Electrospinning
“Electrospinning uses an electrical charge to draw very fine (typically on the micro or nano scale) fibers from a liquid. Electrospinning shares characteristics of both electrospraying and conventional solution dry spinning[1] of fibers. The process is non-invasive and does not require the use of coagulation chemistry or high temperatures to produce solid threads from solution. This makes the process particularly suited to the production of fibres using large and complex molecules. Electrospinning from molten precursors is also practised; this method ensures that no solvent can be carried over into the final product.”
“When a sufficiently high voltage is applied to a liquid droplet, the body of the liquid becomes charged, and electrostatic repulsion counteracts the surface tension and droplet is stretched, at a critical point a stream of liquid erupts from the surface. This point of eruption is known as the Taylor cone “
“If the molecular cohesion of the liquid is sufficiently high, stream breakup does not occur (if it does, droplets are electrosprayed) and a charged liquid jet is formed. As the jet dries out in flight, the mode of current flow changes from ohmic to convective as the charge migrates to the surface of the fibre. The jet is then elongated by a whipping process caused by electrostatic repulsion initiated at small bends in the fibre, until it is finally deposited on the grounded collector. The elongation and thinning of the fibre resulting from this bending instability leads to the formation of uniform fibres with nanometer-scale diameters.”
Wikipedia, Electrospinning (7/23/2010)
Bubble Electrospinning
Coaxial Electrospinning
Edge Electrospinning
Electrospinning Fluorinated Materials
Electrospinning Polyacrylonitriles (PAN)
Electrospinning Polyamides
Electrospinning Polycarbonates
Electrospinning Polyesters
Electrospinning Polyethylene
Electrospinning Polyethylene Oxide
Electrospinning Polymethylmethacrylate (PMMA)
Electrospinning Solutions
Electrospinning Suspensions
Electrospinning Tissue Scaffolds
Gas Assisted Electrospinning
Nanofibers
Polyimide Nanofibers
Polystyrene (PS) Nanofibers
Processing
Quantum Dots in Nanofibers
Spinning
Recent US Patents
10/19/2010
7,815,427
Apparatus and method for reducing solvent loss for electro-spinning of fine fibers
Green, King and Li of Clarco, Ohio formed fine fibers via electro-spinning from a polymer solution by dipping the spray or spinning electrode in a polymer solution. (RDC 1/18/2011)
10/5/2010
7,807,094
Process of preparing continuous filament composed of nanofibers
Kim and Park of South Korea have produced producing a continuous filament made up of nanofibers by electrospinning onto an endless grooved belt with conductive material inserted into the moving grooves. (RDC 12/20/2010)
Recent Journal Articles
1/7/2011
Fabrication of Microropes via Bi-electrospinning with a Rotating Needle Collector
(2151–2154)Macromolecular Rapid Communications 31 #24 (2010)
Chang and Shen fabricated double helical nanofilament microropes with diameters of less than 10µm and lengths up to 5cm by a modified bi-electrospinning technique. The helicity of the microropes can be varied easily by adjusting the distance between two spinnerets. (RDC 1/15/2011)
12/3/2010
Electrospun collagen–chitosan–TPU nanofibrous scaffolds for tissue engineered tubular grafts
(307-315) Colloids and Surfaces B: Biointerfaces 82 #2 (2010)
Huang et al attempted to design a novel kind of scaffolds for blood vessel and nerve repairs. Random and aligned nanofibrous scaffolds based on collagen–chitosan–thermoplastic polyurethane (TPU) blends were electrospun to mimic the componential and structural aspects of the native extracellular matrix, while an optimal proportion was found to keep the balance between biocompatibility and mechanical strength. The scaffolds were crosslinked by glutaraldehyde (GTA) vapor to prevent them from being dissolved in the culture medium. Cell viability studies with endothelial cells and Schwann cells demonstrated that the blended nanofibrous scaffolds formed by electrospinning process had good biocompatibility and aligned fibers could regulate cell morphology by inducing cell orientation. Results indicated that collagen–chitosan–TPU blended nanofibrous scaffolds might be a potential candidate for vascular repair and nerve regeneration. (RDC 12/6/2010)
Review Articles
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