scholarly journals Influence of Polymer Concentration and Nozzle Material on Centrifugal Fiber Spinning

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 575 ◽  
Author(s):  
Jorgo Merchiers ◽  
Willem Meurs ◽  
Wim Deferme ◽  
Roos Peeters ◽  
Mieke Buntinx ◽  
...  
Keyword(s):  
Fiber Diameter ◽  
Polymer Concentration ◽  
Fiber Spinning ◽  
Fiber Morphology ◽  
Continuous Fiber ◽  
Fiber Mats ◽  
Promising Alternative ◽  
High Production Rate ◽  
Spinning Process ◽  
Centrifugal Fiber

Centrifugal fiber spinning has recently emerged as a highly promising alternative technique for the production of nonwoven, ultrafine fiber mats. Due to its high production rate, it could provide a more technologically relevant fiber spinning technique than electrospinning. In this contribution, we examine the influence of polymer concentration and nozzle material on the centrifugal spinning process and the fiber morphology. We find that increasing the polymer concentration transforms the process from a beaded-fiber regime to a continuous-fiber regime. Furthermore, we find that not only fiber diameter is strongly concentration-dependent, but also the nozzle material plays a significant role, especially in the continuous-fiber regime. This was evaluated by the use of a polytetrafluoroethylene (PTFE) and an aluminum nozzle. We discuss the influence of polymer concentration on fiber morphology and show that the choice of nozzle material has a significant influence on the fiber diameter.

Effects of Structural Parameters on Nanofiber from a Multihole Electrospinning Setup

2013 ◽  
Vol 690-693 ◽  
pp. 2886-2890 ◽  
Author(s):  
Yuan Sheng Zheng ◽  
Sheng Xie ◽  
Yong Chun Zeng
Keyword(s):  
Electric Fields ◽  
Electric Field Distribution ◽  
Fiber Diameter ◽  
Structural Parameters ◽  
Hole Array ◽  
Fiber Mats ◽  
High Production Rate ◽  
High Production ◽  
Production Requirement

To meet a high production requirement and high quality of nanofiber, a new disgned multihole spinneret with equilateral hexagon hole array of is used in this paper. We study the effects of two structural parameters of the multihole system on fiber diameter and fiber mats. 3D electric fields were simulated to understand the effects of electric field distribution on electrospinning performance. This study shows that fine and uniform fibers, as well as concentrated and uniform fiber mat can be obtained by this multihole electrospinning system at a high production rate.

Optimization of Solvent System and Polymer Concentration for Synthesis of Polyvinyl Alcohol (PVA) Fiber Using Rotary Forcespinning Technique

2015 ◽  
Vol 1123 ◽  
pp. 20-23 ◽  
Author(s):  
Muhammad Miftahul Munir ◽  
Ahmad Fauzi ◽  
Ade Yeti Nuryantini ◽  
Nursuhud ◽  
Eri Sofiari ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Fiber Diameter ◽  
Polymer Concentration ◽  
Solvent System ◽  
Polymer Fiber ◽  
Fiber Morphology ◽  
Ethanol Content ◽  
Optimization Parameters ◽  
Pva Fiber

Rotary forcespinning is one of techniques used for fabrication of polymer fiber. In this paper optimization of several parameters for synthesis of Polyvinyl Alcohol (PVA) fiber using rotary forcespinning technique was described. In order to obtain PVA fiber with smallest diameter the optimization parameters of solvent system and polymer concentration were performed. The results show that PVA dissolved in water as a single solvent produced fiber with high wettability. A mixture of water and ethanol as a solvent system was developed with variation in ethanol content. The effects of ethanol content on fiber diameter were investigated. Rotary forcespinning using solvent with ethanol content below 30% resulted in PVA fiber with high wettability, while solvent ethanol content of more than 70% was unable to dissolve PVA completely. The effect of PVA concentration on the fiber morphology was investigated by adjusting PVA concentration in the range of 9 to 13 weight %. The diameter of the PVA fiber was uniform and could be controlled by adjusting the PVA concentration.

Alternative solvent systems for polycaprolactone nanowebs via electrospinning

2016 ◽  
Vol 47 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Ipek Y Enis ◽  
Jakub Vojtech ◽  
Telem G Sadikoglu
Keyword(s):  
Formic Acid ◽  
Fiber Diameter ◽  
Polymer Concentration ◽  
Solvent System ◽  
Fiber Morphology ◽  
Solution System ◽  
Electrospinning Technique ◽  
Average Pore ◽  
Pore Analysis ◽  
Solvent Systems

In this study, polycaprolactone (PCL) was dissolved in 9:1 chloroform:ethanol mixture at 14%, 16%, 18% and 20% w/v concentrations. Then, acetic acid and formic acid were added at pre-determined amounts to 18% PCL/chloroform:ethanol solution system separately. Before production, viscosity and conductivity of prepared solutions were measured. Electrospinning technique was used for fabrication of fibrous webs. Morphology of produced webs was observed under a scanning electron microscope while fiber diameter measurements and pore analysis were realized via Image J Software System. The effect of polymer concentration and acidic solvent additions to mostly used chloroform solvent was investigated based on fiber morphology. Results indicate that the increase in polymer concentration increases the fiber diameter which leads to larger average pore area. Electrospinning of PCL with 16% to 20% polymer concentrations in chloroform:ethanol solvent system results in micro fibers. On the other hand, fiber diameter reduced from microscales to nanoscales with the addition of either acetic or formic acid. Fibers produced from PCL/chloroform:ethanol solution at 18% polymer concentration have 2.22 µm average fiber diameter, whereas 158 nm and 256 nm diameter fibers were successfully produced without a bead-like structure by 120 µl of acetic and formic acid additions to the same solution system.

Preparation of Fibrous Scaffolds Containing Calcium and Silicon Species

2011 ◽  
Vol 493-494 ◽  
pp. 840-843
Author(s):  
Akiko Obata ◽  
Hiroki Ozasa ◽  
Julian R. Jones ◽  
Toshihiro Kasuga
Keyword(s):  
Tissue Engineering ◽  
Hybrid Materials ◽  
Fiber Diameter ◽  
Fiber Spinning ◽  
High Porosity ◽  
Cotton Wool ◽  
Tissue Engineering Scaffolds ◽  
Large Defect ◽  
Nanofibrous Structure ◽  
Versatile Technique

Materials for bone defect filling should have 3D macroporous structure and be flexible to be packed into complex defects with limited entrance space. Tissue engineering scaffolds should also mimic the structure and morphology of the host tissue. Electrospinning is a versatile technique to produce materials with micro/nanofibrous structure, large surface area and high porosity. Electrospun materials are very promising for tissue engineering due to the possibility of mimicking the fibrous structure of natural extra cellular matrix (ECM). Siloxane-containing vaterite (SiV)/poly (L-lactic acid) (PLLA) hybrids (SiPVH) with controlled silicate and calcium ions releasing ability has been produced in our group. They have also demonstrated good cell infiltration into the electrospun hybrid materials that had fiber diameters greater than 10 μm. However, these electrospun hybrid materials were planar (2D) and are not suitable for large defect regeneration. In this work, the development of a fabrication technique for the production of 3D cotton wool-like structures with fiber diameter in the range of 10 μm was performed. SiPVH cotton wool-like structure containing 0, 30 and 60 wt % SiV were prepared by blowing air in the direction perpendicular to fiber spinning. Si-vaterite particles and small pores were found on the surface of the fibers. The fiber diameter of the samples were found to be in the range of 10 ~ 20 μm. Stretch tests showed more than 50 % extension for the SiPVH cotton wool-like material containing 30 wt % SiV (SiPVH30). This extension was similar to that observed for the PLLA cotton wool-like material. The results suggest that the SiPVH30 cotton wool-like material are good candidates for bone tissue engineering scaffolds.

scholarly journals Direct-Write Drawing of Carbon Nanotube/Polymer Composite Microfibers

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Scott M. Berry ◽  
Santosh Pabba ◽  
Robert W. Cohn ◽  
Robert S. Keynton
Keyword(s):  
Carbon Nanotube ◽  
Polymer Solutions ◽  
Fiber Diameter ◽  
Axial Strain ◽  
Polymer Concentration ◽  
Strain Rates ◽  
Direct Write ◽  
Composite Fibers ◽  
Capillary Thinning ◽  
Doped Polymer

Carbon-nanotube- (CNT-) doped polymer solutions were drawn into arrays of microfibers using a novel direct-write process. This process utilizes a micromanipulator-controlled syringe loaded with solvated polymer mixed with CNTs to “write” networks of composite fibers with precisely positioned endpoints. The diameters of these composite fibers are correlated to the degree of capillary thinning that occurs prior to the solidification of the directly written CNT-doped solution filament. The fibers had diameters ranging from 7 μm to over 100 μm and possessed conductivities as high as 0.1 Sm−1. Fiber diameter was found to increase with increasing polymer concentration and decreasing fiber length and can be controlled through modulation of these parameters. The presence of CNTs was found not to significantly affect fiber diameter, despite the CNTs significant effect on viscosity, which was previously reported to influence diameter. This discrepancy is likely related to the non-Newtonian effects of CNT/polymer solutions, including an apparent shear thinning at increasing axial strain rates.

scholarly journals Hierarchical spidroin micellar nanoparticles as the fundamental precursors of spider silks

2018 ◽  
Vol 115 (45) ◽  
pp. 11507-11512 ◽  
Author(s):  
Lucas R. Parent ◽  
David Onofrei ◽  
Dian Xu ◽  
Dillan Stengel ◽  
John D. Roehling ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Spider Silk ◽  
Fiber Spinning ◽  
Fiber Formation ◽  
Natural Material ◽  
Physical Form ◽  
Spinning Process ◽  
Black Widow Spiders ◽  
Spider Silks

Many natural silks produced by spiders and insects are unique materials in their exceptional toughness and tensile strength, while being lightweight and biodegradable–properties that are currently unparalleled in synthetic materials. Myriad approaches have been attempted to prepare artificial silks from recombinant spider silk spidroins but have each failed to achieve the advantageous properties of the natural material. This is because of an incomplete understanding of the in vivo spidroin-to-fiber spinning process and, particularly, because of a lack of knowledge of the true morphological nature of spidroin nanostructures in the precursor dope solution and the mechanisms by which these nanostructures transform into micrometer-scale silk fibers. Herein we determine the physical form of the natural spidroin precursor nanostructures stored within spider glands that seed the formation of their silks and reveal the fundamental structural transformations that occur during the initial stages of extrusion en route to fiber formation. Using a combination of solution phase diffusion NMR and cryogenic transmission electron microscopy (cryo-TEM), we reveal direct evidence that the concentrated spidroin proteins are stored in the silk glands of black widow spiders as complex, hierarchical nanoassemblies (∼300 nm diameter) that are composed of micellar subdomains, substructures that themselves are engaged in the initial nanoscale transformations that occur in response to shear. We find that the established micelle theory of silk fiber precursor storage is incomplete and that the first steps toward liquid crystalline organization during silk spinning involve the fibrillization of nanoscale hierarchical micelle subdomains.

Electrostatic-assisted centrifugal spinning for continuous collection of submicron fibers

2016 ◽  
Vol 87 (19) ◽  
pp. 2349-2357 ◽  
Author(s):  
Huanhuan Chen ◽  
XiangLong Li ◽  
Nan Li ◽  
Bin Yang
Keyword(s):  
Fiber Diameter ◽  
Electrostatic Force ◽  
Fiber Formation ◽  
Mechanism Analysis ◽  
Strongly Correlated ◽  
Fiber Morphology ◽  
Jet Trajectory ◽  
Centrifugal Spinning ◽  
Nozzle Size ◽  
Key Factor

Non-uniformity of the fiber diameter and difficulty in continuous web collection have limited the development and further application of centrifugal spinning (CS). Here, we present a feasible method for fibers' continuous collection and morphology optimization by utilizing vertical electrostatic-assisted centrifugal spinning (E-CS). The effects of spinning parameters, such as applied voltage, nozzle size, and rotational speed on fiber morphology have been evaluated systematically. We find that vertical voltage is strongly correlated with the formation of bead defects, and nozzle size is the most important parameter on fiber size, and the fiber diameter generally decreased with increasing rotation speed. Through the mechanism analysis and jet trajectory observation, we think that the Rayleigh–Taylor instability is the key factor in determining fiber formation in CS. When a vertical electrostatic force is applied to CS, the above instability phenomenon can be effectively controlled resulting more uniform fibers with thinner diameters and fewer beads.

Stability Analysis of the Fiber Spinning Process

1972 ◽  
Vol 16 (3) ◽  
pp. 519-533 ◽  
Author(s):  
J. R. A. Pearson ◽  
Y. T. Shah
Keyword(s):  
Stability Analysis ◽  
Fiber Spinning ◽  
Spinning Process
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