scholarly journals Hemocompatible Chitin-Chitosan Composite Fibers

Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 28 ◽  
Author(s):  
Ekaterina N. Maevskaia ◽  
Oksana P. Kirichuk ◽  
Sergei I. Kuznetzov ◽  
Elena N. Dresvyanina ◽  
Vladimir V. Yudin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Clinical Practice ◽  
Optical Density ◽  
Human Blood ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Prolonged Contact ◽  
The Stability ◽  
Chitosan Composite

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.

scholarly journals Regulation Mechanism of Graphene Oxide on the Structure and Mechanical Properties of Bio-Based Gel-Spun Lignin/Poly (Vinyl Alcohol) Fibers

2021 ◽  
Author(s):  
Yanhong Jin ◽  
Yuanyuan Jing ◽  
Wenxin Hu ◽  
Jiaxian Lin ◽  
Yu Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Young’S Modulus ◽  
Vinyl Alcohol ◽  
Young's Modulus ◽  
Lignin Content ◽  
Poly Vinyl Alcohol ◽  
Regulation Mechanism ◽  
Composite Fibers

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.

scholarly journals Study of Mechanical Behavior and Microstructure for Low-Hardness P92 Steel

2021 ◽  
Vol 2101 (1) ◽  
pp. 012074
Author(s):  
Weixin Yu ◽  
Zhen Dai ◽  
Jifeng Zhao ◽  
Lulu Fang ◽  
Yiwen Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Maximum Size ◽  
Rapid Decrease ◽  
Laves Phases ◽  
P92 Steel ◽  
A Chain ◽  
The Stability ◽  
Evolution Of Microstructure

Abstract The strength of P92 steel (tensile strength, specified plastic elongation strength) will decrease after its hardness is reduced, ferrite and carbides forming the structure. Carbides of grain size 5-6 are precipitated in the grains and grain boundaries. The martensite lath shape has completely disappeared. M23C6 carbide coarsened obviously, with a maximum size of about 500nm; The Laves phase is also aggregated and coarsened, connecting in a chain shape with a maximum size of more than 500nm. Evolution of microstructure, namely the obvious coarsening of M23C6 carbides and the aggregation and connection of Laves phases in a chain shape, are the main causes for rapid decrease in the stability of the material substructure and evident decline in mechanical properties and hardness. In addition, the MX phase did not change significantly, hardly affecting the hardness reduction of P92 steel.

Advances in measuring mechanical properties of soil in relation to soil health

2021 ◽  
pp. 215-240
Author(s):  
Muhammad Naveed ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Soil Health ◽  
Indentation Test ◽  
Mechanical Tests ◽  
Confined Compression ◽  
Microstructural Stability ◽  
Rigorous Testing ◽  
The Stability ◽  
Properties Of Soil

Although mechanical properties of soil are fast and easy to measure, they have not been used as indicators of soil health apart from cone penetration resistance. The confined compression test is traditionally used for the prediction of soil compaction risks. Other mechanical tests such as soil rheometry, miniature indentation test, and tensile strength are used for assessing the impact of certain amendments on the stability of the soil. Rheological techniques are appropriate to investigate microstructural stability of soil on a particle-particle scale. Miniature indentation test is very useful to perform when mechanical properties of soil are required to measure at the mm scale. Measurement of the tensile strength of soil has an advantage as it eliminates the effect of water content. There is clearly a need for more practical and rigorous testing on comparing different mechanical properties of the soil to test how they perform relative to each other.

Microstructure and Mechanical Behavior of CaCu3Ti4O12 Ceramics Hollow Fiber Prepared via Dry/Wet Spinning Method

2020 ◽  
Vol 1010 ◽  
pp. 239-243
Author(s):  
Mohsen Ahmadipour ◽  
Tunmise Ayode Otitoju ◽  
Mohammad Arjmand ◽  
Zainal Arifin Ahmad ◽  
Swee Yong Pung
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Hollow Fiber ◽  
Outer Layer ◽  
Pore Diameter ◽  
Hollow Fibers ◽  
Wet Spinning ◽  
Outer Diameter ◽  
Average Pore ◽  
Elongation At Break

Dry/wet method was used to prepare CaCuTi4O12 (CCTO) hollow fibers (HFs) and then the structural and physico-mechanical properties of HFs were characterized by XRD, FESEM, BET and tensile strength, respectively. The outer diameter and thickness of CCTO HFs were found to be 650 μm and 390 μm, respectively. A finger-like macrovoids and sponge-like was observed inside the membrane with a denser structure in the outer layer. It was observed that the crystallite size was increased from 28.5 nm to 37.0 nm while the average pore diameter was decreased from 34.65 nm to 29.16 nm in CCTO hollow fiber with 1.0 wt.% CCTO. In addition, the tensile strength of HFS was significantly improved from 4.84 MPa to 5.54 MPa and elongation at break was decreased from 6.97 % to 5.09 % which is ascribed to the reduction in porosity. All the results indicated the significant effect of CCTO content on properties of CCTO hollow fibers. The finding in this study could lead to a new direction to enhance the properties of HFS with potential application in membranes.

Preparation and Characterization of Alginate/Polyvinyl Alcohol Composite Fibers Containing Copper Ions

2013 ◽  
Vol 652-654 ◽  
pp. 1562-1565 ◽  
Author(s):  
Jing Guo ◽  
Qian He Chen ◽  
Yu Yan Zhang ◽  
Yu Mei Gong ◽  
Hong Zhang
Keyword(s):  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Copper Ions ◽  
Fiber Surface ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Pseudoplastic Fluid ◽  
Cu Ions

Alginate/polyvinyl alcohol (PVA) composite fibers containing copper ions were prepared by wet spinning. The spinning solution and manufacturing process were researched. The composite fibers were characterized by Tensile Strength Tester, SEM and TGA. This report shows that the spinning solution is a typical kind of pseudoplastic fluid. Adding boric acid to coagulation bath and putting Cu ions into composite fibers can improve the strength. The structure of composite fibers with Cu ions is denser and there are grooves on the fiber surface. In addition, the thermal property of composite fibers is steady.

scholarly journals Antimicrobial Polymeric Materials; Cellulose and m-Aramid Composite Fibers

2007 ◽  
Vol 2 (4) ◽  
pp. 155892500700200 ◽  
Author(s):  
Jaewoong Lee ◽  
R. M. Broughton ◽  
S. D. Worley ◽  
T. S. Huang
Keyword(s):  
Mechanical Properties ◽  
Antimicrobial Activity ◽  
Polymeric Materials ◽  
Composite Fiber ◽  
Wet Spinning ◽  
Gram Negative Bacteria ◽  
Composite Fibers ◽  
Aramid Fibers ◽  
Gram Negative ◽  
Chlorine Bleach

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.

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
Keyword(s):  
Mechanical Properties ◽  
Wet Spinning ◽  
Composite Fibers

Preparation of R-BABP Polyimide Fibers via Wet Spinning of Polyamide Acid

2020 ◽  
Vol 869 ◽  
pp. 266-272
Author(s):  
Gleb Vaganov ◽  
Andrei Didenko ◽  
Elena Ivan’kova ◽  
Elena Popova ◽  
Vladimir Elokhovskii ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ethylene Glycol ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Structure And Properties ◽  
Polyimide Fibers ◽  
Thermal Imidization ◽  
Morphology And Mechanical Properties

A polyamide acid (PAA) based on diamine 4,4'-bis (4-aminophenoxy) diphenyl and 1,3-bis (3',4-dicarboxyphenoxy) benzene dianhydride was synthesized. PAA fibers were obtained by wet spinning. Then, these fibers were converted into polyimide by thermal imidization. Dependence of the structure and properties of fibers on the die drawing and the composition of the coagulation bath was studied. It is shown that the composition of the coagulation bath has a significant effect on the morphology and mechanical properties of polyimide (PI) fibers. To obtain defect-free fibers, a coagulation bath consisting of ethylene glycol/ethanol at 50/50 vol. % was found to be optimal. An increase in the die drawing of fibers from 1 to 2 times leads to an increase in tensile strength and strain at break of the polyimide fibers.

scholarly journals The Impact of Shear and Elongational Forces on Structural Formation of Polyacrylonitrile/Carbon Nanotubes Composite Fibers during Wet Spinning Process

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2797 ◽  
Author(s):  
Hamideh Mirbaha ◽  
Parviz Nourpanah ◽  
Paolo Scardi ◽  
Mirco D’incau ◽  
Gabriele Greco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Young’S Modulus ◽  
Shear Force ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Wet Spinning ◽  
Composite Fibers ◽  
Pan Fibers ◽  
Spun Fibers

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.

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