Saturday, July 05, 2008

Electrospinning video




May 26, 2008 Electrospinning PAN/DMF solution. Electric field: 1.5 kV/cm. Needle: 22G. Feeding rate: 0.1 mL/m. For more info about electrospinning...


Fabrication and characterization of a boehmite nanoparticle

Garudadhwaj Hota Æ B. Rajesh Kumar Æ
W. J. Ng Æ S. Ramakrishna

Abstract
The fabrication of a composite electrospun
fiber membrane with sorptive characteristics intended for
removal of heavy metals was investigated. The electrospun
fiber membrane was impregnated with nano-boehmite
particles. The latter had been selected to increase surface
area of the active component. Cd (II) was chosen as the
challenge bivalent cation. The sorption capacity of the
nano-boehmite was studied as a function of pH and time.
Electrospinning was used to prepare the composite submicron
fiber membrane impregnated with boehmite
nanoparticles. The later was blended with the polymer to
produce a homogenous mixture before electrospinning.
Two polymers, the hydrophobic/PCL/and hydrophilic/
Nylon-6/, were chosen to serve as the support for the
boehmite. The nanoparticles and resulting composite
membranes were characterized using SEM, TEM, and
XRD techniques. XRD data confirmed the presence of
nano-boehmite particles in the nanofibers membrane. The
membranes so prepared were challenged with aqueous
solutions of Cd in batch isotherm tests. Atomic absorption
spectroscopy results show sorption of Cd (II) by boehmite
impregnated electospun membrane was possible and a
capacity of 0.20 mg/g was achieved.

Reference:
Contact Information Garudadhwaj Hota
Email: garud31@yahoo.com
Email: garud@nitrkl.ac.in

References

1. Hodi M, Polyak K, Hlavay J (1995) Environ Int 21:325
CrossRef ChemPort

2. Demarco MJ, Sengupta AK, Greenleaf JE (2003) Water Res 37:164
CrossRef ChemPort

3. Sierra-Alvarez R, Field JA, Cortinas I, Feijoo G, Moreira MT, Kopplin M, Gandolfi AJ (2005) Water Res 39:199
CrossRef ChemPort

4. Cervera ML, Arnal MC, Gurdia MDL (2003) Anal Bioanal Chem 375:820

5. Bishnoi NR, Bajaj M, Sharma N, Gupta A (2004) Bioresour Technol 91:305
CrossRef ChemPort

6. Potgieter JH, Potgieter-Vermaak SS, Kalibantonga PD (2006) Miner Eng 19:463
CrossRef ChemPort

7. Christophi CA, Axe L (2000) J Environ Eng 126:66
CrossRef ChemPort

8. Tilaki D, Ali R (2003) Diffuse pollution conference Dublin 8–35

9. Xu Y, Axe L (2005) J Colloid Interface Sci 282:11
CrossRef ChemPort

10. Naskar MK, Chatterjee M (2005) J Am Ceram Soc 88:3322
CrossRef ChemPort

11. Park JH, Lee MK, Rhee CK, Kim WW (2004) Mater Sci Eng A 375–377:1263

12. Zhu HY, Gao XP, Song DY, Bai YQ, Ringer SP, Gao Z, Xi YX, Martens W, Riches JD, Frost RL (2004) J Phys Chem B 108:4245
CrossRef ChemPort

13. Huang ZM, Zhang YZ, Kotaki M, Ramakrishna S (2003) Compos Sci Technol 63:2223
CrossRef ChemPort

14. Subbiah T, Bhat GS, Tock RW, Parameswaran S, Ramkumar SS (2005) J Appl Polym Sci 96:557
CrossRef ChemPort

15. Thandavamoorthy S, Gopinath N, Ramkumar SS (2006) J Appl Polym Sci 101:3121
CrossRef ChemPort

16. Chronakis IS (2005) J Mater Process Technol 167:283
CrossRef ChemPort

17. Sigmund W, Yuh J, Park H, Maneeratana V, Pyrgiotakis G, Daga A, Taylor J, Nino JC (2006) J Am Ceram Soc 89:395
CrossRef ChemPort

18. Yoon K, Kim K, Wang X, Fang D, Hsiao BS, Chu B (2006) Polymer 47:2434
CrossRef ChemPort

19. Son WK, Youk JH, Park WH (2006) Carbohydr Polym 65:430
CrossRef ChemPort

http://www.springerlink.com/content/4u5m58862368u14v/fulltext.pdf

Nanofibers and their applications in tissue engineering

Rajesh Vasita and Dhirendra S Katti
Department of Biological Sciences and Bioengineering, Indian Institute of Technology – Kanpur, Kanpur, Uttar Pradesh, India
Correspondence: Dhirendra S Katti Department of Biological Sciences and Bioengineering, Indian Institute of Technology – Kanpur, Kanpur-208016, Uttar Pradesh, India Tel +91 512 259 4028 Fax +91 512 259 4010 Email dsk@iitk.ac.in
Int J Nanomedicine. 2006 March; 1(1): 15–30.
PMCID: PMC2426767

Monday, June 30, 2008

Functional Self-Assembled Nanofibers by Electrospinning


A. Greiner1 and J. H. Wendorff1 Contact Information

(1) Department of Chemistry and Center of Material Science, Philipps-University, 35032 Marburg, Germany

Abstract Electrospinning constitutes a unique technique for the production of nanofibers
with diameters down to the range of a few nanometers. In strong contrast to conventional
fiber producing techniques, it relies on self-assembly processes driven by the Coulomb interactions
between charged elements of the fluids to be spun to nanofibers. The transition
from a macroscopic fluid object such as a droplet emerging from a die to solid nanofibers
is controlled by a set of complex physical instability processes. They give rise to extremely
high extensional deformations and strain rates during fiber formation causing among
others a high orientational order in the nanofibers as well as enhanced mechanical properties.
Electrospinning is predominantly applied to polymer based materials including
natural and synthetic polymers, but, more recently, its use has been extended towards
the production of metal, ceramic and glass nanofibers exploiting precursor routes. The
nanofibers can be functionalized during electrospinning by introducing pores, fractal
surfaces, by incorporating functional elements such as catalysts, quantum dots, drugs,
enzymes or even bacteria. The production of individual fibers, random nonwovens, or
orientationally highly ordered nonwovens is achieved by an appropriate selection of electrode
configurations. Broad areas of application exist in Material and Life Sciences for
such nanofibers, including not only optoelectronics, sensorics, catalysis, textiles, high efficiency
filters, fiber reinforcement but also tissue engineering, drug delivery, and wound
healing. The basic electrospinning process has more recently been extended towards compound
co-electrospinning and precision deposition electrospinning to further broaden
accessible fiber architectures and potential areas of application.
Keywords Co-electrospinning · Electrospinning · Fiber architectures · Functions and applications · Nanofibers · Nonwovens · Precision electrospinning



Paper Reference: http://www.springerlink.com/content/v80076257623ul64/fulltext.pdf

Fabrics made of functional nanofibers that would decompose toxic industrial chemicals into harmless byproducts.

Cornell fiber scientist Juan Hinestroza is working with the U.S. government to create fabrics made of functional nanofibers that would decompose toxic industrial chemicals into harmless byproducts.

Potential applications include safety gear for U.S. soldiers and filtration systems for buildings and vehicles.

Hinestroza, assistant professor of fiber science in the College of Human Ecology, is a member of two teams that secured more than $2.2 million from the U.S. Department of Defense;

about $875,000 will go directly to Hinestoza's work. Both grants are multi-university collaborative efforts funded through the U.S. Defense Threat Reduction Agency.

"These nanostructures could be used in creating advanced air filtration and personal protection systems against airborne chemical threats and can find many applications in buildings, airplanes as well as personal respirators," Hinestroza said.

The first project, in collaboration with North Carolina State University, is aimed at understanding how very small electrical charges present in fibers and nanofibers can help in capturing nanoparticles, bacteria and viruses.

"Understanding how these charges are injected into the fibers and how they are dissipated under different environmental conditions can open an avenue to significant improvements in air filtration technology," Hinestroza said.

The position and distribution of the electrical charges on the nanofibers will be fed into computerized fluid dynamics algorithms developed by Andrey Kutznetsov of NC State to predict the trajectory of the nanoparticles challenging the filter. Hinestroza and NC State's Warren Jasper pioneered work in this area a couple of years ago.

The second project, in collaboration with the University of California-Los Angeles (UCLA), will study the incorporation of a new type of molecules -- called metal organic polyhedra and metal organic frameworks -- onto polymeric nanofibers to trap dangerous gases as toxic industrial chemicals and chemical warfare agents, then decompose them into substances that are less harmful to humans and capture them for further decontamination. The synthesis of these molecules was pioneered by Omar Yaghi of UCLA.

This project will also look into the potential toxicity of these nanofiber-nanoparticle systems to humans in collaboration with Andre Nel from UCLA Medical School.

Hinestroza's research group specializes in understanding and manipulating nanoscale phenomena in fiber and polymer science. Related Information: Hinestroza Research Group

By Sheri Hall assistant communications director for the College of Human Ecology. Contact: Blaine Friedlander bpf2@cornell.edu 607-254-8093. Cornell University Communications

Cornell Chronicle: Susan Lang (607) 255-3613 ssl4@cornell.edu, Media Contact: Press Relations Office (607) 255-6074 pressoffice@cornell.edu