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Using nano particles in protective clothing
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Serving Customer Needs Through Advanced Chemistrywww.NanoScaleCorp.com
ACS Spring 2010 National Meeting and Exposition, March 22, 2010
Shyamala Rajagopalan, Ph.D.Manager, Research & Project Development
NanoScale Corporation, Manhattan, KS
From Nanoparticles to Novel Protective Garments
Sponsored by : NIOSH
Phase II SBIR: Grant No. 2R44OH007963-02A2
Serving Customer Needs Through Advanced Chemistry
• Goal of the Project• Current Technology and Its
Limitations• Project Work Plan• Project Progress• Acknowledgements
Presentation Outline
carbon vs nano
Serving Customer Needs Through Advanced Chemistry
Project Goal and Envisioned Product
• Protective
• Lightweight
• Air-permeable
• Comfortable
Prepare and test materials for clothing to protect against chemical
hazards.
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Available Technology• Impermeable materials.
Generally made of rubber or neoprene or other elastomers Heavy and bulky Hot due to lack of air and water vapor permeability Uncomfortable to wear Ex: OSHA approved Level A suit
• Air-permeable materials. Shell fabric; a layer of sorptive material; a liner fabric Low physical burden High water vapor permeability Protection can be low in some instances Ex: JSLIST suit
• Semi-permeable materials. Porous and solution-diffusion membranes Ex: Gore-Tex
• Selectively permeable materials. Thin, lightweight, layered, and flexible Ex: US Army NSC; Gore-Tex; DuPont
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Current Technology - Limitations• Protective textiles based on carbon
materials need REAL enhancement.• Only PARTIAL PROTECTION is
afforded by activated carbon through physical entrapment of toxins.
• Activated carbon DOES NOT NEUTRALIZE adsorbed chemicals; it simply stores them.
• Preferential adsorption of water by carbons or increase in temperature results in OFF-GASSING of adsorbed toxins.
• Untreated carbon has LITTLE EFFECT UPON ACID OR ALKALINE GASES.
Targeted Laminate Properties
• Weight reduction is targeted to come from the fabric/adhesive.
• Effect of sorbent on the textile’s air permeability is unknown.
• Sorbent immobilization protocol on the textile will also play a critical role in the laminate’s properties.
Serving Customer Needs Through Advanced Chemistry
PropertyCarbon
Bead Laminate
NanoScale Proposed Laminate
Total weight (g/m2) 402 350
Sorbent:Fabric weight (g) 250:152 250:100
Air Permeability (cm3/cm2.s)
63 >63
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Project Work PlanTask 1Preparation of granulated mixed nanoparticlesMonth 1 - Month 4
Task 2Performance evaluation and down selectionMonth 1 - Month 5
Task 3Textile/nanoparticle integrationMonth 3 - Month 11
Task 4Permeation testingMonth 6 - Month 12
Task 6Prototype productionMonth 18 - Month 24
Task 5Scale-up studiesMonth 13 - Month 17
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Air Filtration Test Apparatus
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Compressed Air
Water
SorbentTest Bed
FT-IR w/16 m Gas Cell
Challenge
Agent
Vent to
Hood
Humidity Controller
• Goal is to screen sorbents for initial downselection.
• Challenge and breakthrough concentrations are based on OSHA PEL/IDLH.
Breakthrough Test Results
• Breakthrough time in minutes. • Average of 3 trials.• Single metal oxides.• Bi-metal oxides.• Tri-metal oxides.
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Sample NH3 HCN 2-CEES Sample NH3 HCN 2-CEES
1 5.5 17 21 8 5.5 54 19
2 6.9 20 32 9 7.3 25 24
3 7.3 71 29 10 5.0 12 23
4 5.5 1.0 12 11 43 6.5 61
5 7.3 52 41 12 34 22 36
6 3.0 >180 3.0 13 27 30 38
7 6.5 49 28 14 21 45 34
Commercial 31 6.0 29
Downselected Formulation• One nano material formulation was
downselected and optimized based on breakthrough test results.
• Granules based on downselected formulation have ≥70% Ball Pan Hardness.
• No binders were required to harden the granules.
• Used granule sizes: -60+120, -60+80 and -40+60 mesh.
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Health Effects and Safety• Acute toxicology testing done at the U.S. Army’s Center for Health
Promotion and Preventative Medicine (USACHPPM) under GLP.– NanoActive materials are no more toxic than their commercial
counterparts Several materials have been tested.– Sub-chronic toxicology testing showed no detrimental effects (FAST-
ACT).• Human immune cell testing by Prof. Paul Wright, Toxicology Unit,
School of Medical Sciences RMIT in Melbourne, Australia.– No cytotoxicity to human immune cells in this study (FAST-ACT).
• Dermal penetration study by Dr. Deon van der Merwe, Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS.– No penetration of intact human skin (FAST-ACT).
• Lung effect study by Dr. John Pickrell, Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS.– No lasting detrimental effects (FAST-ACT).
Serving Customer Needs Through Advanced Chemistry
Serving Customer Needs Through Advanced Chemistry
Permeation Set Up – Initial Test
Vessel + Comfort Layer
Vessel + Comfort Layer + Sorbent
Vessel + Comfort Layer + Sorbent + Black Liner +
Cover Fabric
Vessel + Comfort Layer + Sorbent + Black Liner
Complete Permeation Test Set Up
• For DMMP testing: Water in inner vessel.
• For 2-CEES testing: Carbon beads in inner vessel and water in outer jar.
Laminated Carbon Fabric -Key Points
• A single layer of carbon beads is glued between black silk and comfort layers.
• Adhesive Web Glue Sheet is used in the gluing of the carbon beads.
• Fabric is stiff.
• Fabric is slightly breathable.
• Adhesive Web Glue Sheet also helps to contain the contaminant.
• No agent permeation was seen.
• No agent was seen on the cover fabric.
• Solvent extraction showed intact agents from the laminate.
Serving Customer Needs Through Advanced Chemistry
Sample2-CEES,
%DMMP, %
Permeated 0 0
Extracted from the laminate
100 97
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ASTM F739:Fabric Permeation Testing• ASTM F739 is designed to measure the permeation of liquids or gases under
conditions of continuous contact: Liquid agents are tested in the closed top/open loop configuration. Gaseous agents are tested in the open top/open loop configuration.
Serving Customer Needs Through Advanced Chemistry
NFPA Standard Testing Conditions• Liquid agent.
Chamber temperature at 32˚ C (±3˚ C). Relative humidity of 80% (±5%). Collection gas flow at 1 LPM.
• Gaseous agents are tested under the same conditions with the gas flowing at 1 LPM through the challenge side.
• Tests are run for 1h.• Select fabric samples were further extracted for retained
chemicals and byproducts.
Liquid2 CEES (HD simulant)
DMMP (GD simulant)
GasHCN
NH3
Reactive Liner - 2- LayersKey Points:• Granules were well immobilized.• No shedding was observed.
Challenges:• Weighs 442 g/m2. • Stiff.• Air permeability: 6.12 cm3/cm2.s.• Did not meet requirements of a Class 2 Protective
Garment.
Interfacing I
Adhesive Sheet A
Nano Material
Adhesive Sheet A
Interfacing I
Heat Bond Fleece
Nano Material
Heat Bond Fleece
Key Points:• Weighs 338 g/m2.• Air permeation: 57 cm3/cm2.s.• Granules were well immobilized.• No shedding was observed.• More flexible.• Passed permeation tests as Class 2 protective
garment.Challenges:• Problems with locating the same fabric. • Little stiffer than the carbon bead laminate.
Serving Customer Needs Through Advanced Chemistry
2nd Reactive Liner
1st Reactive Liner
Reactive Liner – 3 - LayersKey Points:• Laminate weighs 377 g/m2.• Air permeability 71.9 cm3/cm2/s.• Passes Class 2 Protective Garment requirements.Challenges:• Laminate weight.• Mobile granules. • Granules are smaller than the pore size of the
interfacing.• Shedding is an issue.• Manufacturability of a 3-layer configuration.
Interfacing I
Nano Material
Fleece 1 with Spray Adhesive D on both sides
Nano Material
Interfacing I
Interfacing I
Nano Material & Powder Adhesive B
Fleece 1
Nano Material & Powder Adhesive B
Interfacing I
Key Points: • Weight: 387 g/m2
• Air Permeability: 73 cm3/cm2/s.• Granules fairly well secured, very minimal
shedding. • Passes as a Class 2 protective garment.
Challenges:• Laminate weight.• Manufacturability of a 3-layer configuration.
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1st Reactive Liner
2nd Reactive Liner
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Products from Agent Chemisorption
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Permeation Test Samples from 2-CEES Experiments
Samples(% Extracted)
2-CEES (% Permeated)
2-CEES EVS HEES
Non-Laminated carbonTextile (commercial) <1 0 0
4.7Sorbent 85 0 0
Non-Laminated Nano sorbent
Textile (commercial) 0 0 046
Sorbent <1 <1 4
Laminated carbon Textile (commercial) 92 0 0 6.1
Laminated carbon Textile (NanoScale) 86 0 0 0
Laminated Nano sorbent Textile (NanoScale) <1 <1 27 1.4
Protocol • Loose sorbent was separated from textile and extracted with ethyl ether .• Separated textile was extracted with ethyl ether .• Laminated swatch containing sorbent was extracted as whole with ethyl ether .• All samples were analyzed by GC-FPD.
Outcome
Conclusions• Commercial textile (non-laminated) did not trap any 2-CEES or by-products.
• Textile (Commercial & NanoScale) containing carbons only physisorbs 2-CEES.
• NanoActive material containing swatch provided the least amount of extractable 2-CEES.
• Lamination is critical to reduce permeation.
• Destructive adsorption by nano materials was confirmed .
Serving Customer Needs Through Advanced Chemistry
Permeation Test Samples from DMMP Experiments
Samples DMMP (% Extracted)
DMMP (% Permeated)
Laminated control (no sorbent) Textile (Commercial)
10 69
Laminated control (no sorbent) Textile (NanoScale)
7 54
Laminated carbon Textile (Commercial) 85 0
Laminated carbon Textile (NanoScale) 78 0
Laminated Nano sorbent Textile (NanoScale) 20 0
Protocol
• Laminated control was extracted with ethyl ether.
• Laminated swatch containing sorbent was extracted with ethyl ether.
• All samples were analyzed by GC-FPD.
Outcome
Conclusions• Laminated textile controls (no sorbent) contained low amounts of extractable DMMP with high
permeation.• Carbon containing textile swatches yielded large amount of extractable DMMP with low permeation.• NanoActive material containing textile swatches yielded the least amount of extractable DMMP with
low permeation. • By-product characterization is in progress.• Agent exposure threat is lower with nano materials containing textiles.
Attestation of Agent - Sorbent Interaction
Agent SorbentTemperature Range
(onset to conclusion,°C)
2-CEESCarbon 179-345
NanoScale sorbent 270-360
DMMPCarbon 170-320
NanoScale sorbent 285-370
Protocol• Carbon and nano formulation were challenged against CWA simulants 2-CEES and
DMMP.
• Samples were analyzed using TGA up to 600°C (10°C/min heating rate).
• Temperature at which agent off-gassing from sorbent was recorded as reflection of binding strength.
Conclusions:
NanoScale sorbent exhibited higher binding strength than carbon for 2-CEES and DMMP as reflected by higher onset and conclusion temperatures.
Serving Customer Needs Through Advanced Chemistry
Where are We Now?
• Defining overall product concept/clothing system (classification by design, performance, and service life etc.).
• Defining market needs and identification of user needs (fire fighters, first responders, war fighters, drug raid, agriculture workers, chemical labs etc.).
• Performance and cost.
Serving Customer Needs Through Advanced Chemistry
PropertyCarbon Bead
Laminate
Reactive Liner-2-Layer
Reactive Liner-3-Layer
NanoScale
Proposed Fabric
Total Weight (g/m2) 402 338 387 350
Sorbent:Fabric Weight (g)
250:152 250:88 250:137 250:100
Air Permeability (cm3/cm2.s)
63 57 73 >63
Serving Customer Needs Through Advanced Chemistry
Acknowledgements
Team Members at NanoScale Corp.Chris Aikens
Shuvo Alam
Dennis Karote
Jane Langemeier
Cherry Leaym
Justin Millette
NIH/CDC/NIOSH
Fabric Suppliers
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