Nanofibers: Current Status and Role on Future of Technical

Textiles

Gajanan BhatProfessor MSE & Director, UTNRL

University of Tennessee, Knoxville, TN, USAgbhat@utk.edu

TECHNOTEX 2011, Mumbai, IndiaAugust 26, 2011

Nanotechnology

“ The science, engineering and technology related to the understanding and control of matter at the scale length of approximately 1 to 100 nanometers. However, nanotechnology is not merely working with matter at the nanoscale, but also research and development of materials, devices and systems that have novel properties and functions due to their nanoscale dimensions and components”

The National Nanotechnology initiative at Five years: Assessment and Recommendations of the National Nanotechnology Advisory Panel, Presidents Council of Advisors on Science and Technology, Washington, DC, May 2005, p7.

Has not reached the state of application that draws public interest

Can be a big investment - a lot at stakeLot of research and developmental activity in this area

In general technology lags behind science

Textiles – technology may be ahead of science

Nanotechnology

Nanotechnology

Relevance to TextilesNanofibersCoatingFinishingModificationCharacterization

Nanofibers

DiameterHigh specific surface areaHigher filtration efficiency

Nanofiber Research Publications

Cotton Structure – Nanofibers?

Wool Structure – Nanofibers?

Production Techniques for Nanofibers

Splitting (IS)DrawingElectrospinningForcespinningModified Melt Blowing (MB)

Production Techniques for Nanofibers

Splitting of bi-/multi-component fibersFrom multicomponent spinning and dissolution of some components

Hard to precisely control the fiber dimensions

Solvent

Electrospinning Process

Simple process at lab scaleFine fibers possible

ScalabilitySolventsDielectric requirementsNot suitable for PP

Forcespinning Fiberrio

By using Centrifugal ForceBoth solutions and MeltsNo high voltage, no hot airNew Process – many unknowns

Melt Blowing Process

Fiber Diameter (2-5 μ)Air permeability/HydroheadFiltration efficiencyPorosity, pore size & DistributionMechanical PropertiesComposite structuresSuitable for any thermoplastic polymer – No solvents

Nanofiber Melt Blowing

Figure 6: Nanofiber Melt Blowing

Nanofiber Melt Blowing

Modular Dies AGR/NTIHills

Melt Blown Nanofibers

Melt Blown Nanofibers

20-inch Meltblowing Line

Melt blown Nano and Sub-Micron Fibers

Where are We?

Consistently produce NF MB webs from several thermoplastic polymersNarrow fiber diameter distributionOptimize Processing ConditionsUnderstand the Morphology Development

Evaluating Composite Structures

Applications of Melt Blown Nanofibers

Applications of Melt Blown Nanofibers

ScaffoldsControlled Rate of Drug DeliveryTissue engineeringWound dressing

Applications of Melt Blown Nanofibers

Detoxification/Decontamination,Enhanced reactivity of the Catalysts, Biocides,Enhanced oxidative/ hydrolyzing activity of Catalysts (nano MgO, -Cyclodextrin), biocides

(N-Halamines), have against wide spectrum of of CBWA Polymer

nanofiber membrane to capture chemical agents

Applications of Melt Blown Nanofibers

Figure 10: Functionalized nanofibers for protective clothing

Applications of Melt Blown Nanofibers

Nanocomposites

Oil AdsorbentsAccidental oil spillsFuel cell membranes, battery and fuel cell separators, catalysis

Applications of Melt Blown Nanofibers

Filtration MediaLower pressure drop Higher permeability Higher particle capture efficiencyQuality factor

Air & water purification filters, chemical filtration, HEPA filtration devices, face masks, filters for furnace

Applications of Melt Blown Nanofibers

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Nanofiber Arrays Dramatically Boost Battery Energy StorageNew method allows a dramatic boost in capacity for a given weight

http://www.nano.org.uk/news/1571/

Future Prospects of Melt Blown Nanofibers

Future ProspectsThe global market should reach $176 million in 2012 and grow to $825 million by 2017

$1 trillion are market in textile$100 billion market in electronic packaging Scaffolds for the $10 billion tissue engineering by 2020

The mechanical/chemical sector is projected to account for 73.5% of total revenues in 2007

Nanofiber Market ProjectionBCC Research

Nanotechnology for Textiles

Nanocomposite fibersCNT and nanoclay

FinishesWater repellencyUV protectionAntibacterialWrinkle resistanceReactivity

Functionality without sacrificing physical properties

Nanotechnology for Textiles BASF

Nanoparticle Application on Textiles

Continuous Spraying systemSonication to achieve dispersion of nanoparticles

Uniform application on nonwovens and other textiles

Other Nonwoven Related Research Projects at UTNRL

Nanoparticle Reinforced Fibers, Webs and Films (Corp)Nanoparticle Reinforced Composites (ONR)Thermal Bonding FundamentalsMelt Blowing –Processing, Polymers and FundamentalsNanofiber CompositesBiodegradable Nonwovens & CompositesCoating of textiles, webs and filmsMultifunctional Composites –(NASA)Flame Retardant Nonwovens – (USDA & Cotton Inc.)High Temperature Polymeric Fibers – (Corp)Fiber Formation Fundamentals – (corp)Other Proprietary work – Various companies.

Future of Nanotechnology for Textiles in Indian Context

Availability of Science and TechnologyProduct DevelopmentValue AdditionMarketing

Approach Domestic and Global

Creativity and Engineering will lead to tremendous growth

– where do you want to be?

Thank YouThank You