Post on 18-Nov-2014
description
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