َArticles are OPEN Access and publication is free of charge

Document Type : Original Article


1 Department of Textile Engineering, Isfahan University of Technology, Isfahan, Iran.

2 Textile Engineering Department, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.

3 Fabric Design Department, Faculty of Applied Arts, University of Art, Tehran, Iran.


The present study attempts to combine the properties
of natural and synthetic fibers by using nanotechnology.
Considering the potential of nylon nanofiber structures in some
applications such as controlled drug release, moisture microsensors
and antibacterial filters, the moisture absorption of the
nanofibers could be improved via using biocompatible natural
fibers such as wool. In this investigation, it was achieved to
produce yarns of composite nylon 6 nanofibers, incorporating
wool nanoparticles (WNPs), via electrospinning. WNPs were
added to the electrospinning solution of nylon 6 in various
concentrations. Scanning electron microscopy was employed
to characterize the morphology of composite nanofibers.
The existence of WNPs in the nanofibers was confirmed by
transmission electron microscopy. Fourier transform infrared
spectroscopy (FTIR) spectra showed that nanofibrous
composite formation did not influence the chemical bonds of
both the wool nanoparticles and nylon 6, and no new steady
bonds were formed. It was found that an increase in the
WNPs concentration increased the diameter of composite
nanofibers from 152±16 nm (pure nanofibers) to 266±51 nm
(7 wt% nanoparticles). The assessment of moisture regain
of composite nanofiber yarns showed that the moisture
absorption of nylon 6 nanofibers improved by introducing the
WNPs as hydrophilic components. The moisture regain of the composite nanofibers yarn containing 7 wt% nanoparticles
was found to be higher than that of the pure nanofibers yarn
by about 117.1%. On the other hand, tensile strength and
elongation-at-break of composite nanofiber yarns initially
decreased and then increased with the increase in WNPs


[1] J.G. Rouse and M.E. Van Dyke, “A review of keratin-based biomaterials for biomedical applications”, Materials, vol. 3, no. 2, pp. 999-1014, 2010.
[2] Z. Chunhua, X. Liangjun, Z. Jiajing, L. Xin, and W. Xu, “Utilization of waste wool fi bers for fabrication of wool powders and keratin: a review”, J. Leather Sci. Eng., vol. 2, no. 1, pp. 1-15, 2020.
[3] S. Sukigara, M. Gandhi, J. Autesde, M. Micklus, and F. Ko, “Regeneration of Bombyx mori silk by electrospinning-part 1: processing parameters and geometric properties”, Polymer, vol. 44, no. 19, pp. 5721-5727, 2003.
[4] J.Y. Hu, Y. Li, Y.F. Chang, K.W. Yeung, and C.W. Yuen, “Transport properties of fabrics treated with nano-wool fi brous materials”, Colloids Surface. Physicochem. Eng. Asp., vol. 300, no. 1-2, pp. 136-139, 2007.
[5] Y.S. Cheng, A. Hassan, M.I H. Ghazali, and A.F. Ismail, “Heat sealability of laminated fi lms with LLDPE and LDPE as the sealant materials in bar sealing application”, J. Appl. Polym. Sci., vol. 104, no. 6, pp. 803-808, 2007.
[6] W. Xu, X. Wang, W. Li, X. Peng, X. Liu, and X.G. Wang, “Characterization of superfi ne wool powder/poly(propylene) blend fi lm”, Macromol. Mater. Eng., vol. 292, no. 5, pp. 674-680, 2007.
[7] S. Novak, S. Kobe, and P. McGuinessz, “The effect of chemically bonded organic surface layers on the behavior of fi ne powders”, Powder. Technol., vol. 139, no. 2, pp. 140-147, 2004.
[8] W. Xu, W. Cui, W. Li, and W. Guo, “Development and characterizations of super-fi ne wool powder”, Powder. Technol., vol. 140, no. 1, pp. 136-140, 2004.
[9] K. Patil, R. Rajkhowa, X. Wang, and T. Lin, “Review on fabrication and applications of ultrafi ne particles from animal protein fi bers”, Fiber Polym., vol. 15, pp. 187-194, 2014.
[10] G. Wen, J.A. Rippon, P.R. Brady, X.G. Wang, X. Liu, and P.G. Cookson, “The characterization and chemical reactivity of powdered wool”, Powder. Technol., vol. 193, no. 2, pp. 200-207, 2009.
[11] A. Kantouch, O. Allam, L. EI-Gabry, and H.E. Sayed, “Effect of pretreatment of wool fabric with keratin on its dyeability with acid and reactive dyes”, Indian J. Fibre Text. Res., vol. 37, no. 2, pp. 157-161, 2011.
[12] G. Ke and W. Xu, “Preparation and properties of superfi ne wool powder/chitosan complex membrane”, J. Text. Inst., vol. 103, no. 11, pp. 1183-1188, 2012.
[13] W. Li, G. Ke, G. Li, and W. Xu, “Study on the structure and properties of viscose/wool powder blended fi ber”, Fiber. Text. East. Eur., vol. 23, no. 1, pp. 26-29, 2015.
[14] X. Wang, W. Xu, W. Cui, W. Li, and X. Wang, “Bleaching and dyeing of superfi ne wool powder/polypropylene blend fi lm”, Res. J. Text. Appar, vol. 12, no. 4, pp. 12-20, 2008.
[15] P.S. Bhavsar, M. Zoccola, A. Patrucco, A. Montarsolo, R. Mossotti, M. Giansetti, G. Rovero, S.S. Maier, A. Muresan, and C. Tonin, “Superheated water hydrolyzed keratin: a new application as a foaming agent in foam dyeing of cotton and wool fabrics”, ACS Sustain Chem. Eng., vol. 5, no. 10, pp. 9150-9159, 2017.
[16] W. Xu, J. Fang, W. Cui, and J. Huang, “Modifi cation of polyurethane by superfi ne protein powder”, Polym. Eng. Sci., vol. 46, no. 5, pp. 617-622, 2006. [17] H. Chang, Q. Li, C. Xu, R. Li, H. Wang, Z. Bu, and T. Lin, “Wool powder: an effi cient additive to improve mechanical and thermal properties of poly(propylene carbonate)”, Compos. Sci. Technol., vol. 153, pp. 119-127, 2017.
[18] J.R. Barone, W.F. Schmidt, and C.F.E. Liebner, “Thermally processed keratin fi lms”, J. Appl. Polym. Sci., vol. 97, no. 4, pp. 1644-1651, 2005.
[19] K. Yamauchi, H. Hojo, Y. Yamamoto, and T. Tanabe, “Enhanced cell adhesion on RGDS-carrying keratin fi lm”, Mater. Sci. Eng., vol. 23, no. 4, pp. 467-472, 2003.
[20] R.K. Donato and A. Mija, “Keratin associations with synthetic, biosynthetic and natural polymers: an extensive review”, Polymers, vol. 12, no. 1, pp. 32-40, 2019.
[21] R. Karthikeyan, S. Balaji, and P.K. Sehgal, “Industrial applications of keratins-a review”, J. Sci. Ind. Res., vol. 66, no. 9, pp. 710-715, 2007.
[22] A. Aluigi, G. Sotgiu, A. Torreggiani, A. Guerrini, V.T. Orlandi, F. Corticelli, and G. Varchi, “Methylene blue doped fi lms of wool keratin with antimicrobial photodynamic activity”, ACS Appl. Mater. Interf., vol. 7, no. 31, pp. 17416-17424, 2015.
[23] X. Zhong, R. Li, Z. Wang, W. Wang, and D. Yu, “Eco-fabrication of the antibacterial nanofi brous membrane with high moisture permeability from wasted wool fabrics”, Waste Manag., vol. 102, pp. 404-411, 2020.
[24] Y. Ozaki, Y. Takagi, H. Mori, and M. Hara, “Porous hydrogel of wool keratin prepared by a novel method: an extraction with a guanidine/2-mercaptoethanol solution followed by a dialysis”, Mater. Sci. Eng. C Mater. Biol. Appl., vol. 42, pp. 146-154, 2014.
[25] C. Ferroni, G. Sotgiu, A. Sagnella, G. Varchi, A. Guerrini, D. Giuri, E. Polo, V.T. Orlandi, E. Marras, M. Gariboldi, E. Monti, and A. Aluigi, “Wool keratin 3D scaffolds with light-triggered antimicrobial activity”, Biomacromolecules, vol. 17, no. 9, pp. 2882-2890, 2016.
[26] H. Zhu, R. Li, X. Wu, K. Chen, and J. Che, “Controllable fabrication and characterization of hydrophilic PCL/wool keratin nanonets by electronetting”, Eur. Polym. J., vol. 86, no. 3, pp. 154-161, 2017.
[27] Y. Li, Y. Wang, J. Ye, J. Yuan, and Y. Xiao, “Fabrication of poly(ε-caprolactone)/keratin nanofi brous mats as a potential scaffold for vascular tissue engineering”, Mater. Sci. Eng. C., vol. 68, pp. 177-183, 2016.
[28] X. Zhang and X. Chen, “Research article: preparation of polyamide 6/CeO2 Composite nanofi bers through electrospinning for biomedical applications”, Int. J. Polym. Sci., vol. 2019, pp. 1-8, 2019.
[29] B. Shen, D. Zhang, Y. Wei, Z. Zhao, X. Ma, X. Zhao, S. Wang, and W. Yang, “Preparation of Ag doped keratin/PA6 nanofi ber membrane with enhanced air fi ltration and antimicrobial properties”, Polymers, vol. 11, no. 9, pp. 1511-1521, 2019.
[30] L. Francis, F. Giunco, A. Balakrishnan, and E. Marsanoa, “Synthesis, characterization and mechanical properties of nylon–silver composite nanofi bers prepared by electrospinning”, Curr. Appl. Phys., vol. 10, no. 4, pp. 1005-1008, 2010.
[31] R. Nirmala, J.W. Jeong, R. Navamathavan, and H.Y. Kim, “Synthesis and electrical properties of TiO2 nanoparticles embedded in polyamide-6 nanofi bers via electrospinning”, Nano-Micro Lett., vol. 3, pp. 56-61, 2011.
[32] A. Aghakhani, E. Kazemi, and M. Kazemzad, “Preparation of a novel KCC-1/nylon 6 nanocomposite via electrospinning technique”, J. Nanopart. Res., vol. 17, no. 10, pp. 386-390, 2015.
[33] H.R. Pant and C.S. Kima, “Electrospun gelatin/nylon-6 composite nanofi bers for biomedical applications”, Polym. Int., vol. 62, no. 7, pp. 1008-1013, 2013.
[34] G. Panthi, N.A.M. Barakat, P. Risal, A. Yousef, B. Pant, A.R. Unnithan, and H.Y. Kim, “Preparation and characterization of nylon-6/gelatin composite nanofi bers via electrospinning for biomedical applications”, Fiber. Polym., vol. 14, pp. 718-723, 2013.
[35] K. Koosha, S. Habibi, and A. Talebian, “Microstructural study of nylon-6/gelatin composite nanofi bers”, Russ. J. Appl. Chem., vol. 90, pp. 1640-1647, 2017.
[36] K. Nasouria and P. Valipour, “Fabrication of polyamide 6/carbon nanotubes composite electrospun nanofi bers for microwave absorption application”, Polym. Sci., Ser. A, vol. 57, no. 3, pp. 359-364, 2015.
[37] M.V. Jose, B.W. Steinert, V. Thomas, D.R. Dean, M.A. Abdalla, G. Price, and G.M. Janowski, “Morphology and mechanical properties of nylon 6/MWNT nanofi bers”, Polymer, vol. 48, no. 4, pp. 1096-1104, 2007.
[38] X.L. Xie, Y.W. Mai, and X.P. Zhou, “Dispersion and alignment of carbon nanotubes in polymer matrix: a review”, Mater. Sci. Eng. R, vol. 49, pp. 89-112, 2005.
[39] Y. Guo, G. Xu, X. Yang, K. Ruan, T. Ma, Q. Zhang, J. Gu, Y. Wu, H. Liu, and Z. Guo, “Signifi cantly enhanced and precisely modeled thermal conductivity in polyimide nanocomposites with chemically modifi ed graphene via in situ polymerization and electrospinning-hot press technology”, J. Mater. Chem. C., vol. 6, no. 12, pp. 3004-3015, 2018.
[40] M. Toriello, M. Afsari, H.S. Kyong, and L.D. Tijing,“Review progress on the fabrication and application of electrospun nanofi ber composites”, Membranes, vol. 10, no. 9, pp. 204-211, 2020.
[41] S. Ramakrishna, K. Fujihara, W.E. Teo, T.C. Lim, and Z. Ma, An Introduction to Electrospinning and Nanofibers, World Sci. Singapore, 2005, pp. 194-205.
[42] S.D. Liu, D. Li, Y. Yang, and L. Jiang, “Fabrication, mechanical properties and failure mechanism of random and aligned nanofi ber membrane with different parameters”, Nanotechnol. Rev., vol. 8, pp. 218-226, 2019.
[43] M.B. Bazbouz and G.K. Stylios, “Alignment and optimization of nylon 6 nanofi bers by electrospinning”, J. Appl. Polym. Sci., vol. 107, no. 5, pp. 3023-3032, 2008.
[44] C. Mit-Uppatham, M. Nithitanakul, and P. Supaphol, “Ultrafi ne electrospun polyamide-6 fi bers: effect of solution conditions on morphology and average fi ber diameter”, Macromol. Chem. Phys., vol. 205, no. 17, pp. 2327-2338, 2004.
[45] D. Esrafi lzadeh, R. Jalili, and M. Morshed, “Crystalline order and mechanical properties of
as-electrospun and post-treated bundles of uniaxially aligned polyacrylonitrile nanofi ber”, J. Appl. Polym. Sci., vol. 110, pp. 3014-3022, 2008.
[46] Y. Wu, L. Wang, B. Guo, and P.X. Ma, “Interwoven aligned conductive nanofi ber yarn/hydrogel composite scaffolds for engineered 3D cardiac anisotropy”, ACS Nano, vol. 11, no. 6, pp. 5646-5659, 2017.
[47] T. Yan, Z. Wang, Y.Q. Wang, and Z.J. Pan, “Carbon/graphene composite nanofi ber yarns for highly sensitive strain sensors”, Mater. Des., vol. 143, no. 19, pp. 214-223, 2018.
[48] X. Guan, G. Zheng, K. Dai, C. Liu, X. Yan, C. Shen, and Z. Guo, “Carbon nanotubes-adsorbed electrospun PA66 nanofi ber bundles with improved conductivity and robust flexibility”, ACS Appl. Mater. Interf., vol. 8, no. 22, pp. 14150-14159, 2016.
[49] Y. Zhou, J. He, H. Wang, K. Qi, N. Nan, X. You, W. Shao, L. Wang, B. Ding, and S. Cui, “Highly sensitive, self-powered and wearable electronic skin based on pressure-sensitive nanofi ber woven fabric sensor”, Sci. Rep., vol. 7, pp. 1-9, 2017.
[50] H. Pan, L. Li, L. Hu, and X. Cui, “Continuous aligned polymer fi bers produced by a modifi ed electrospinning method”, Polymer, vol. 47, no. 14, pp. 4901-4904, 2006.
[51] J. Li, L. Tian, N. Pan, and Z.J. Pan, “Mechanical and electrical properties of the PA6/SWNTs nanofi ber yarn by electrospinning”, Polym. Eng. Sci., vol. 54, no. 7, pp. 1618-1624, 2014.
[52] U. Ali, Y. Zhou, X. Wang, and T. Lin, “Direct electrospinning of highly twisted, continuous nanofi ber yarns”, J. Text. Inst, vol. 103, no. 1, pp. 80-90, 2012.
[53] J. He, K. Qi, L.D. Wang, Y. Zhou, R. Liu, and S. Cui, “Combined application of multi-nozzle air-jet electrospinning and airflow twisting for the effi cient preparation of continuous twisted nanofi ber yarn”, Fiber. Polym., vol. 16, pp. 1319-1326, 2015.
[54] N. Li, Q. Hui, H. Xue, and J. Xiong, “Electrospun polyacrylonitrile nanofi ber yarn prepared by funnel-shape collector”, Mater Lett., vol. 79, pp. 245-247, 2012.
[55] F. Hajiani, A.A.A. Jeddi, and A.A. Gharehaghaji, “An Investigation on the effects of twist on geometry of the electrospinning triangle and polyamide 66 nanofi ber yarn strength”, Fiber. Polym., vol. 13, pp. 244-252, 2012.
[56] M.B. Bazbouz and G.K. Stylios, “Novel mechanism for spinning continuous twisted composite nanofi ber yarns”, Eur. Polym. J., vol. 44, no. , pp. 1-12, 2008.
[57] W.C. Wang, Y.T. Cheng, and B. Estroff, “Electrostatic self-assembly of composite nanofi ber yarn”, Polymers, vol. 13, no. 1, pp. 12-21, 2021.
[58] W. Xu, J. Fang, W. Cui, and J. Huang, “Modifi cation of polyurethane by superfi ne protein powder”, Polym. Eng. Sci., vol. 46, no. 5, pp. 617-622, 2006.
[59] S.Y. Tsou, H.S. Lin, P.J. Cheng, C.L. Huang, J.Y. Wu, and C. Wang, “Rheological aspect on electrospinning of polyamide 6 solutions”, Eur. Polym. J., vol. 49, no. 11, pp. 3619-3629, 2013.
[60] M.I. Kohan, Nylon Plastic Handbook, Hanser: Munich, 1995, pp. 146-149.
[61] American Society for Testing and Materials (ASTM), Annual Book of ASTM Standards. Standard Test Method D584, Wool Content of Raw Wool-Laboratory Scale, Philadelphia (PA): ASTM, vol. 07.01, sec. 7, pp. 193-197, 1990.
[62] C. Gaidau, D.G. Epure, C.E. Enascuta, C. Carsote, C. Sendrea, N. Proietti, W. Chen, and H. Gu, “Wool keratin total solubilisation for recovery and reintegration -an ecological approach”, J. Clean. Prod., vol. 236, pp. 1-12, 2019.
[63] S. Jiang, Y. Chen, G. Duan, C. Mei, A. Greiner, and S. Agarwal, “Electrospun nanofi ber reinforced composites: a review”, Polym. Chem., vol. 9, no. 20, pp. 2685-2720, 2018.
[64] Z. Jiang, J. Yuan, P. Wang, X. Fan, J. Xu, Q. Wang, and L. Zhang, “Dissolution and regeneration of wool keratin in the deep eutectic solvent of choline chloride-urea”, Int. J. Biol. Macromol., vol. 119, pp. 423-430, 2018.
[65] K. Fujihara, M. Kotaki, and S. Ramakrishna, “Guided bone regeneration membrane made of polycaprolactone/calcium carbonate composite nano-fi bers”, Biomaterials, vol. 26, pp. 4139-4147, 2005.
[66] D. Cho, A.N. Netravali, and Y.L. Joo, “Mechanical properties and biodegradability of electrospun soy protein Isolate/PVA hybrid nanofi bers”, Polym. Degrad. Stab., vol. 97, no. 5, pp. 747–754, 2012.
[67] M. He, B. Zhang, Y. Dou, G. Yin, Y. Cuiac, and X. Chen, “Fabrication and characterization of electrospun feather keratin/poly(vinyl alcohol) composite nanofi bers”, RSC Adv., vol. 7, no. 16, pp. 9854-9861, 2017.
[68] H. Dou, K.B. Kung, Y.Y. Li, W. Fan, Y. Shen, H.Y. Liu, and J.H. He, “Effect of solution concentrations on the structure and properties of nanofi brous yarns by blown bubble-spinning”, Therm. Sci., vol. 25, no. 3B, pp. 2155-2160, 2021.
[69] N. Ghane, S. Mazinani, and A.A. Gharehaghaji, “Fabrication and characterization of hollow nanofi brous PA6 yarn reinforced with CNTs”, J. Polym. Res., vol. 25, no. 80, pp. 1-12, 2018.
[70] J. Huang, X. Liu, W. Li, and W. Xu, “Preparation and characterization of polypropylene/superfi ne down powder blend fi lms”, J. Thermoplast. Compos. Mater., vol. 25, no. 1, pp. 75-88, 2011.
[71] W. Xu, J. Fang, W. Cui, and J. Huang, “Modifi cation of polyurethane by superfi ne protein powder”, Polym. Eng. Sci., vol. 45, no. 5, pp. 617-622. 2006.
[72] W. Li, G. Ke, G. Li, and W. Xu, “Study on the structure and properties of viscose/wool powder blended fi ber”, Fiber. Text. East. Eur., vol. 1, no. 109, pp. 26-29, 2015.
[73] M. Zoccola, A. Montarsolo, A. Aluigi, A. Varesano, C. Vineis, and C. Tonin, “Electrospinning of polyamide 6/modifi ed-keratin blends”, E-Polymers, vol. 7, no. 1, pp. 1-19, 2007.
[74] Z. Moghbelnejad, A.A. Gharehaghaji, M. Yousefzadeh, and F. Hajiani, “Investigation of wicking phenomenon and tensile in three-layer composite nanofi brous
PA/PLLA yarn”, Polym. Eng. Sci., vol. 61, no. 2, pp. 576-585, 2020.
[75] P. Chegoonian, S.A. Hosseini Ravandi, M. Feiz, and S. Mallakpour, “Preparation of hydrophilic dimethyl 5-sodium sulfoisophthalate/poly(ethylene terephthalate) nanofi ber composite membranes for improving antifouling properties”, J. Appl. Polym. Sci., vol. 134, no. 8, pp. 1-8, 2017.