We proposed a new approach for producing nanofibers. It involves irradiating a fiber with radiation from a carbon dioxide (CO2) laser while drawing it at a supersonic velocity. A supersonic jet was generated by blowing air into a vacuum chamber through the orifice used to inject the fiber into the vacuum chamber. The adiabatic expansion of air across the orifice cools the jet. The fiber is instantly melted by the high-power laser beam that irradiates in the cold supersonic jet. It is then tremendously deformed by the shear force generated by the supersonic flow, and ultradrawn to a draw ratio of the order of 105. We named this preparation method CO2-laser supersonic drawing (CLSD). Supersonic drawing has already been applied to poly(L-lactic acid), Poly(ethylene terephthalate), and poly(ethylene-2,6-naphthalate). The nanofiber obtained by the CLSD is basically endless nanofiber because a fiber supplied at a constant speed was continuously laser-irradiated. The CLSD can easily prepare various nanofibers by only CO2 laser-irradiation without combining any process and using any solvent.
References
[1] Suzuki A, Aoki K. Euro Polym J 2008; 44: 2499-2505.
[2] Suzuki A, Tanizawa K. Poymer 2009; 50: 913-921.
[3] Suzuki A, Yamada Y. J Appl Polym Sci 2010; 116: 1913-1919.
[4] Suzuki A, Arino k. Poymer 2010; 51: 1830-1836.
[5] Suzuki A, Arino k. Euro Polym J 2012; 48: 1169-1176.
[6] Suzuki A, Hayashi H, eXPRESS Polymer Letters 2013; 7, 519?527
[7] Suzuki A, Mikuni T, Hasegawa T. J Appl Polym Sci 2014, 131, 40015.

Questionnaire 2014/Shinshu University Faculty of Textile Science and Technology Fii