reactive materials research for self-detoxifying cb ... · u.s. army research, development &...

U.S. Army Research, Development & Engineering Command Natick Soldier Center, • Natick, MA

Reactive Materials Research for Self-Detoxifying

CB Protective Clothing

Heidi Schreuder-GibsonU.S. Army Natick Soldier Center

Natick, MA


Concept

HD Catalyst

Poly(vinyl)amines

O

HO OH

H2COCH2

O

NN

O

O

CH3CH3

Cl

n

CHLORAMINEBactericide, Agent Decon

Place reactive materials in fabrics that detoxifyContaminants on clothing within hours of exposure.

CH2 CH CH

OH NH2m n

CH2

ModifiedCyclodextrins


ApproachChloramides & Quats -Shell Fabric

Sporicide and Agent Decon, Water RepellancyPOM Catalysts – Liner Materials

Carbon SurfacesPolymer Film Surfaces

Nanoparticles – Attached to Fabrics, Blended into FibersParticulate Absorbants

Reactive Permselective Membranes - Liners

Bio, HD, VX

HD

HD, VX

G, VX


NanoparticleReaction Rate Studies

Depletion of 2-CEES- In Solution- In Vapor


Comparison of Old and New POMs

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 5 10 15 20 25 30

Exposure Time (hours)

CEE

S R

emai

ning

(mg)

TiO2New POM

Solution Depletion of 2-CEESNanoparticle TiO2 vs POM Catalyst

Very reactive catalyst


Equilibrium Vapor Adsorption Measurements

% CEES ADSORBANT Vapor Uptake

Carbon Spheres 56NanoAl2O3 - PLUS 99NanoAl2O3 10NanoTiO2 17


Thermal Desorption GC/MSSample in Tube


NanoA

lumina

PLUS

Shell

Shell+Chlo

ramide

Shell+Nan

o/Chlo

ramide

Diethyl sulfide

Ethyl vinyl SulfideCEES Oxide

Ethylthio ethanolCEES

0

20000000

40000000

60000000

80000000

100000000

120000000

140000000

160000000

180000000

Mas

s Sp

ec (C

ount

s)

Depletion of CEESFormation of Products

(CEES-OH)(CEES=O)

Oxidation

Dehalogenation


0.50 1.00 1.50 2.00 2.50 3.00 3.500

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

110000

120000

130000

140000

150000

Time-->

2.12

2.24

3.06

CH2-CH2S

CH2-CH2Thiirane

SO2

ChloroethyleneCl-CH=CH2

Some Products from Oxidation Reactions of 2-CEES

Cyclization


NMR (HRMAS) Sample preparation

Vapor chamber for exposing catalyst to vaporous agent/simulant

SAMPLE

4 mm HRMAS rotor for examining small volumes of sample (< 100 µl)


1H 1D Spectra Reaction Kinetics

4.5 hrs

24.6 hrs

10.4 hrs

27.8 hrs

63.3 hrs

71.4 hrs

94.8 hrs

CEES Peaks at 2.8 and 2.6 disappear upon vapor exposure to nano-Al2O3

2.8 2.6


Normalized 2-CEES Degradation KineticsBy Solid State NMR

0

20

40

60

80

100

0 10 20 30 40 50 60 70 80 90 100

Time (hrs)

% C

EES

Rem

aini

n

Alumina

Alumina Plus

Titania


Rate of CEES Vapor Depletion in HRMAS NMR Studies

Rate Activity% CEES/hr mgCEES/24hr

mgNanoparticleNanoAl2O3 0.83 0.020NanoTiO2 2.3 0.094NanoAl2O3-PLUS 3.1 0.74*

*30 g/m2 of nanoAl2O3-PLUS needed to meet current protection requirements. 100 g/m2 of nanoTiO2

needed.


POM Catalyst Reactionswith 2-CEES

- POM on Carbon Surface- Effect of Copper Content


0 POM POM POM1Cu

POM2Cu

POM5Cu

POM10Cu

Diethyl sulfideEthyl vinyl Sulfide

CEES OxideEthylthio ethanol

CEES

0

2000000

4000000

6000000

8000000

10000000

12000000

14000000

16000000

18000000

Mas

s Sp

ec (C

ount

s)POM/Carbon Reduces 2-CEES

in GC/MS

New Reaction Products Found


Reaction Product from Carbon/POM + 2-CEES

Isopropanol+Water Isopropanol


Dimer of 2-CEES from Oxidation Reaction

SS+

Cl-

OH

Dimerization


CEES Vapor Diffusion Studies

Thick vs Thin SupportedSelectively Permeable Films

ReactivePVAM (polyvinyl amine-co-vinyl alcohol)

Non-ReactiveNafion, Membrane C, Membrane T


Reactive SelectivelyPermeable Membranes

CH2 CH CH

OH NH2m n

CH2Polyvinyl alcohol-co-amine, PVA-Am

PVA-Am Film

After DFP VaporExposure

PVA-Am Film Hydrolyzes DFP, G-agent Simulant

(Seen by pH indicator).


0

300

600

900

1200

1500

0 0.2 0.4 0.6 0.8 1.0

Polyvinyl Alcohol / Polyvinyl Amine Copolymer(PVA-Am)

PVA-Am M6

PVA-Am M12

PVA-Am L12

PVA-Am L6Nafion (140 µm)

Expanded Polytetrafluorethylene (ePTFE)

Gore-Tex Laminate

Mean Relative Humidity

Wat

er V

apor

Diff

usio

n R

esis

tanc

e (s

/m)

High

Water VaporDiffusion Resistance

Low

(Worst)

(Best)

Water Vapor Diffusion(Thin, Supported)

(Thick)

(Thick)

(Thick)

(Thick)

(Thick)


12

Gore-Tex

MembraneT

MembraneC

M12

Nafion

0

2000

4000

6000

8000

10000

12000

14000W

ater

Vap

or F

lux

at 5

0% R

H (g

/m2/

da

Number of Film Layers

Water Vapor Flux of Supported Membranes

Water Vapor DiffusionThin, Supported Films


CEES Vapor DiffusionThin, Supported Films

3mg CEESapplied

Weatherpr

oof M

embNafi

on 1-La

yer

Nafion

3-Laye

rMem

brane T

Membran

e CM12

1-Laye

rM12

2-Laye

r

80RH50RH

0RH0

10

20

30

40

50

60

70

CEE

S Va

por P

enet

ratio

n (%

) .

80RH50RH

0RH


Conclusions

Chloramide-treated fabrics break down 2-CEES in solution and in vapor challenge tests.

One of the major by-products was the nontoxic sulfoxide. Other by-products include dimers.

Chloramides bound to nanoparticles of alumina were reactive, but not as active as the chloramides alone.


NanoAl2O3-PLUS more adsorptive than activated carbon.

NMR found that NanoAl2O3-PLUS depleted 2-CEES at a rate of 0.74 mgCEES/mgNanoparticle/day.

A fabric weight of 1-33 grams per square meter of NanoAl2O3-PLUS needed to meet the 1mg/cm2/day protection requirement for clothing systems.

100 gsm of nanoTiO2 would be needed for protective fabrics to meet Chemical Protection requirements.

Conclusions


Conclusions

Carbon-bound POMs faster than free POM in the decomposition of 2-CEES.

Carbon-bound POMs can be optimized with Cu to increase depletion of 2-CEES by 7x.

Copper-containing POMs completely neutralize 2-CEES in 30 min. Produce CEES-oxide (sulfoxide) product.


Conclusions

Thin supported PVAM films have high water vapor permeation, similar to commerical permselectivemembranes C and T.

Thin supported Nafion has the highest water vapor permeation.

Thin supported Nafion and MembraneC allow CEES penetration above 50RH

Thin supported PVAM films and MembraneT block CEES below 80RH.


Reactive Fabric System Design

SHELL

QuaternaryAmine on TopSporicide Water-Repellent

ChloramideUnderneathBio, HD & VX

Reactive Permselective Liner

Nanoparticle “sandwich”

Carbon-Nylon Tricot Knit Scrim


AcknowledgementsProfessor Craig Hill and Dr. Nelya Okun, Emory

University for POM Catalysts

Gentex Corporation for spherical carbon

Reactive Materials Team at Tyndall AFBFor Chloramides & Test Data

Edgewood NMR Group for MAS Results

Erkol, Ltd. for PVAM Polymers

Phil Gibson, Joel Carlson, John Walker at Natick

reactive materials research for self-detoxifying cb ... · u.s. army research, development &...

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