MATERIAL FOR SMART ELECTROCHEMICAL APPLICATIONS

ION JELLY®: A TAILOR-MADE CONDUCTING

Pedro Vidinha, Nuno M.T. Lourenço, Tânia Carvalho, Ana R. Brás, Teresa S. Silva, Abhik Mukhopadhyay, Crístina M. Cordas, Maria J. Romão, Madalena Dionisio, Joaquim M.S.Cabral, Luis P. Fonseca , Carlos A.M. Afonso& Susana Barreiros.

A light, flexible conducting biopolymer

- Ajustable to a great variety of surfaces

Thermal stability (up to 180 ºC)

Large electrochemical window

Bio-compatible

Condutivity above 10-4 S.cm-1

Enviromentally friendly

PT PATENT 103765WO PATENT submited

ION JELLY®: A TAILOR-MADE CONDUCTING MATERIAL FOR SMART ELECTROCHEMICAL APPLICATIONS, paper submitted

Ionic Liquids - Are liquids made entirely of ions Organic cation and organic or inorganic anion

Wide range ionic conductivity, 0.1-80 mS cm-1

Large electrochemical window (4-5.7 V)

Thermal stability (over 300 ⁰C)

Negligible vapour pressure

Gelatin

Contains in it’s structure a large number of amino-acids residues

Prepared from the thermal denaturation of collagen or after an alkaline or acid pre-treatment

One of the abundant biopolymers in earth

Gly Gly

Gly

4Hyp

Synthesis

Gelatin

Ionic liquid

Viscous homogeneous solution

Mixing above 35 ºC

Transparent flexible films

Flexible blocks

Room temperature

water

N NNRR

Synthesis Cation Anion Il/gelatin ratio

(w/w)Ion jelly State

[bmim] (CN)2N-

1:1 Solid Transparent films.1:3 Solid Transparent films.6:1 Liquid gel

Aliquat® (CN)2N- 1:1 No Ion Jelly formation

[Hmim] Cl- 1:1 Solid Transparent films.

[bmim] Cl- 1:1 Solid Transparent films

[omim] Cl- 1:1 Solid Transparent films.[C10min] Cl- 1 Solid Transparent films

Aliquat® Cl- 1 No Ion Jelly formation

[bmim] PF6- 1 No Ion Jelly formation

[bmim] BF4- 1 Compact rigid solids

[bmim] NTF2- 1 No Ion Jelly formation

[bmim] EtOSO3-

1:1 Solid Transparent films1:3 Solid Transparent films

Anion Polarity essential for the ion jelly synthesis

Cation plays an important role – hydrogen bounding

Anions and Gelatin water affinity

Anion Coordination strength

Phase Separation

NTF2-PF6

-(CN)2N-EtOSO3-

Gelatin binds strongly to the water

(CN)2N-EtOSO3- NTF2

-PF6-

Gelatin strips the water from IL

BF4-

Is half-way on this two cases

Water affinity Coordination strength

Compact rigid solids

Charaterizarion

-16

-14

-12

-10

-8

-6

-4

-2

0

2

4

0 50 100 150 200 250 300

T ºCh

eat

flo

w m

W

gelatina- BminDCA R=1

gelatina

Differences between water gelatin and Ion Jelly

Ion jelly

Differential Scan Calorimetry (DSC)

Water gelatin

Ion jelly is stable up to 180 ºC

Water removal

Charaterizarion gelatin [bmim][N(CN)2] LI/gelatina = 3)

[emim][EtOSO3]

(LI/gelatina = 3)

Water-based gelatin films exhibit three main diffracting rings at approximately 12 Ǻ, 4 Ǻ and 2.8 Ǻ

High resolution ring arises from the residues periodicity of each helices turn. The rise per residue along the helical axis is 2.9 Ǻ

Low resolution ring corresponds to the diameter of the super helix aggregate of the film

Pronounced modifications in the conformation of the gelatin when the ionic liquid is present.

X-Ray diffraction

Charaterizarion

[Hmim][Cl](R=1)

[C10mim][Cl](R=1); [emim][EtSO4](R=1)

[bmim][Cl](R=1)

[bmim][N(CN)2](R=3)

[bmim][N(CN)2](R=1)

[Him][Cl](R=1);

Condutivity The conductivity of the ion jelly materials is affected by the IL used

IL-[bmim][N(CN)2] 1.1x10-2

[bmim][N(CN)2](R=1) 8.6x10-5

[bmim][N(CN)2](R=3) 1.6x10-4

IL- [bmim][Cl] 3.0x10-2

[bmim][Cl](R=1) 8.0x10-4

IL- [emim][EtSO4] 8.0x10-2

[emim][EtSO4](R=1) 2,5x10-4

S cm-1

Decrease in conductivity on ion jelly films

25 ⁰C

Several systems exhibit a very reasonable conductivity 10-5-10-4 S cm-1

Applications

Besides the ionic conductivity

the material also exhibits electronic conductivity

Cellulose surface

+- - +

[emim][EtSO4](R=1)

[emim][EtSO4](R=1)

O

NN

O

NH22 H2O2

HRP

3 H2O

NN

O

NOH

SO3H

PSA(Phenol-4-sulfonic acid)

4-AAP(4-aminoantipyrine) Quinone-imine

product

NaHSO4

A

B

Applications

Horseradish peroxidase as a model system

Biosensor

A- Free HRP; B- Immobilized HRP in Ion Jelly at liquid state; C- Immobilized HRP in Ion Jelly

film after 17 days stored at 4ºC; D- Immobilized HRP in Ion Jelly film after 34 days stored at

4ºC; F- Immobilized HRP in Ion Jelly film after 40 days stored at 4ºC.

Ion Jelly could be a suitable matrix for the immobilization of HRP

Horseradish peroxidase immobilized in [bmim][N(CN)2](R=3) Ion Jelly

40 days

17 days 34 days

Free HRP

initialGel state

POSTER 91

Applications

A B

15th cycle

1st cycle

10 mV/s10 mV/s

10 mV/s

Immobilized protein response

Electrochemical Behaviour The Ion Jelly films presented complex electrochemical behaviour Several redox processes that evolve with the continuous potential cycling

A new cathodic process become visible at approximately -0.430 V vs Ag/AgClIt indicates that the direct electron transfer between the film and the cyt c was achived. Cytochrome c

POSTER 89

Anaerobic conditions showed that these processes are related with the formation of hydroxide species in the interface between the film and the carbon electrode

Final remarks

Ion Jelly interesting concept to the develop of conducting transparent polymers

Water plays an essential role of ion jelly physical-chemical properties

besides ionic conductivity ion jelly also exibits electronic conductivity

bioapplications could also made using this material as a conducting matrix

REQUIMTE- FCT/UNL

Prof. Joaquim S. Cabral Prof. Luis FonsecaNuno LourençoCristina Cordas

IBB – IST

Prof. Carlos AfonsoPedro Vidinha

CQFM – IST

Acknowledgments

Prof. Susana Barreiros Tânia Carvalho

Prof. Madalena DionísioAna Rita Brás

Prof. Maria João RomãoTeresa SilvaAbhik Mukhopadhyay

Prof. Jorge ParolaCarlos Pinheiro

Thank you very much for the attention!

Pedro Vidinha, Nuno Lourenço and Crístina Cordas - FCT post-doc Grants

Non soluble in water