Modeling of spinning jet behavior and evaluation on fiber morphology for centrifugal spinning

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.

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Fiber Forming Capability of Binary and Ternary Compositions in the Polymer System: Bacterial Cellulose–Polycaprolactone–Polylactic Acid

Polymers ◽

10.3390/polym11071148 ◽

2019 ◽

Vol 11 (7) ◽

pp. 1148 ◽

Cited By ~ 5

Author(s):

Mehmet Onur Aydogdu ◽

Esra Altun ◽

Jubair Ahmed ◽

Oguzhan Gunduz ◽

Mohan Edirisinghe

Keyword(s):

Mechanical Properties ◽

Bacterial Cellulose ◽

Polylactic Acid ◽

Polymer System ◽

Product Yield ◽

Fiber Morphology ◽

Fibrous Scaffold ◽

Centrifugal Spinning ◽

High Concentrations ◽

Suitable System

Bacterial Cellulose (BC) has over recent decades shown great versatility in wound healing dressings, but is difficult to spin fibers with at high concentrations. An investigation into the preparation of bandage-like fibrous meshes is carried out to determine the optimal blend of polycaprolactone (PCL) and polylactic acid (PLA) as a suitable carrier for BC. Using a simple centrifugal spinning setup, polymer blends of PCL, PLA and BC are investigated as a ternary system to determine the most suitable composition with a focus on achieving maximal BC concentration. It is found that BC content in the fibers above 10 wt % reduced product yield. By creating blends of PLA-PCL fibers, we can create a more suitable system in terms of yield and mechanical properties. The fibrous samples are examined for yield, fiber morphology using scanning electron microscopy, mechanical properties using tensile testing and chemical characteristics using Fourier-transform infrared spectroscopy. A fibrous scaffold with > 30 wt % BC was produced with enhanced mechanical properties owing to the blending of PLA and PCL.

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Surface morphologies of electrospun polystyrene fibers induced by an electric field

Textile Research Journal ◽

10.1177/0040517518824843 ◽

2019 ◽

Vol 89 (18) ◽

pp. 3850-3859 ◽

Cited By ~ 3

Author(s):

Na Meng ◽

Yuansheng Zheng ◽

Binjie Xin

Keyword(s):

Electric Field ◽

Electric Fields ◽

Applied Voltage ◽

High Speed ◽

Three Dimensional ◽

Electrospinning Process ◽

Fiber Morphology ◽

Jet Behavior ◽

Working Distance ◽

Surface Morphologies

The electric field plays a key role in the formation of fibers during the electrospinning process. The electric field strength and shape caused by the applied voltage between the spinneret and collector govern the electrospinning process. In this study, a comprehensively designed and correctly implemented analysis was carried out to investigate the effects of the electric field on jet behavior and fiber morphology. Both working distance and applied voltage, respectively, were adjusted to manipulate the electric field shape and strength. The three-dimensional electric fields were simulated to understand the electric field distribution; in addition, a high-speed camera was adopted to capture the images of jet motion. Four parameters, namely straight jet length, envelope cone, height of the bending area, and velocity of the bending jet, were measured to describe the jet behavior. It can be revealed that the shape and strength of the electric field are responsible for the jet behavior and the fiber morphology, which include resultant ripples, grooves, and pores.

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Manipulating characteristic timescales and fiber morphology in simultaneous centrifugal spinning and photopolymerization

Polymer ◽

10.1016/j.polymer.2015.07.020 ◽

2015 ◽

Vol 73 ◽

pp. 42-51 ◽

Cited By ~ 26

Author(s):

Yichen Fang ◽

Austin D. Dulaney ◽

Jesse Gadley ◽

Joao M. Maia ◽

Christopher J. Ellison

Keyword(s):

Fiber Morphology ◽

Centrifugal Spinning

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SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079061 ◽

1977 ◽

Vol 35 ◽

pp. 308-309

Author(s):

K. W. Robinson

Keyword(s):

Tension Wood ◽

Wood Fiber ◽

Strength Properties ◽

Fiber Morphology ◽

Paper Properties ◽

Pure Cellulose ◽

Short Rotation ◽

Hardwood Trees ◽

Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

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Polymerization of Bolaform Butadiyne 1-Glucosamide in Self-Assembled Nanoscale-Fiber Morphology

Macromolecules ◽

10.1021/ma981053s ◽

1998 ◽

Vol 31 (26) ◽

pp. 9403-9405 ◽

Cited By ~ 52

Author(s):

Mitsutoshi Masuda ◽

Takeshi Hanada ◽

Kiyoshi Yase ◽

Toshimi Shimizu

Keyword(s):

Fiber Morphology ◽

Self Assembled

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Role of Surface Chemistry in the In Vitro Lung Response to Nanofibrillated Cellulose

Nanomaterials ◽

10.3390/nano11020389 ◽

2021 ◽

Vol 11 (2) ◽

pp. 389

Author(s):

Kukka Aimonen ◽

Satu Suhonen ◽

Mira Hartikainen ◽

Viviana R. Lopes ◽

Hannu Norppa ◽

...

Keyword(s):

Micronucleus Assay ◽

Nanofibrillated Cellulose ◽

In Vitro Toxicity ◽

Surface Functional Group ◽

Fiber Morphology ◽

Surface Charges ◽

Cell Viability Assay ◽

Wide Range ◽

Group Density

Wood-derived nanofibrillated cellulose (NFC) has emerged as a sustainable material with a wide range of applications and increasing presence in the market. Surface charges are introduced during the preparation of NFC to facilitate the defibrillation process, which may also alter the toxicological properties of NFC. In the present study, we examined the in vitro toxicity of NFCs with five surface chemistries: nonfunctionalized, carboxymethylated, phosphorylated, sulfoethylated, and hydroxypropyltrimethylammonium-substituted. The NFC samples were characterized for surface functional group density, surface charge, and fiber morphology. Fibril aggregates predominated in the nonfunctionalized NFC, while individual nanofibrils were observed in the functionalized NFCs. Differences in surface group density among the functionalized NFCs were reflected in the fiber thickness of these samples. In human bronchial epithelial (BEAS-2B) cells, all NFCs showed low cytotoxicity (CellTiter-GloVR luminescent cell viability assay) which never exceeded 10% at any exposure time. None of the NFCs induced genotoxic effects, as evaluated by the alkaline comet assay and the cytokinesis-block micronucleus assay. The nonfunctionalized and carboxymethylated NFCs were able to increase intracellular reactive oxygen species (ROS) formation (chloromethyl derivative of 2′,7′-dichlorodihydrofluorescein diacetate assay). However, ROS induction did not result in increased DNA or chromosome damage.

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Sequential Oxidation on Wood and Its Application in Pb2+ Removal from Contaminated Water

Polysaccharides ◽

10.3390/polysaccharides2020017 ◽

2021 ◽

Vol 2 (2) ◽

pp. 245-256

Author(s):

Priyanka R. Sharma ◽

Sunil K. Sharma ◽

Marc Nolan ◽

Wenqi Li ◽

Lakshta Kundal ◽

...

Keyword(s):

Adsorption Capacity ◽

Average Length ◽

Sodium Chlorite ◽

Contaminated Water ◽

Maximum Adsorption Capacity ◽

Fiber Morphology ◽

Carboxylate Groups ◽

Carboxylate Content ◽

Wide Range ◽

Length Width

Raw wood was subjected to sequential oxidation to produce 2,3,6-tricarboxycellulose (TCC) nanofibers with a high surficial charge of 1.14 mmol/g in the form of carboxylate groups. Three oxidation steps, including nitro-oxidation, periodate, and sodium chlorite oxidation, were successfully applied to generate TCC nanofibers from raw wood. The morphology of extracted TCC nanofibers measured using TEM and AFM indicated the average length, width, and thickness were in the range of 750 ± 110, 4.5 ± 1.8, and 1.23 nm, respectively. Due to high negative surficial charges on TCC, it was studied for its absorption capabilities against Pb2+ ions. The remediation results indicated that a low concentration of TCC nanofibers (0.02 wt%) was able to remove a wide range of Pb2+ ion impurities from 5–250 ppm with an efficiency between 709–99%, whereby the maximum adsorption capacity (Qm) was 1569 mg/g with R2 0.69531 calculated from Langmuir fitting. It was observed that the high adsorption capacity of TCC nanofibers was due to the collective effect of adsorption and precipitation confirmed by the FTIR and SEM/EDS analysis. The high carboxylate content and fiber morphology of TCC has enabled it as an excellent substrate to remove Pb2+ ions impurities.

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ALD coating of centrifugally spun polymeric fibers and postannealing: case study for nanotubular TiO2 photocatalyst

Nanoscale Advances ◽

10.1039/d1na00288k ◽

2021 ◽

Author(s):

Martina Rihova ◽

Oksana Yurkevich ◽

Martin Motola ◽

Ludek Hromadko ◽

Zdeněk Spotz ◽

...

Keyword(s):

Atomic Layer Deposition ◽

Atomic Layer ◽

Vinyl Pyrrolidone ◽

Tio2 Photocatalyst ◽

Polymeric Fibers ◽

Layer Deposition ◽

Centrifugal Spinning ◽

Poly Vinyl Pyrrolidone

This work describes the synthesis of highly photocatalytically active TiO2 tubes (TiTBs) by combining centrifugal spinning and atomic layer deposition (ALD). Poly(vinyl pyrrolidone) (PVP) fibers were first produced by centrifugal...

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The shear and compressive yield stress of fibrillated acacia pulp fiber suspensions

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2019-0065 ◽

2020 ◽

Vol 35 (2) ◽

pp. 243-250

Author(s):

Jiulong Sha ◽

Yueyue Yang ◽

Can Wang ◽

Wei Li ◽

Peng Lu ◽

...

Keyword(s):

Yield Stress ◽

Paper Industry ◽

Pulp Fiber ◽

Fiber Suspensions ◽

Fiber Morphology ◽

Shear Yield Stress ◽

Geometrical Properties ◽

Compressive Yield Stress ◽

Shear Yield ◽

Fiber Cell Wall

AbstractThe degree of interactions between fibers and the tendency of fibers to form flocs play an important role in effective unit operation in pulp and paper industry. Mechanical treatments may damage the structure of the fiber cell wall and geometrical properties, and ultimately change the fiber-fiber interactions. In this study, the gel crowding number, compressive and shear yield stress of fibrillated acacia pulps were investigated, and the results showed that the gel crowding number of the refined pulp samples ranged from 8.7 to 10.7, which were much lower than that of un-refined pulps. As the concentration increased, both the compressive yield stress {P_{y}} and shear yield stress {\tau _{y}} of all suspensions increased accordingly, and the yield stress was found to depend on a power law of the crowding number. Moreover, the values of {\tau _{y}}/{P_{y}} were also examined and the variation of {\tau _{y}}/{P_{y}} became largely dependent on the fiber morphology and mass concentration.

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