Impact of the wet spinning parameters on the alpaca‐based polyacrylonitrile composite fibers: Morphology and enhanced mechanical properties study

2020 ◽  
Vol 137 (41) ◽  
pp. 49264 ◽  
Author(s):  
Md Abdullah Al Faruque ◽  
Rechana Remadevi ◽  
Joselito M. Razal ◽  
Maryam Naebe
Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 28 ◽  
Author(s):  
Ekaterina N. Maevskaia ◽  
Oksana P. Kirichuk ◽  
Sergei I. Kuznetzov ◽  
Elena N. Dresvyanina ◽  
Vladimir V. Yudin ◽  
...  

Composite chitosan fibers filled with chitin nanofibrils (CNF) were obtained by the wet spinning method. The paper discusses the mechanical properties of such type fibers and their hemocompatibility, as well as the possibility of optimizing these properties by adding chitin nanofibrils. It was shown that low CNF concentration (about 0.5%) leads to an increase in fiber tensile strength due to the additional orientation of chitosan macromolecules. At the same time, with an increase in the content of CNF, the stability of the mechanical properties of composite fibers in a humid medium increases. All chitosan fibers, except 0.5% CNF, showed good hemocompatibility, even on prolonged contact with human blood. The addition of chitin nanofibers leads to decrease in hemoglobin molecules sorption due to the decline in optical density at wavelengths of 414 nm and 540 nm. Nevertheless, the hemolysis of fibers was comparable or even lesser that carbon hemosorbent, which is actively used in clinical practice.


2007 ◽  
Vol 2 (4) ◽  
pp. 155892500700200 ◽  
Author(s):  
Jaewoong Lee ◽  
R. M. Broughton ◽  
S. D. Worley ◽  
T. S. Huang

Cellulose and m-aramid were dissolved in an ionic liquid, and dry-jet wet spinning was employed to prepare composite fibers which could be rendered antimicrobial through exposure to chlorine bleach. The small domains of the m-aramid allowed a much higher accessibility and degree of chlorination than has been reported even for 100% m-aramid fibers. The mechanical properties including denier, tenacity, and strain at break were evaluated. The chlorinated composite fiber inactivated both Gram-positive and Gram-negative bacteria. The antimicrobial activity was retained after repeated washing and recharging.


Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2797 ◽  
Author(s):  
Hamideh Mirbaha ◽  
Parviz Nourpanah ◽  
Paolo Scardi ◽  
Mirco D’incau ◽  
Gabriele Greco ◽  
...  

Wet spinning of polyacrylonitrile/carbon nanotubes (PAN/CNT) composite fibers was studied and the effect of spinning conditions on structure and properties of as-spun fibers influenced by the presence of CNTs investigated. Unlike PAN fibers, shear force had a larger effect on crystalline structure and physical and mechanical properties of PAN/CNT composite fibers compared to the elongational force inside a coagulation bath. Under shear force CNTs induced nucleation of new crystals, whereas under elongational force nucleation of new crystals were hindered but the already formed crystals grew bigger. To our knowledge, this key effect has not been reported elsewhere. At different shear rates, strength, Young’s modulus and strain at break of PAN/CNT as-spun fibers were improved up to 20% compared to PAN fibers. Application of jet stretch had less influence on physical and mechanical properties of PAN/CNT fibers compared to PAN fibers. However, the improvement of interphase between polymer chains and CNTs as a result of chain orientation may have contributed to enhancement of Young’s modulus of jet stretched composite fibers.


2010 ◽  
Vol 26-28 ◽  
pp. 104-107
Author(s):  
Hui Qin Zhang ◽  
Li Yan Zhang ◽  
Xiao Wei He

Concentrated sulfuric and concentrated nitric acids treated multi-walled carbon nanotubes (MWNTs) and polyacrylonitrile (PAN) were fabricated via a conventional wet spinning process. Mechanical properties of the composite fibers were studied by tensile testing and structures of the fibers were investigated via SEM and DMA. The results showed that the strength, storage modulus and glass translation temperature of the composite fiber containing 5% content of MWNTs were improved compared with those of pure PAN. The fiber with 5wt% MWNTs showed its conductivity of an order of 10-3S/cm.


2021 ◽  
Vol 13 (34) ◽  
pp. 40953-40963
Author(s):  
Chuang Wang ◽  
Yingzhan Li ◽  
Hou-Yong Yu ◽  
Somia Yassin Hussain Abdalkarim ◽  
Jinping Zhou ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1563
Author(s):  
Sofia Marquez-Bravo ◽  
Ingo Doench ◽  
Pamela Molina ◽  
Flor Estefany Bentley ◽  
Arnaud Kamdem Tamo ◽  
...  

Extremely high mechanical performance spun bionanocomposite fibers of chitosan (CHI), and cellulose nanofibers (CNFs) were successfully achieved by gel spinning of CHI aqueous viscous formulations filled with CNFs. The microstructural characterization of the fibers by X-ray diffraction revealed the crystallization of the CHI polymer chains into anhydrous chitosan allomorph. The spinning process combining acidic–basic–neutralization–stretching–drying steps allowed obtaining CHI/CNF composite fibers of high crystallinity, with enhanced effect at incorporating the CNFs. Chitosan crystallization seems to be promoted by the presence of cellulose nanofibers, serving as nucleation sites for the growing of CHI crystals. Moreover, the preferential orientation of both CNFs and CHI crystals along the spun fiber direction was revealed in the two-dimensional X-ray diffraction patterns. By increasing the CNF amount up to the optimum concentration of 0.4 wt % in the viscous CHI/CNF collodion, Young’s modulus of the spun fibers significantly increased up to 8 GPa. Similarly, the stress at break and the yield stress drastically increased from 115 to 163 MPa, and from 67 to 119 MPa, respectively, by adding only 0.4 wt % of CNFs into a collodion solution containing 4 wt % of chitosan. The toughness of the CHI-based fibers thereby increased from 5 to 9 MJ.m−3. For higher CNFs contents like 0.5 wt %, the high mechanical performance of the CHI/CNF composite fibers was still observed, but with a slight worsening of the mechanical parameters, which may be related to a minor disruption of the CHI matrix hydrogel network constituting the collodion and gel fiber, as precursor state for the dry fiber formation. Finally, the rheological behavior observed for the different CHI/CNF viscous collodions and the obtained structural, thermal and mechanical properties results revealed an optimum matrix/filler compatibility and interface when adding 0.4 wt % of nanofibrillated cellulose (CNF) into 4 wt % CHI formulations, yielding functional bionanocomposite fibers of outstanding mechanical properties.


2021 ◽  
Author(s):  
Yanhong Jin ◽  
Yuanyuan Jing ◽  
Wenxin Hu ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
...  

Abstract Lignin has been used as a sustainable and eco-friendly filler in composite fibers. However, lignin aggregation occurred at high lignin content, which significantly hindered the further enhancement of fiber performance. The incorporation of graphene oxide (GO) enhanced the mechanical properties of the lignin/poly(vinyl alcohol) (PVA) fibers and affected their structure. With the GO content increasing from 0 to 0.2%, the tensile strength of 5% lignin/PVA fibers increased from 491 MPa to 631 MPa, and Young's modulus increased from 5.91 GPa to 6.61 GPa. GO reinforced 30% lignin/PVA fibers also showed the same trend. The tensile strength increased from 455 MPa to 553 MPa, and Young's modulus increased from 5.39 GPa to 7 GPa. The best mechanical performance was observed in PVA fibers containing 5% lignin and 0.2% GO, which had an average tensile strength of 631 MPa and a Young’s modulus of 6.61 GPa. The toughness values of these fibers are between 9.9-15.6 J/g, and the fibrillar and ductile fracture microstructure were observed. Structure analysis of fibers showed that GO reinforced 5% lignin/PVA fibers had higher crystallinity, and evidence of hydrogen bonding among GO, lignin, and PVA in the gel fibers was revealed. Further, water resistance and swelling behavior of composite PVA fibers were studied to further evidence the structure change of composite fibers.


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