Advances in etched ion-track polymer membranes for environmental and

microelectronic applications

Marie-Claude DUBOIS-CLOCHARDLaboratoire des Solides Irradiés

CEA2/CNRS/Ecole Polytechnique

FRANCE

Laboratoire des solides Irradiés

Mixt laboratory : CEA - Ecole Polytechnique – CNRS, UMR 7642Management: Kees Van Der Beek90 staff members – 6 teams among them XPnano : 8 permanent researchers

The site: the « Ecole Polytechnique » Engineer School

Plateau de Saclay (5km from CEA-Saclay site)

EB facility2,5MeV

PVDF + copo, ETFE, PTFE + terpo

Solid Polymers: films, fibers, nanoparticles…

Ionizing radiations

Film structure, physico-

chemical properties

PUR PP, PE PET PC

Unsaturated bonds, radicals, oxidation

Crosslinking and scission, radiolysis gases

GANIL

LSI

Swift Heavy Ions

Electrons

gamma CEA LIDyL

X, UV USTL

plasmas Faculté de Pharmacie

Irradiation Effects Radiografting

sterilization

ageing stabilityradiolysis

Functionnalization

nanostructuration

Track etching

new

Materials

Irradiated polymers

Research Fields

Energy Environment/HealthNanoelectronic

Fuel cellCancer

Capteurs de pressionA

Fuel cell

Tracks formation

Ion-matter interaction : Energy loss

nm

keV

dx

dE

Deposited Energy per charged particle and per length unit

(dE/dx)Total=(dE/dx)nuclear+(dE/dx)electronic

≈1MeV/u

Nuclear collisions

(dE/dx)nuclear

Electronic interactions

(dE/dx)electronic

Log(Ion-projectile energy)

Log(d

E/d

x)

Tracks

≈1keV/u

Ion-matter interaction

Tracks at the surface of some solids

High sensitivity Weak sensitivity

dE/dxthreshold

~1 keV/uma ~20 keV/uma ~50 keV/uma

Insulators

Polymers

Oxydes

Spinels

Semi-conductors

Amorphous Si

GeS, InP, Si1-xGex

Si, Ge

Metals

Amorphous alloys

Fe, Bi, Ti, Co, Zr

Au, Cu, Ag …

Defaults in a latent track in a polymer film

- Chain scission- Amorphization- Gaz formation (COn, CnHn,…)- Radical formation- Cross-linking- Multiple bonds (ex. C=C, C≡C)

Steckenreiter et al, J. Polym. Sci. A37 (1999) 4318

Kr(720MeV) Kapton

C≡C versus fluence

Irradiation Latent Tracks

Vacuum, O2,

N2, SO2, NH3…

Grafting

monomer

+ T°

Radio-grafting in latent tracks

Natacha BETZ « Ion-Track Grafting » NIM B 105 (1995) 55-62

Natacha Betz

M-C. Clochard, T. Berthelot, C. Baudin, « Procédé d’élaboration de Membranes Conductrices de Protons de Pile à Combustible par Radiogreffage » CEA French patent (BD 1727) FR 0757875 ext PCT WO/2008/062726 (2007)

T. Berthelot, M-C Clochard, « Membranes Conductrices de Protons pour Pile à Combustibles présentant un gradient de protons et Procédés de

Préparation desdites Membranes» CEA French patent (BD 10047) FR 0757873 ext PCT WO/2009/103925 (2007)

T. Berthelot, M-C Clochard, « Membranes Conductrices de Protons pour Pile à Combustible et Procédés de Préparation desdites Membranes» BD11266 French patent FR0955854 ext PCT WO/2010/062512 (2009)

E. Gallino, M-C Clochard, A. Morin, G. Gebel, "Suspension aqueuse comprenant des particules de catalyseur métallique et des particules de polymère

spécifique utilisable pour la fabrication de couche active d'électrode" CEA-X-CNRS FR1252533 (2012)

5 patents

Application to Polymer Electrolyte Membrane for fuel cell

A B CA B C

(A) PEMFC for automotive (ex: GENEPAC PSA-CEA), (B) Stack and (C) single cell.

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000

Nafion 80°C 4 bar, 100% RH80°C 4 bar, 100% RH80°C 2 bar, 100% RH70°C 2 bar, 15% RH

Cell

vo

lta

ge /

mV

Current density / mA.cm-2

61 mS.cm-1 ; 1,2 A.cm-2

Identical efficiency as Nafion

Ion-track membranes for fuel cell: creation of proton conductive channels

Perspectives: how improving the membrane-electrode interface ?

• On-going research

– Understanding exchanges in active phases in the MEAs

– Electrochemical cell adapted for TEM in situ

(Nan’eau PROJECT)Phys. Chem. Phys., 2013, 15, 11236—11247

Commercial ink Ink containing radiografted PVDF NPs

Gamma irradiation

M M

MM

MM

M

PVDF nanoparticles

Covered with ionomer

functionalisation

purification

Gamma irradiation

M M

MM

MM

M

PVDF nanoparticles

Covered with ionomer

functionalisation

purification

-25

-20

-15

-10

-5

0

5

10

3200 3300 3400 3500 3600 3700

Electrons (100 kGy)Rayons gamma (10 kGy)

Inte

nsité n

orm

alisée

par

la m

asse

Champ (Gauss)

-6

-4

-2

0

2

4

6

3200 3300 3400 3500 3600 3700

Electrons (100 kGy)Rayons gamma (10 kGy)

Inte

nsité n

orm

alisée

par

la m

asse

Champ (Gauss)

Alkyl radicals under vaccuum

O2

R

ROO

Irradiations

g

PVDF +

monomer

Irradiations + grafting

Other monomers of interest: vinyl imidazole doped phosphoric acid for high T°C fuel cell applications

In-situ radiografting

monomer

Track revealing : track-etching

Track etching

Template synthesis

PPy nanotubesCylindrical and conical metallic nanowires

Template synthesis: Nanoelectronics - spintronics

Biziere, Nicolas; Gatel, Christophe; Lassalle-Balier, Rémy; Clochard, Marie-Claude;Wegrowe, Jean-Eric; Snoeck, Etienne "Imaging the fine structure of a magneticdomain wall in a Ni nano-cylinder » Nanoletters (2013)

TEM magnetic holography

For the first time, we have imaged2 head-to-head magnetic walldomains on single nanowire. Thisresult have been confirmed parcalculation.

Challenge for MRAM

Controlling magnetic domain wallplaying on the nanowire geometry

Pressure sensor(G. Melilli)

P.Do Chung et al., MRX (2014)

A B

C D

1 µm

500 nm

Gold patternPVDF

Fine gold layer on the bottom

1,5 mm

500 nm

Thick gold layer on the top coveringthe etchedtracks

resin

Tracks in PVDFz plan

Track etched PVDFxy plan

z

xy

Developed at GSI (Germany)

Commercial products (Nuclepore, Poretics) Millipore®, Whatman®…

Ions species: C… Xe… U Fluence: 1…1013ions/cm2

1srt application: membranes for filtration

Membrane recent developments:fabrication on hybrid membranes based on nanoporous graphene

Characterization of nanoporous graphene-on-PMMA substrate

Graphene sidePMMA side

Graphene side profile

Graphene side

PMMA side

-1,0 -0,5 0,0 0,5 1,0-4

-3

-2

-1

0

1

2

3

4

U(m

V)

I(A)

R=3126

Gold contact 2

Goldcontact 1

NPG-on-PMMA membrane

SiO2

Electrical behaviour

magnetoresistance

Perspectives: excellent candidates for water desalination and/or field emissiontransitors…

Remanence of radicals after etching

How to chemically modify pore interior?

Remaining radical fraction profile per track

Decay : 1/r2

Rmoy(nm)

f averaged and normalized to a single track

Images CLSM of PVDF-g-PAA membranes modified withethylenediamine prior to radiografting.Images are xz-plan (cross-section) re-building of xy-planseries.

Red: Fluorescein isothiocyanate reacts with aminefunctions, i.e. oxydation

green: Alexa Fluor R hydrazide reacts with carboxylic acids,i.e. poly(acrylic acid).

Radiografting localization: Double labelling

Z

Applied Research: Early warning sensorsfor monitoring toxic metal ionsCAPTOT Technology

Travis Wade receiving the award of « Salon Pollutec » ex-project ECOSISTEM

CAPTOT Technology

Sensor for toxic metal ions

membrane

9 m

50 nm

35 nm

35

nm

Au

Autop bottom

10

20

30

40

50

60

70

80

-0,8 -0,6 -0,4 -0,2 0 0,2 0,4

25 ppb Co, Ni, Pb and Cu

Cu

rren

t (

A)

Potential (V vs Ag/AgCl)

Co

Ni

Pb

Cu Au

bottomtop

membrane

2.5 cm

7.5

cm

0

5

10

15

20

0.1 1 10 100

y = 6.2149 + 7.1206log(x) R2= 0.98664

pe

ak c

harg

e /

C

[Pb2+

] / g/L

Prices OSEO et POLLUTEC en 2012

Labscale demonstrator

ab

c d

Controlled radical polymerization inside nanopores

Radiation induced RAFT mechanism

(I) Initiation I

IMonomer

ki

P1

(II) Pm +S

Z

S R

(1) (2)

Z

S RSPm

(3)

Z

SPm S

+ R

(III) PnMonomer

kP

Pn+1 RMonomer

kP,1

P1

(IV) Pn

S

Z

S Pm+

(4)

Z

S PnSPm

Z

SPn S

Pm+

(V) Pn Pm+ Pn+m

<kt>

k

k k

k

SHI irradiation Radicals trapped in the crystallites of PVDF(I) Initiation I

IMonomer

ki

P1

(II) Pm +S

Z

S R

(1) (2)

Z

S RSPm

(3)

Z

SPm S

+ R

(III) PnMonomer

kP

Pn+1 RMonomer

kP,1

P1

(IV) Pn

S

Z

S Pm+

(4)

Z

S PnSPm

Z

SPn S

Pm+

(V) Pn Pm+ Pn+m

<kt>

k

k k

k

SHI irradiation Radicals trapped in the crystallites of PVDF

AFM : nanopore filling

R=25nm

PVDF-g-PAA membrane

78Kr31+, fluence 1010 ions/cm2

Prof. Olgun Güven

8wt%

14wt% 31wt%

43wt% 63wt%

RAFT = 3-benzylsulfanylthiocarbonylsulfanyl propionic acid (BPATT)

0

5

10

15

20

25

30

0.01 0.1 1 10 100

y = 11.203 + 8.0783log(x) R2= 0.98638

y = 4.3341 + 8.2961log(x) R2= 0.99045

Peak

cha

rge / µ

C

Log [Pb2+

] / ppb

00

5

10

15

20

25

30

0.01 0.1 1 10 100

y = 11.203 + 8.0783log(x) R2= 0.98638

y = 4.3341 + 8.2961log(x) R2= 0.99045

Peak

cha

rge / µ

C

Log [Pb2+

] / ppb

0

2

4

6

8

10

12

0 10 20 30 40 50

Pe

ak c

harg

e / µ

C

Degree of grafting / wt%

RAFT-mediated radical polymerization = improvementof sensors sensitivity

Enhancement of the efficiency of the sensors for water quality detection by a factor two

Murat Barsbay, Olgun Güven, Haad Bessbousse, Travis L. Wade, François Beuneu, Marie-Claude Clochard « Nanopore size tuning ofpolymeric membranes using RAFT-mediated radical polymerization J. Memb. Sci. (2013)

Hg2+ detection

Mercury drop electrode

+ relatively expensive

+ somewhat portables

+ wide range of detectable ions

- Mercury

- Difficult to use

+ very sensitive

Ion Selective Electrodes

+ cheap

+ Portable

+ real-time analysis

- Interferences

- Limited to some ions

+ easy to use

- Lack of sensitivity

Limit of detection for Hg2+ 0.01 ppb

Existing portable technologies CAPTÔT performances

0

20

40

60

80

100

120

140

160

-1 -0,5 0 0,5 1 1,5

I / µ

A

Potential vs Ag wire / V

Hg --> Hg2+

Au

oxygen

a)

15

20

25

30

35

40

45

50

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Potentiel vs Ag wire / V

0.100 g/l

0.050 g/l

0.010 g/l

I / µ

A

0

5

10

15

20

25

0 0,02 0,04 0,06 0,08 0,1 0,12

I /

A

concentration / g/l

b)

Source: CEA BEM may 2012

International market

Equipment sales distribution

*1 time/month analyses for a theoretical level of pollution between 10 and 50 ton/year** Daily analyses for a theoretical level of pollution >3000 tons/year

• Identified industrials

Licencing ? (5 patents)10 prototypes / year+ strip-electrodes

IDEX

Valorization: toward a technological transfert

• Potential targets: Water actors: BRGM, KWR(NL), Cogent(UK), Suez Environnement, Veolia

(SARP)…Analyses companies: SGS, (CETIM)HYTEC, Methrom(US),Trace Detect (US), Sens Aqua (No), Liquum (Fin),Applitek (Be), Elta (Fr), Trace2O (UK), Palmsens (NL),Mesureo(Fr), thermofisher(Fr), Modern Water (UK), Private medical analyses laboratories …

2016-2018

From a demonstrator to a prototype

with integrated potenstiostat

Demonstrator 1st generation (2008)

Demonstrator 2nd generation

Artview of the final prototype

Prototype 1st generation(2017) a reality!

Perspective: Uranium detection using CAPTOT

CAPTOT is based on polymer radiograftingtechnique and ASV.

ASV is an established technique for the determination of Uranium trace levels (< 1ppb) in water.[1] .

CAPTOT is planned to be used as a tool to dynamically test performances towards UO2

2+ uptake and release of the radiografted functionnalisations(prof. Al-Sheikhly team).

From:[1] M.B. Gholivand et al. “Cathodic adsorptive stripping voltammetric determination of uranium(VI) complexed with 2, 6-pyridine dicarboxylic acid” Talanta 65 (2005) 62–66.

UO2 ← UO22+ + 2e-

Perspectives in nanofluidics

… a world to explore!

Ionic conductivity experiment Results

Size selection

Coming back to fundamentals…

THANK YOU FOR YOUR ATTENTION!

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