Spring Meeting – May 23-25, 2001 Book of Abstracts – Posters and Presentations




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The Fiber Society

New Frontiers in Fiber Science

Spring Meeting – May 23-25, 2001

Book of Abstracts – Posters and Presentations



Organized by:

Nonwovens Cooperative Research Center


Part I

Textile Fibers and Nonwoven Webs - the Keys for Creating the Next Industrial Revolution

W. John G. McCulloch

Parametric Study of Electrostatic Fiber Formation

Gregory C. Rutledge1, Michael Y. Shin2, Moses M. Hohman3 and Michael Brenner4

Electrospinning of Nanofibers from Polymer Solutions and Melts

A.L. Yarin

Electrospinning

Steven B. Warner, Samuel C. Ugbolue, Prabir K. Patra, Alexandre Buer, Veli E. Kalayci, and Yong K. Kim

Spinning Fine Fibers From Solutions And The Melt Using Electrostatic Fields

R. A. A. Couillard, Z. Chen, and P. Schwartz

Functionalized nano- and mesotubes utilizing electrospun fibers (TUFT-process)

H. Hou, M. Bognitzki, J. Zeng, H. Wickel. A. Greiner

Electrospinning and Nanofibers

Darrell H. Reneker, Alexander Yarin,* Edward A. Evans**, Woraphon Kataphinan, Ratthapol Rangkupan, Wenxia Liu, Sureeporn Koombhongse, and Han Xu


Part II

Electrospinning of Nanostructured Composite Fibers

Dersch, M. Steinhart, A. Greiner, J. H. Wendorff

Electrospinning of Biomaterials

G. L. Bowlin,1 J. A. Matthews,2 D. G. Simpson,3 E.-R. Kenawy,4 and G. E. Wnek4

Nano-structured Electronspun Poly-D,L-lactide-co-glycolide Memberanes for Antiadhesion Applications

Dufei Fang, Xinhua Zong, Wander Chen, Sharon Cruz, Benjamin Hsiao* and Benjamin Chu*

The Relationship of Berry Number to the Diameter of PLA Fibers

Frank Ko , Baohua Han, Kinnari Chandriani, and Alan MacDiarmid*

In Search of Excellence in Textiles

Arun Pal Aneja

Mechanical Characteristics of Cellulose filaments oxidized in nitrogen dioxide(IV) - carbon tetrachloride

Yurkshtovich N., Chechovski A., Golub N., Kosterova R.

Effect of Electrospinning Material and Conditions upon Residual Electrostatic Charge of Polymer nanofibers

Peter P. Tsai & Heidi L. Schreuder-Gibson

Extrusion and Analysis of Nylon/Montmorillonite Nanocomposite Filaments

Marian G. McCord, Suzanne N. Rodden, Samuel M. Hudson

Cellulosic Nanofiber Membranes for Liquid Wetting/Absorbency and Chemical Reactitivity

Haiqing Liu & You-Lo Hsieh


Part III

PA-6 Clay nanocomposite hybrids for textile yarn processing

Serge Bourbigot(a), Eric Devaux(a), Jeffrey W. Gilman(b) and Ahmida El Achari(a)

Surface Coating of Poly(meta-phenylene isophthalamide) Nanofibers

Wenxia Liu, Darrell H. Reneker and Edward A. Evans

Surface Modification of Ultra-High-Strength Polyethylene Fibers

S. Nam and A. N. Netravali

Heat and Fire Resistance Of High Performance Fibers And Blends Of Them With Wool

Serge Bourbigot, Xavier Flambard, Manuela Ferreira

Franck Poutch

Cut Resistance of Multi-Layered Knitted Structures

Xavier Flambard* and Jean Polo

Modification of nylon Fabrics with Atmospheric Pressure Plasmas

L.K. Canup(1) , M. McCord(1), P. Hauser(1), Y. Qiu(1), J. Cuomo(2), O. Hankins(3) and M.A. Bourham(3)

Structure/Property Relationships for Poly (trimethylene terephthalate) (PTT) Fibers Spun at High Spinning Speeds

Richard Kotek, Dong-Wook Jung, C. B. Smith,


Part IV

PET versus PEN: What difference Can a Ring Make?

Alan E. Tonelli

Transverse Compression of PPTA Fibers

James Singletary, Hawthorne Davis, Warren Knoff, M. K. Ramasubramanian

Yarns of Basalt Continuous Fibers

A.N. Lisakovski, Y.L. Tsybulya & A.A. Medvedyev

Properties and Processing of Plant Fiber

Chongwen Yu

Computer simulation of needled nonwoven mechanical behaviour

B. Maze, d. Adolphe, j.-y. Drean

Polyblending for the Production of Dyeable Polypropylene Fibers

Badrossamay1,M.R., Amirshahi2, S.H., Morshed2, M. and Bidoki1, S.M.

Workskill Development in Introductory Textile Classes

Brian George, John D. Pierce, Eileen Armstrong-Carroll, Matt Dunn, & Christopher M. Pastore

Laser Fusion of Textured Yarns to Impart Inter-filament Cohesion

M. Acar, WL Dudeney, MR Jackson & W Malalasekera


Electrospinning of Nanostructured Composite Fibers

Dersch, M. Steinhart, A. Greiner, J. H. Wendorff,



Chemistry Department and Material Science Center

Philipps-University

Marburg, Germany


Electrospinning from polymer solutions yields fibers with very small diameters down to the range of several 10 nm. For a variety of applications it is desirable to produce such fibers with well defined surface topologies. Rough surfaces, pores or modulations of the chemical composition will not only contribute to larger surface to volume ratios. Such features will, in principle, affect the wetting behavior, the adsorption of specific molecules and the packing of such fibers in arrays. Fibers with specific surface topologies are also of interest as templates for the manufacturing of tubes (1). We have used three different approaches within the framework of electrospinning to obtain surface modulated fibers.


The first approach consists of selecting solvents with low vapor pressures for the polymer solutions (2). Phase separation takes place during the rapid spinning process induced by the evaporation of the solvent. The resulting fibers are characterized by the presence of pores and pits in the nm range. The density of the pores depends on the vapor pressure of the solvent. Typical examples are polycarbonate, polyvinylcarbazole and polylactide fibers spun from solution at room temperature (Figure 1)


The second approach uses ternary solutions of two immiscible polymers and a cosolvent. Phase separation induced by the evaporation of the solvent during the spinning process results in fibers with well defined spinodal phase morphologies. Continuous residual fibers can be obtained by selective removal of one of the polymer components either by heat treatment, by the use of selective solvents or by UV-light exposure. These fibers display a porous structure with pores extending to the fiber core. Examples of suitable polymer pairs are polystyrene and polymethylmethacrylate, polylactide and polyvinylpyrrolidone or polylactide and polyethyleneoxide.


The third approach consists in the co-electrospinning of colloidal particles and a polymer starting from a solution. The colloidal partakes have been found to be incorporated in the fibers as beads in a necklace.


References

Polymer, Metal and Hybrid Nano- and Mesotubes by Coating of Degradable Polymer Template Fibers (TUFT-process), M. Bognitzki, H. Hou, M. Ishaque, Th. Frese, M. Hellwig, Ch. Schwarte, A. Schaper, J. H. Wendorff, A. Greiner, Adv. Mater. 12, 637 (2000).

Nanostructured Fibers via Electrospinning, M. Bognitzki, W. Czado, Th. Frese, A. Schaper, M. Hellwig, M. Steinhart, A. Greiner, J. H. Wendorff, Adv. Mater. 13, 70 (2001).


F
igure 1: Porous polylactide fibers obtained by electrospinning from solution.


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Electrospinning of Biomaterials




G. L. Bowlin,1 J. A. Matthews,2 D. G. Simpson,3 E.-R. Kenawy,4 and G. E. Wnek4


Departments of 1Biomedical Engineering, 2Physiology, 3Anatomy, and 4Chemical Engineering

Virginia Commonwealth University

Richmond, Virginia 23284


One of the challenges to the field of tissue engineering/biomaterials is the design of ideal scaffolds/synthetic matrices that mimic the structure (mechanical aspects) and biological functions of natural extracellular matrix (ECM). The main purpose of the scaffold is mechanical support to allow for tissue regeneration while at the same time guiding (cell-matrix and cell-cell interactions; morphology guides structure of engineered tissue) cell differentiation and function (1). Some of the ideal scaffold requirements include biocompatibility, not inducing an undesirable host response, and being completely biodegradable while remaining non-toxic during replacement by cellular ECM components. Another challenge for the scaffolding is to be reproducibly produced in a variety of shapes and compositions (chemically and morphologically) with minimal time and cost. The technique of electrospinning (2,3) represents an exciting opportunity to meet these challenges by offering a simple approach to scaffold fabrication with controlled properties (4).


In electrospinning, polymer solutions or melts are deposited as fibrous mats rather than droplets, with advantage taken of chain entanglements in melts or at sufficiently high polymer concentrations in solution to produce continuous fibers. Of particular interest is the ability to generate polymer fibers of sub-micron dimensions, down to about 0.05 microns (50 nm), a size range that has been heretofore difficult to access yet one which is great interest for tissue engineering. Electrospinning is mechanistically similar to electrospraying, a key difference being that chain entanglements yield a fiber rather than droplets. Moreover, rather than break-up into very small droplets as is seen in electrospraying, entanglements lead to splaying of fibers into thinner ones, and herein is a particularly attractive aspect of electrospinning. The basic elements of a laboratory electrospraying or electrospinning system are simply a high voltage supply, collector (ground) electrode/mold, source electrode, and a solution or melt to be sprayed or spun. The sample is confined in any material formed into a nozzle with various tip bore diameters (such as a disposable pipette tip), with a very thin source electrode immersed in it. The collector can be a flat plate or wire mesh, or in more sophisticated modifications can be a rotating metal drum or plate on which the polymer is wound.


Experimental


Polymers electrospun included poly(lactic acid), poly(glycolic acid), poly(ethylene-co-vinyl acetate), and Type 1 collagen (rat tail). The electrospinning set-up consisted of a glass pipette, 0.32 mm diameter silver-coated copper wire (positive lead), various targets/molds with results presented from 303SS flat plates and 4 mm diameter mandrels, and a Spellman CZE1000R high voltage supply. Voltages in the range of 10-30 kV were employed. Scanning electron micrographs (SEMs) were recorded using a JSM-820 Scanning Microscope (JEOL, Ltd.). Smooth muscle cell seeding and proliferation was examined using SEM as well.


Results


All polymers studied were easily electrospun, producing mats with fiber diameters in the range of 0.1- 10 m. Poly(ethylene-co-vinyl acetate) was electrospun in the presence of tetracycline hydrochloride, and
Figure 2
the kinetics of release of the latter were studied. Particularly interesting is the electrospinning of Type I collagen, which produced scaffolds composed of polymerized collagen fibers with an average diameter of 0.1  0.04 microns (see Figure below). Transmission electron microscopy (TEM) evaluation shows a continuous 67 nm banding, indicative of natural collagen polymerization. A study of the use of these electrospun materials as tissue scaffolds is in progress.





References

1. D. J. Mooney and R. S. Langer, The Biomedical Engineering Handbook, CRC Press, (1995).

2. D. H. Reneker and I. Chun, Nanotechnology, 7, 216 (1996).

3. D. H. Reneker, A. L. Yarin, H. Fong and S. Koombhongse, J. Appl. Phys., 87, 4531

(2000).

4. J. D. Stitzel, K. Pawlowski, G. E. Wnek, D. G. Simpson and G. L. Bowlin, J.

Biomaterials Applications, in press.


Partial support by NASA Langley and the Whitaker Foundation is gratefully acknowledged.

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Nano-structured Electronspun Poly-D,L-lactide-co-glycolide Memberanes for Antiadhesion Applications

Dufei Fang, Xinhua Zong, Wander Chen, Sharon Cruz, Benjamin Hsiao* and Benjamin Chu*


Department of Chemistry

State University of New York at Stony Brook

Stony Brook, NY 11794-3400


An electrospinning method was used to fabricate bioabsorbable homopolymer poly-D,L-lactide-co-glycolide nanostructured membranes for biological and medical applications. The structure and morphology of the electrospun membranes have been investigated by using scanning electron microscopy. Both the fiber diameter and the nanostructure can be well controlled by tuning processing parameters such as solution viscosity and electric field strength. High quality polymeric membranes (~100 m thick) were produced with fiber diameters ranging from 100 to 1000 nm and a density of about 0.25 g/cm3, noting that the neat resin (PLA/PLG) has a density of 1.3 g/cm3. An extensive in-vitro study was carried out to evaluate the biodegradation performance of the eletrospun membranes including antibiotic drug loading capability of the membrane. The addition of antibiotics to the membrane with scheduled release profile could be used to reduce the risk of post-operative infections. An E. coli cell culture test was performed to verify the antibacterial effect of the drug containing membrane. Results showed that our membranes with a relatively high concentration of Mefoxin antibiotic drug could completely prohibit the growth of E. coli bacteria within 24 hours, when compared with the controlled samples. Finally, a series of animal (rat) tests based on established medical procedure models were performed and the results will also be presented.

_________________________

Work supported by the U.S. Army Research Office (ARO-DAAD 190010419)

And the Center for Biotechnology (X306R)


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The Relationship of Berry Number to the Diameter of PLA Fibers

Frank Ko , Baohua Han, Kinnari Chandriani, and Alan MacDiarmid*


Department of Materials Engineering

Drexel University, Philadelphia, PA 19104

*Chemistry Department

University of Pennsylvania, Philadelphia, PA 19104


Electrospinning is a unique process that produces continuous polymer fibers with diameters ranging over several orders of magnitude, from the micrometer range typical of conventional fibers, down to the nanometer range. Non-woven textiles composed of electrospun fibers have a large specific surface area and small pore size compared to commercial textiles, making them excellent candidates for use in filtration and membrane applications . In addition, the possibility of manipulating them into three-dimensional structures during deposition has implicated their use in biomedical applications such as scaffoldings for tissue growth While the process of electrospinning has been known for over half a century, current understanding of the process and those parameters, which influence the properties of the fibers produced from it, is very limited. With an interest to produce truely nanofibers , i.e. fibers with diameters less than 100 nm, this study is dedicated to the influence of polymer molecular conformation in solution, described by a dimensionless Berry number (Be) , on electrospinning of Poly(L-lactic acid) (PLA)/Chloroform system. It has been found that the degree of entanglement of polymer chains in solution can be described by Be . When the polymer is in a very dilute solution, polymer molecules are so far apart in the solution that individual molecules rarely touch each other and Be is less than unity. When the polymer concentration is increased, at some overlap concentration the individual molecules interact, from many contacts, and therefore become entangled; Be is then greater than unity. In this work, we compared and evaluated systematically the effects of Berry number on the morphology of electrospun nanofibers of two different molecular weights.

This study showed that he Barry number can be used to provide a quantitative link between fiber diameter and molecular conformation. Four regions of Berry Number were identified for the PLA in relation to fiber diameter and molecular conformation, thus establishing a processing window for the fabrication of nanoscale PLA fibers.


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In Search of Excellence in Textiles




Arun Pal Aneja


E. I. DuPont de Nemours & Company

DuPont Polyester Technology

Kinston, North Carolina 28501 USA


Twentieth century gave us an abundance of “miracle” fibers and polymers of every description. Textile scientists did not just imitate the products of nature, but improved on them. Success derived through imagination and innovation was based mainly on low-cost, petroleum-based feedstocks, efficient manufacturing schemes and consumer-driven functional characteristics of comfort and aesthetics.

What does the future hold and what must we achieve to sustain the impressive credentials of the past? The paper will deal with the components of excellence from a business, product and process perspective. A combination of tactical remedies, long-term business strategies, influence of globalization, and knowledge intensity will be the key business drivers. The future product and process discoveries will be built upon multi-disciplinary / synergistic technology platforms. As borders between material, biological and information sciences erode and become seamless, the areas where they interact or overlap will catalyze the reconceptualization of tomorrow’s textiles.


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Mechanical Characteristics of Cellulose filaments oxidized in nitrogen dioxide(IV) - carbon tetrachloride




Yurkshtovich N., Chechovski A., Golub N., Kosterova R.



Research institute of physical-chemical problems BSU, 220050, Minsk, str. Leningradskaja, 14


It is known, that under the effect of an nitrogen dioxide(IV) vary not only chemical, phisical-chemical, phisical-mechanical and biological properties of cellulose. Monocarboxylcellulose (MCC), received by an operation of an nitrogen dioxide(IV) on cellulose, acquires ability of the biodegradation in tissues of an organism.

The population of phisical-chemical, mechanical and biological properties (MCC) was by the basis of development on its basis of a surgical suture material. The broad introduction biodegradation of filaments because of MCC in surgical practice is hindered with poor mechanical strength, high speed of a biodegradation in an organism.

The purpose of the given work is the search of optimal conditions of carrying out of process of oxidation of the cotton and viscose filaments N2O4-CCl4, ensuring a minimum falling of their mechanical strength and optimal velocity of a biodegradation in an organism. The velocity of a biodegradation of oxidized cellulose filaments in tissues of an organism was evaluated on a velocity of loss of their mechanical strength in a phosphate buffered solution (pH=7,5) at the temperature of 310K. The influence of concentration of oxidant, time of oxidation, contents in cellulose filaments of carboxyl groups on an explosive load in a dry and wet kind, strength in a knot, relative elongation, stability in a phosphate buffered solution is investigated.

Is rotund, that by optimal concentrations of oxidant, for want of which one the minimum falling of an explosive load happens, for viscose filaments is 5-10 %, and for cotton - 20 % solutions. For want of optimal conditions of oxidation loss of strength of viscose filaments with the contents of carboxyl groups 3,2-7,2 % makes 7-38 %. The falling of an explosive load of cotton filaments with the contents of carboxyl groups 0,9-4,0 % more considerably also lies in an interval 25-63 %. By a method of radiography analysis is established, that the significant falling of strength of cotton filaments after oxidation is determined by their structural and chemical heterogeneity. Is found, that the stability of oxidized viscose filaments to an operation of a phosphate buffered solution (ph=7,5) in force degrees depends on conditions of carrying out of process of oxidation and contents in them of carboxyl groups. For want of oxidation of viscose filaments 5 % by solution N2O4 up to the contents in them 3,5 % of carboxyl groups the loss of strength for 10 days of a storage in a buffered solution makes 42 %. Oxidation of filaments in more strong solutions N2O4, and also large rate of oxidation reduce stability of filaments to a phosphate buffered solution sharply. Is established, that as much as possible come nearer of the viscose filament with the contents of carboxyl groups to the standard physics of mechanical performances of a suture material 1,5-2,3 %, with an explosive load 16,4-18,9sN/mm2 and loss 55 % of strength on a comparison with an initial not oxidized filament for 14 day of a storage in a buffered solution.


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Effect of Electrospinning Material and Conditions upon Residual Electrostatic Charge of Polymer nanofibers




Peter P. Tsai & Heidi L. Schreuder-Gibson


University of Tennessee, Knoxville, TN 37996-1950

U.S. Army Natick Soldier Center

AMSSB-RSS-MS(N)

Natick, MA 10760-5020


Permanent electrostatic charge can be embedded into insulating fibers. Two methods of fiber charging result in the production of “electrets,” or a separation of charges within the fiber mat. Triboelectrification results from induced charge by mechanical perturbation of two fiber types of dissimilar electronegativity. Corona charging of insulating fibers such as polypropylene is easy to implement as a web post treatment, but results in lower charging of the mat than triboelectrification. Electrospinning has been investigated as a method of producing higher surface area webs for improved filtration efficiency, and as a method to produce charged fibers during fiber formation for use in filtration media. Four polymers have been evaluated for their charge induction and charge retention characteristics and are ranked according to their inherent polarity: polyethylene oxide, polycaprolactone (a polyester), polycarbonate, and polystyrene. Electrical properties for the resulting fibers from these polymers are described, including inherent charge by either induction or embedment, charge density, charge distribution, and the decay rate. The contribution of these charges to filtration performance and the possible applications of charged nanofiber webs is discussed.


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Extrusion and Analysis of Nylon/Montmorillonite Nanocomposite Filaments




Marian G. McCord, Suzanne N. Rodden, Samuel M. Hudson


College of Textiles, North Carolina State University


The morphology and mechanical properties of extruded nylon-clay nanocomposite filaments were compared to those of neat nylon samples. Mechanical properties were then compared to those of films cast from the same materials. Recent studies on nylon-clay nanocomposite films have demonstrated improvements in strength and modulus upon addition of the filler [ref]. While the nylon 12-2 % clay nanocomposite filaments showed a slight improvement in modulus, both the nylon 6-5 % clay nanocomposite filaments and the nylon 12-2 % clay nanocomposite filaments exhibited significantly lower tenacity measurements and higher average breaking strains than their neat counterparts. Nylon-clay nanocomposites crystallized at a higher temperature and had a lower percent crystallinity than the neat samples. Microscopic analysis of the filaments revealed that the nylon 6-5 % clay nanocomposite filaments had unusual surface striations as well as irregular cross-sections. Nanocomposite and neat nylon 6 films were then cast from formic acid and mechanically tested. The nanocomposite films exhibited significantly higher breaking stresses than the neat films. Burn tests conducted on the filament and film samples showed that the nanocomposites had enhanced char properties as demonstrated by the black, carbon-silicate residue remaining after the flame was extinguished.


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Cellulosic Nanofiber Membranes for Liquid Wetting/Absorbency and Chemical Reactitivity




Haiqing Liu & You-Lo Hsieh


Fiber and Polymer Science

University of California, Davis, CA 95616-8722


Nanofiber membranes of several cellulose derivatives are produced by electrospinning. The effects of solvent systems and electrospinning conditions on fiber size, fiber morphology and membrane pore structure have been investigated. Further reactions of the cellulose derivatives have been demonstrated to produce highly thermally stable and biodegradable microporous membranes. The ultra-high surface-to-volume ratio and highly amorphous characteristic of these membranes make them excellent substrates for further conversion to carry various chemically reactive functionalities. Liquid wetting behavior as well as absorbent properties of these menbranes are related to their chemical and physical characteristics.


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