The formation of continuous aligned polymer fibers using electrospinning was discussed. The fibers were characterized using optical microscopy and scanning electron microscopy. In electrospinning, electrostatic force was applied between polymer solutions or melt kept in a pipette or a syringe, and a counter metal electrode kept at a distance. Results show that the use of a single sharp pin as a counter electrode, which helps to focus the fibers due to focusing electric field configuration, helps in achieving good alignment of fibers.

Venkatachalam Subramanian

Department Of Physics

Electric fields

Electric potential

Electrostatics

Optical microscopy

Plastic films

Polymethyl methacrylates

Polystyrenes

Scanning electron microscopy

Spinning (fibers)

Surface tension

Viscosity

electrospinning

FLOW RATES

Fibers

Fulltext

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Electrospinning of continuous aligned polymer fibers

Applied Physics Letters

The present work reports the preparation of Poly L-Lactide (PLLA) and Curcumin loaded Poly L-Lactide (CPLLA) nanofibers by electrospinning. A series of PLLA solution (12 wt%) and C-PLLA (12 wt% PLLA) solution containing Curcumin (0. 5 wt% and 1 wt%)) were electrospun into nanofibers. SEM images showed the average diameter of PLLA and C-PLLA in the range of 50-200 nm. The TEM images showed the dispersion of Curcumin on C-PLLA nanofibers. The XRD pattern indicated decreases of crystallinity with the increase in the amount of Curcumin. The characteristic peak of Curcumin was confirmed by FTIR. The TGA results showed the degradation of PLLA and C-PLLA close to 300 °C. The percentage porosity and the contact angle of PLLA were found to be 90. 2% and 115±3 ° with deionised water, respectively. The water uptake percentage was found to be 17. 6%. The percentage cumulative release of Curcumin at the end of 8th day for 0. 5 and 1. 0 wt% formulations was 81. 4±1. 3 and 86. 7±1. 7% respectively. The in-vitro biological cytotoxicity studies were performed using C6 glioma cells and NIH 3T3 fibroblast by MTT assay and SEM analysis. © 2012 The Korean Fiber Society and Springer Science+Business Media Dordrecht.

Fibers and Polymers

Fabrication of electrospun Poly L-lactide and Curcumin loaded Poly L-lactide nanofibers for drug delivery

Aligned nanocomposite electrospun fibers are investigated for electrical (dc, ac, and dielectric) and thermal properties (10-40 wt.). This nanocomposite consists of poly(methylmethacrylate) (PMMA) grafted core-shell magnetite (CSM) nanoparticles and PMMA. Electrical properties as a function of tunnel gap (in between the CSM nanoparticles) are studied as the polymer shell stays intact and the cores do not touch each other well above the percolation threshold. The depleted improvement in dc conductivity ( dcwt) with increasing wt. (the improvement percentage: dc10 to dc20 ≈ 100; dc20 to dc30 ≈ 40 and dc30 to dc40 ≈ 1.2) affirms the non-touching cores of CSM. Interestingly, the observed ac conductive behavior (0.1-13 MHz) in the high end of the frequency range is in clear contrast to that of a typical percolating system, in fact it does not explicitly follow the universal power law. Some of the obtained critical exponents are not accommodated by the universal theory and significantly different from the present theoretical/experimental predictions. Additionally, an improvement in thermal stability of ∼30 C and an overall increase in glass transition temperature are reported. © 2011 American Institute of Physics.

Journal of Applied Physics

Non-universal behavior well above the percolation threshold and thermal properties of core-shell-magnetite-polymer fibers

Composite fibers of single walled carbon nanotubes dispersed in poly(methyl methacrylate) and polystyrene are prepared using electrospinning. The single fiber electrical conductivity is measured as a function of the composition of carbon nanotubes. A noncontact method of measuring the carrier mobility at microwave frequency (14 GHz) using bimodal cavity is employed. The mobility measurements indicate lower percolation threshold for mobility compared to electrical conduction. For higher concentrations of carbon nanotubes, the mobility is found to decrease indicating possible carrier-lattice scattering. © 2008 American Institute of Physics.

Microwave Hall mobility studies on polymer-single walled carbon nanotube composite fibers

Electrospinning is a simple technique to prepare polymer fibers in nanometer diameters using very high electrostatic fields. These nanofibers are useful in many applications since the surface area to volume ratio in these fibers is very high. Here we have prepared nanofibers of composites of Polystyrene (PS) with different concentrations (0.05% to 2% w/w) of multi-walled carbon nanotubes (MWCNT) by electrospinning. The fibers are characterized by SEM, TEM, Raman spectra, and TGA. The room temperature electrical conductivity of single fibers of these composites are measured and found to show dramatic improvement in the conductivity due to the addition of MWCNT to the polymer matrix compared to the pure PS. Copyright © 2007 American Scientific Publishers All rights reserved.

Journal of Nanoscience and Nanotechnology

Preparation and characterization of polystyrene-multiwalled carbon nanotube composite fibers by electrospinning

Conducting polymer composites are useful in many applications such as sensors, EMI shielding, etc. In this report a composite of Nylon-6 (Ny-6) polymer doped with copper(II) chloride (CuCl2) is used to prepare the nanofibers by electrospinning. The electrospun nanofibers were characterized by IR spectra and the surface morphology is studied using scanning electron microscopy (SEM). An average diameter of the nanofibers is estimated to be 54 nm. Nanofibers of Ny-6 are prepared with different levels of doping of CuCl2 (10, 20, 30 and 40 wt%). DC resistance, AC impedance and capacitance measurements in the frequency range of 105-107 Hz are carried out on the nanofibers at room temperature. The results of these measurements are discussed. © 2007 Elsevier B.V. All rights reserved.

Materials Science and Engineering B: Solid-State Materials for Advanced Technology

Preparation and characterization of electrospun nanofibers of Nylon-6 doped with copper(II) chloride

Journal	Applied Physics Letters
ISSN	00036951
Open Access	No