scholarly journals Study on the Morphologies and Formational Mechanism of Poly(hydroxybutyrate-co-hydroxyvalerate) Ultrafine Fibers by Dry-Jet-Wet-Electrospinning

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Shuqi Zhu ◽  
Hao Yu ◽  
Yanmo Chen ◽  
Meifang Zhu
Keyword(s):  
Fiber Surface ◽  
Double Diffusion ◽  
Electrospun Fibers ◽  
Surface Porosity ◽  
Morphological Comparison ◽  
Ultrafine Fibers ◽  
Stability And Instability ◽  
Boundary Of Stability

Dry-jet-wet-electrospinning (DJWE) was carried out to study the formational mechanism of poly(hydroxybutyrate-co-hydroxyvalerate) electrospun fibers. Morphological comparison between normal electrospinning (NE) and DJWE was investigated. The results showed that jet could solidify quickly in DJWE to avoid bead collapse or fiber coherence. Jet structures could be maintained at very low collection distance. Beanpod-like beads, which were named as primary beads, could be seen at the boundary of stability and instability section and divided into spindle-like beads with longer collection distance. Bead-free electrospun fibers from DJWE had few bonding points among each other, and fast solidification and double-diffusion led to rough and shriveled fiber surface. DJWE mats were higher hydrophobic than that from NE due to more loose structure and higher surface porosity. Higher bead ratio on the surface and rounder bead structure resulted in higher hydrophobicity.

Development of a novel preparation method for conductive PES ultrafine fibers with self-formed thin PES/CNTs composite layer by vapor treatment

RSC Advances ◽  
2015 ◽  
Vol 5 (53) ◽  
pp. 42305-42310 ◽  
Author(s):  
Zhimei Wei ◽  
Minle Peng ◽  
Fang Qiu ◽  
Xiaojun Wang ◽  
Shengru long Shengru long ◽  
...  
Keyword(s):  
Preparation Method ◽  
Composite Layer ◽  
Electrospun Fibers ◽  
Ultrafine Fibers ◽  
Widespread Interest ◽  
Vapor Treatment

Conductive electrospun fibers have attracted widespread interest in the field of electromagnetics.

The Melt Electrospinning of Polycaprolactone (PCL) Ultrafine Fibers

2008 ◽  
Vol 1134 ◽  
Author(s):  
Chitrabala Subramanian ◽  
Samuel C. Ugbolue ◽  
Steven B. Warner ◽  
Prabir K. Patra
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Process Parameters ◽  
Applied Voltage ◽  
Fiber Diameter ◽  
Diameter Distribution ◽  
Electrospun Fibers ◽  
Ultrafine Fibers ◽  
Melt Electrospinning ◽  
Fiber Diameter Distribution

AbstractElectrospinning is a technique of producing nanofibers from polymer solution/melt solely under the influence of electrostatic forces. In this research, we investigated the formation of nanofibers by melt electrospinning polycaprolactone (PCL). The effect of process parameters such as molecular weight, applied voltage, and electrode separation on the fiber diameter was investigated. Controlling the process parameters could help increase the proportion of ultrafine fibers in the melt electrospun nonwoven mat. The velocity of the straight jets was in the range of 0.2-1 m/s. The melt electrospun fibers were characterized with respect to fiber diameter, distribution, mechanical properties and birefringence. Melt electrospun polycaprolactone fibers had a diameter distribution of the order of 5 -20 μm. The birefringence of the melt electrospun fibers increased with decrease in fiber diameter.

Microscopy Study of Morphology of Electrospun Fiber-MOF Composites with Secondary Growth

MRS Advances ◽  
2017 ◽  
Vol 2 (46) ◽  
pp. 2457-2463 ◽  
Author(s):  
Mitchell R. Armstrong ◽  
Bohan Shan ◽  
Bin Mu
Keyword(s):  
Electrospun Fiber ◽  
Metal Organic Framework ◽  
Secondary Growth ◽  
Fiber Surface ◽  
Microscopy Study ◽  
Electrospun Fibers ◽  
Crystal Formation ◽  
Growth Method ◽  
Metal Organic ◽  
Particle Incorporation

ABSTRACTMicroscopy studies were performed over a series of metal-organic-framework (MOF) imbedded electrospun fibers. Analysis of as-spun fibers revealed five different MOF particle-fiber imbedded morphologies including complete particle encasement, over-filled, surface-bound, welded, and agglomerated. To mitigate issues with fiber breakup during electrospinning (ES) due to MOF particle incorporation, secondary growth method was used. Secondary growth was performed on both Matrimid and polysulfone fibers impregnated with a MOF, ZIF-8, in either water or methanol solvents. Results show that when water was used, crystal formation was limited to formation on the top layer of the fiber mat due to hydrophobicity. When methanol was used in place of water, MOF crystal growth occurred in a patchwise manner, where crystals grow across fibers and span the entire fiber mat. From this work, it was determined that successful secondary growth of MOF imbedded electrospun fibers can be accomplished when particles are either highly exposed along the fiber surface for adequate exposure to solvent, or the solvent used promotes reactant penetration into the polymer to allow access to the seeded MOF crystals.

scholarly journals Application of Electrospun Nanofiber Membrane in the Treatment of Diabetic Wounds

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 6
Author(s):  
Zhaoju Gao ◽  
Qiuxiang Wang ◽  
Qingqiang Yao ◽  
Pingping Zhang
Keyword(s):  
Fiber Surface ◽  
Electrospun Nanofibers ◽  
Electrospun Fibers ◽  
Pathological State ◽  
Electrospun Nanofiber ◽  
Delayed Wound Healing ◽  
New Ideas ◽  
Application Potential ◽  
And Migration ◽  
Diabetic Wounds

Diabetic wounds are complications of diabetes which are caused by skin dystrophy because of local ischemia and hypoxia. Diabetes causes wounds in a pathological state of inflammation, resulting in delayed wound healing. The structure of electrospun nanofibers is similar to that of the extracellular matrix (ECM), which is conducive to the attachment, growth, and migration of fibroblasts, thus favoring the formation of new skin tissue at the wound. The composition and size of electrospun nanofiber membranes can be easily adjusted, and the controlled release of loaded drugs can be realized by regulating the fiber structure. The porous structure of the fiber membrane is beneficial to gas exchange and exudate absorption at the wound, and the fiber surface can be easily modified to give it function. Electrospun fibers can be used as wound dressing and have great application potential in the treatment of diabetic wounds. In this study, the applications of polymer electrospun fibers, nanoparticle-loaded electrospun fibers, drug-loaded electrospun fibers, and cell-loaded electrospun fibers, in the treatment of diabetic wounds were reviewed, and provide new ideas for the effective treatment of diabetic wounds.

Electrospinning Using Solution of Waste Polyacrylonitrile

2014 ◽  
Vol 1065-1069 ◽  
pp. 3136-3139
Author(s):  
Chun Xue Zhang ◽  
Bo Sun
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Fiber Diameter ◽  
Electrospun Fibers ◽  
Fiber Structure ◽  
Ultrafine Fibers ◽  
Ultrafine Fiber ◽  
Dimethylformamide Solution ◽  
Scanning Electron

Polyacrylonitrile (PAN) ultrafine fiber was prepared by electrospinning of PAN solution made from waste PAN. Diameters of the electrospun fibers as well as distribution of them were characterized by scanning electron microscope. The results show that the waste polyacrylonitrile/ N,N-dimethylformamide solution can be used for electrospinning after simply treatment-filtration. Uniform ultrafine fibers with diameters between 100 nm and 250nm could be obtained. With increasing concentration of waste PAN from 9% to 10%, the morphology was changed from beaded fiber to uniform fiber structure and the fiber diameter was also increased from110nm to 184 nm gradually. A narrow distribution of fiber diameters was observed at a voltage of 22kV. However, more beaded fibers were observed for longer tip–collecting foil distance.

Genetically engineering of Escherichia coli and immobilization on electrospun fibers for drug delivery purposes

2016 ◽  
Vol 4 (42) ◽  
pp. 6820-6829 ◽  
Author(s):  
Songzhi Xie ◽  
Sihan Tai ◽  
Haixing Song ◽  
Xiaoming Luo ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Delivery ◽  
Covalent Binding ◽  
Fiber Surface ◽  
Coaxial Electrospinning ◽  
Electrospun Fibers ◽  
Affinity Adsorption

Engineered EcN bacteria were entrapped in core-sheath fibersviacoaxial electrospinning or grafted on the fiber surfaceviacovalent binding or affinity adsorption.

Poly(Lactic Acid) (PLA) Electrospun Fibers Containing Rice Extract: Release Characteristics and their Antioxidant Activity

2017 ◽  
Vol 757 ◽  
pp. 83-87 ◽  
Author(s):  
Piyachat Chuysinuan ◽  
Nitirat Chimnoi ◽  
Lalita Pattani ◽  
Panita Khlaychan ◽  
Patcharakamon Nooeaid ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Lactic Acid ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Fiber Surface ◽  
Electrospinning Process ◽  
Poly Lactic Acid ◽  
Electrospun Fibers ◽  
Fiber Mats ◽  
Negative Effect

This study aimed to fabricate electrospun poly(lactic acid) (PLA) fiber mats containing 3 kinds of rice extract (rice bran, riceberry and LeumPhum rice extracts) by using electrospinning. The rice extract has been reported to exhibit antioxidant activities. The neat and rice extract-loaded PLA fiber mats were smooth and no beads formed on the fiber surface with diameters ranging from 450-656 nm. Release characteristics of the rice extract-loaded electrospun PLA fiber mats were investigated using total immersion methods. The scavenging ability of LeumPhum rice extract-loaded electrospun fibers showed superior scavenging activity as determined using the DPPH radical scavenging method. The results suggested that rice extract incorporated in PLA nanofibers had no negative effect on antioxidant activity when using an electrospinning process.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

Anisotropic Membranes as Substrates for Sem

1976 ◽  
Vol 34 ◽  
pp. 444-445
Author(s):  
Thomas P. Turnbull ◽  
W. F. Bowers
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Flow ◽  
Polymer Chemistry ◽  
Surface Porosity ◽  
Transmission Electron ◽  
Pore Texture ◽  
Spongy Layer ◽  
Scanning Electron

Until recently the prime purposes of filters have been to produce clear filtrates or to collect particles from solution and then remove the filter medium and examine the particles by transmission electron microscopy. These filters have not had the best characteristics for scanning electron microscopy due to the size of the pores or the surface topography. Advances in polymer chemistry and membrane technology resulted in membranes whose characteristics make them versatile substrates for many scanning electron microscope applications. These polysulphone type membranes are anisotropic, consisting of a very thin (0.1 to 1.5 μm) dense skin of extremely fine, controlled pore texture upon a much thicker (50 to 250μm), spongy layer of the same polymer. Apparent pore diameters can be controlled in the range of 10 to 40 A. The high flow ultrafilters which we are describing have a surface porosity in the range of 15 to 25 angstrom units (0.0015-0.0025μm).

Sign in / Sign up

Export Citation Format

Share Document