Wiley & Sons, Inc. ISBN 978-0-471-22451-8.
  5. ^ Reneker D, Chun I (1996). "Nanometre diameter fibres of polymer produced by electrospinning". Nanotechnology. 7 (3): 216–223. Bibcode:1996Nanot...7..216R. doi:10.1088/0957-4484/7/3/009. S2CID 4498522.
  6. ^ a b Li D, Xia Y (2004). "Electrospinning of nanofibers: reinventing the wheel?". Adv Mater. 16 (14): 1151–1170. Bibcode:2004AdM....16.1151L. doi:10.1002/adma.200400719. S2CID 137659394.
  7. ^ Cite error: The named reference Ma was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Sharifi was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Ahn was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Garg was invoked but never defined (see the help page).
  11. ^ Farias BV, Pirzada T, Mathew R, Sit TL, Opperman C, Khan SA (2019-12-16). "Electrospun Polymer Nanofibers as Seed Coatings for Crop Protection". ACS Sustainable Chemistry & Engineering. 7 (24): 19848–19856. doi:10.1021/acssuschemeng.9b05200. S2CID 209709462.
  12. ^ Xu T, Ma C, Aytac Z, Hu X, Ng KW, White JC, Demokritou P (2020-06-29). "Enhancing Agrichemical Delivery and Seedling Development with Biodegradable, Tunable, Biopolymer-Based Nanofiber Seed Coatings". ACS Sustainable Chemistry & Engineering. 8 (25): 9537–9548. doi:10.1021/acssuschemeng.0c02696. S2CID 219914870.
  13. ^ De Gregorio PR, Michavila G, Ricciardi Muller L, de Souza Borges C, Pomares MF, Saccol de Sá EL, et al. (2017-05-04). "Beneficial rhizobacteria immobilized in nanofibers for potential application as soybean seed bioinoculants". PLOS ONE. 12 (5): e0176930. Bibcode:2017PLoSO..1276930D. doi:10.1371/journal.pone.0176930. PMC 5417607. PMID 28472087.
  14. ^ Cite error: The named reference Chen was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Ke was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Cristofanilli was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference Zhang 3 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference Economist was invoked but never defined (see the help page).
  19. ^ Cite error: The named reference Yang 2 was invoked but never defined (see the help page).
  20. ^ Cite error: The named reference Wang was invoked but never defined (see the help page).
  21. ^ Cite error: The named reference Yang 3 was invoked but never defined (see the help page).
  22. ^ Cite error: The named reference Zubia was invoked but never defined (see the help page).
  23. ^ Cite error: The named reference Kelly was invoked but never defined (see the help page).
  24. ^ Cite error: The named reference Scholten was invoked but never defined (see the help page).
  25. ^ Cite error: The named reference Graham was invoked but never defined (see the help page).
  26. ^ "A bibliometric review of flow batteries' progress and challenges". Journal of Electrochemical Science and Engineering. 2022.
  27. ^ Maccaferri, Emanuele; Mazzocchetti, Laura; Benelli, Tiziana; Brugo, Tommaso Maria; Zucchelli, Andrea; Giorgini, Loris (2022-01-12). "Self-Assembled NBR/Nomex Nanofibers as Lightweight Rubbery Nonwovens for Hindering Delamination in Epoxy CFRPs". ACS Applied Materials & Interfaces. 14 (1): 1885–1899. doi:10.1021/acsami.1c17643. ISSN 1944-8244. PMC 8763375. PMID 34939406.