KyaKyaRRosa -osa -11908908

4

Kya Rosa - 1908Kya Rosa - 1908

Inaugural Lecture and Address Inaugural Lecture and Address

at University of Pretoria, at University of Pretoria, 28 July 200528 July 2005

Virtual Thermodynamic Potential

Ignacy Cukrowski

Professor and Head

Department of Chemistry

[email protected]

Inaugural Lecture at UP Inaugural Lecture at UP 28 July 200528 July 2005

Outline of the presentation

Introduction

A bit of historyDynamic physical chemistry (kinetics) Equilibrium physical chemistry (thermodynamic)

Potentiometric (equilibrium) data by non-equilibrium equationSolution chemistry - work done in South Africa

Dynamic (non-equilibrium) data by potentiometric equation

Virtual thermodynamics in action - examples

Conclusions

Department of Chemistry at UP – my vision

Acknowledgements

4


Alessandro Giuseppe Antonio Anastasio(1745 – 1827)VOLTA

On 20 March 1800, Volta, Italian physicist, informs the President of the Royal Society, Sir Joseph Banks, of the invention of the pile.

Pile device was the first in history "electric battery”,a source of continuous current

New source of energy


Volta demonstrating the Voltaic Pile to Napoleon

Bonaparte

In June 1800, Napoleon reconfirms Volta as Professor of Experimental

Physics

at the University of Pavia.

Till today presidents of some European countries confirm scientists as Full Professor at Universities


Michael Faraday (1791-1867 )English physicist and chemist

Faraday at work in his bottle-lined laboratory in the basement of the Royal Institution in London.


Michael Faraday

Theory of electrochemistry

Faraday's two laws of electrochemistry:

(1) The amount of a substance deposited on each electrode of an electrolytic cell is directly proportional to the quantity of electricity passed through the cell.

(2) The quantities of different elements deposited by a given amount of electricity are in the ratio of their chemical equivalent weights


Here, members of the Royal Institution attend a lecture on

Magnetism and Light

by Professor Faraday

(London 1846)

Many years later, as Maxwell later freely admitted, the basic ideas for his mathematical theory of electrical and magnetic fields came from Faraday.


Faraday introduced to science

paramagnetics and diamagnetics

Tyndall said:

"Michael Faraday was the greatest experimental philosopher the world has ever seen; ... the mighty investigator”

Every year on Christmas Day, he presented at the Royal Institution his Faraday Lectures for Children

Christmas lectures for children continue to this day.

Two electrical units (for capacitance and charge) were named after Michael Faraday to honour his accomplishments


The discoveries by Galvani, Volta, Faraday and others indicated a promising future for dynamic electrochemistry.

Walther Hermann Nernst (1864 - 1941)German physicist and chemist

The Nobel Prize in Chemistry 1920Nobel Lecture, December 12, 1921Studies in Chemical Thermodynamics


The Nernst Equation and the Third Law of Thermodynamics

RTnFEK o=lnQ

nFRTEE ln−= o ∆rG° = –RT ln K

∆rG° = –nFE°

The brilliant thermodynamic analysis made by Nernst (1891) opened up excellent ways of getting at the

free energy changes in chemical reactions

NERNST Father of Equilibrium ElectrochemistryOverthermodynamical approach prevents

development of charge transfer at interfaces.

The direct conversion of chemical to electrical energy

was stopped for some 50 years.


Dynamic Electrochemistry becomes recognisedMax Volmer (1885 – 1965)

German professor of physical chemistry and electrochemistry

Max Volmer’s work formed the basis of phenomenological kinetic electrochemistry

Butler-Volmer equation

QnFRTEE ln−= o

Max Volmer became a director of the Institute of Physical Chemistry

and Electrochemistry.


Dynamic Electrochemistry – highest Honours

Jaroslav Heyrovský, father of electroanalyticalchemistry, recipient of the Nobel Prize.

All voltammetric methods used now in electroanalytical chemistry originate from polarography developed by him.

Jaroslav Heyrovský and his son Michael

(1890 - 1967)Charles University, Prague

1959


Dynamic Electrochemistry - well established science

Wiktor Kemula The portrait of Frumkinpainted in the Picasso's manner

Alexander Naumovich Frumkin"father" of Russian electrochemistry.

A.N. Frumkin and J. O'M. Bockris (U.S.A. 1960)

According to Bockris:

“The Great Nernstian Hiatus”

was ended by Frumkin

Inaugural Lecture at UP Inaugural Lecture at UP 28 July 2005

EQUILIBRIUM E-CHEMISTRY

DYNAMIC E-CHEMISTRY (KINETICS)

28 July 2005

M. Volmer J. Heyrovský A.N. FrumkinWalther Hermann Nernst

Physical Chemistry textbook

by Atkins

Physical Chemistry textbook

by AtkinsPhysical Chemistry textbook

by Levine

Analytical Chemistry

textbooks

Analytical Chemistry

textbooks


Metal-Ligand interactions ( MpLqHr)Model of a Metal-Ligand system & thermodynamic stability constants


DYNAMIC E-CHEMISTRY

Glass electrode potentiometry

Nernst equation

Thermodynamic potential

Voltammetric techniques

Many simplified equation

Thermodynamics

Kinetics (electron transfer)

Transport (to & from interface)

Two different WORLDS that did not talk to each other at all.


0

1

2

3

4

5

6

7

8

9

10

-0.65 -0.60 -0.55 -0.50 -0.45 -0.40 -0.35 -0.30 -0.25 -0.20Potential / V

Nor

mal

ised

cur

rent

(A)

p[H](1)p[H](n)

p[H]

Dynamic and labile M-L system

0

1

2

3

4

5

6

7

8

9

10

-0.70 -0.60 -0.50 -0.40 -0.30 -0.20Potential / V

Nor

mal

ised

cur

rent

∆ Ip

(B)

p[H](1)

p[H](n)

Inert metal complexes

0

1

2

3

4

5

6

7

8

9

10

-0.70 -0.60 -0.50 -0.40 -0.30 -0.20Potential / V

Nor

mal

ised

cur

rent

(C)

p[H](1)

p[H](n)

p[H]

Mixed (labile & inert) M-L system

Homogeneous

Equilibria

Reversible

Interfacial

kinetics?Quasi-Reversible

Irreversible


jTML L

nFRT

II

nFRTE js

c ][lnln)()(

/ β=−21∆

jTMLs

c LnFRT

II

nFRTE

N

j ][lnln)()(

/ ∑=−0

21 β∆

∑=N j

TMX XXF j0

0 ][][ β

∑=N i

Tj

TYMX YXYXF ij0

00 ][][],[ β

1) Main experimental variable – ∆E

Lingane

DeFord-Hume

Leden–DeFord–Hume

Leden–Schaap–Mc Master

1941

1951

1961

1951

Still regarded as the method in the field

Harris, Quantitative Chemical Analysis, 5th ed. 1999Skoog, …Fundamentals of Anal. Chem 6th ed. 1992

Dynamic and labile M-L system

Mass-balance equations not involved

No rigorous refinement of stability constants

Limited applications with quite uncertain results


][][

LKLKDDD

ML

MLMLM++=

1

( )( )2)( )(

)()(

MN

MNNNMMNNNLML

I

IcIcIIKK

−−×=

2) Experimental variable – ∆I

Kačena and Matoušek

Inert comlex ML (at fixed pH)

Schwarzenbach

1952

1953

For over 40 years there was not a significant

progress made in the field

Is there any room for

further development?


A paradigm shift

(1996)

( ))()(

)( ][][lnln

)(

)()()(

ix

T

ixix M

MnFRT

II

nFRTEE

s

ccs

=

−−

Any kind of comlex MxL(1)yL(2)z (at any experimental conditions)

Corrected shift in potential (∆Ep or ∆E1/2) or change in potential (ISE)

Cukrowski

[M] from mass-balance equations; modelling–refinement: ECFC & CCFC

I. Cukrowski, Anal. Chim. Acta 336 (1996) 23-36

I. Cukrowski, M. Adsetts, J. Electroanal. Chem. 429 (1997) 129-137


0

50

100

150

200

250

2 3 4 5 6 7 8 9 10 11 12

p[H]

Cor

rect

ed s

hift

/ mV

Cdx(OH)y

Pbx(OH)y

Cd-DPA-2

Pb-DPA-2

Cd-PICOL

Pb-PICOLCd-HEEN

( ))(

)()( )()()()( ln

ixixix s

ccsII

nFRTEECS

−−=

Corrected shift & Experimental Complex Formation Curves

Objective function to be reproduced by theoretical model

I. Cukrowski, M. Adsetts, J. Electroanal. Chem. 429 (1997) 129-137


M + 4H + L ↔ M(H4L) βM(H4L) = [MH4L] / [M][H]4[L] M + 2H + L ↔ M(H2L) βM(H2L) = [MH2L] / [M][H]2[L] 2M + L ↔ M2L βM2L = [M2L] / [M]2[L] M + L ↔ ML βML = [ML] / [M][L] M + 2L ↔ ML2 βML2 = [ML2] / [M][L]2 M + L + OH ↔ ML(OH) βML(OH) = [ML(OH)] / [M][L][OH]

M + OH ↔ M(OH) βM(OH) = [M(OH)] / [M][OH] M + 2OH ↔ M(OH)2 βM(OH)2 = [M(OH)2] / [M][OH]2 M + 3OH ↔ M(OH)3 βM(OH)3 = [M(OH)3] / [M][OH]3 M + 4OH ↔ M(OH)4 βM(OH)4 = [M(OH)4] / [M][OH]4 2M + OH ↔ M2(OH) βM2(OH) = [M2(OH)] / [M]2[OH] 4M + 4OH ↔ M4(OH)4 βM4(OH)4 = [M4(OH)4] / [M]4[OH]4

H + L ↔ HL K1H = [HL] / [H][L]

H + HL ↔ H2L K2H = [H2L] / [H][HL]

H + H2L ↔ H3L K3H = [H3L] / [H][H2L]

H + H3L ↔ H4L K4H = [H4L] / [H][H3L]

H + H4L ↔ H5L K5H = [H5L] / [H][H4L]

H + H5L ↔ H6L K6H = [H6L] / [H][H5L]

Complexes:Protonated

Polynuclear

Labile

Inert

hydroxo

I. Cukrowski et al, Anal. Chim. Acta 379 (1999) 217-226


[MT] = [M] + βM(H4L)[M][H]4[L] + βM(H2L)[M][H]2[L]+ 2βM2L[M]2[L] + βML[M][L] + βML2[M][L]2 +

βML(OH)[M][L][OH] + βM(OH)[M][OH] + βM(OH)2[M][OH]2 + βM(OH)3[M][OH]3 + βM(OH)4[M][OH]4 +

2βM2(OH)[M]2[OH] + + 4βM4(OH)4[M]4[OH]4

[LT] = [L] + K1H[H][L] + K1

HK2H[H]2[L] + K1

HK2HK3

H[H]3[L] + K1HK2

HK3HK4

H[H]4[L] + K1HK2

HK3HK4

HK5H[H]5[L]

+ K1HK2

HK3HK4

HK5HK6

H[H]6[L] + βM(H4L)[M][H]4[L] + βM(H2L)[M][H]2[L] + βM2L[M]2[L] + βML[M][L] +

2βML2[M][L]2 + βML(OH)[M][L][OH]

)(][][ln

ix

T

MM

nFRT

Computed Complex

Formation Curve

Theoretical model

{q(RT/nF)}/p

New definition of Nernstian slope

(modelling of M-L systems)

I. Cukrowski et al, Anal. Chim. Acta 379 (1999) 217-226


Nernstian data by DYNAMIC ELECTROCHEMISTRY equation

ECFC and CCFC for Cd(II)-Glycine system studied by DPP and ISE

0

20

40

60

80

100

120

140

160

5 6 7 8 9 10 11

p[H]

Shift

in p

oten

tial /

mV

ISE: [L T]:[M T] = 5.7[M T] = 1E-3 M

ISE; [L T]:[M T] = 50[M T] = 5E-4 M

DPP: [L T]:[M T] = 400[M T] = 8.32E-5 M

( ))()(

)( ][][ln

)()(ln)()(

ix

T

ixix M

MnFRT

sIcI

nFRTcEsE

=

−−

I. Cukrowski, G. Ngigi, Electroanalysis 13 No. 15 (2001) 1242-1252


Metal-Ligand interactions ( MpLqHr)

Model of a Metal-Ligand system & thermodynamic stability constants

EQUILIBRIUM E-CHEMISTRY DYNAMIC E-CHEMISTRY

( ))()(

)( ][][ln

)()(ln)()(

ix

T

ixix M

MnFRT

sIcI

nFRTcEsE

=

−−

Potentiometric data changed to

Virtual dynamic dataThe same equation is valid for fully dynamic

and reversible M-L system studied by voltammetry

Nernst domain by equation for the dynamic data treatment at any experimental conditions

I. Cukrowski, G. Ngigi, Electroanalysis 13 No. 15 (2001) 1242-1252

I. Cukrowski, N. Maseko, Electroanalysis 15 No. 17 (2003) 1377-1388


Quantitative voltammetric analysis of a metal ion

Concentration

Cur

rent

E p = const

8


ISE response vs. [M2+]

-Log [M]

ISE

Pote

ntia

l or E

p / m

V

slope = 30 mV

2 3 4 5

ISE

pote

ntia

l / m

V

0

2

4

6

8

10

12

14

16

18

20

-0.7 -0.65 -0.6 -0.55 -0.5 -0.45 -0.4 -0.35

Applied potential / mV

Cur

rent

/ ar

bitr

ary

units

E p

‘Virtual ISE’ from polarographic results

Virtual thermodynamic dataD

PP p

eak

pote

ntia

l / m

V


0

1

2

3

4

5

6

7

8

9

10

-0.65 -0.60 -0.55 -0.50 -0.45 -0.40 -0.35 -0.30 -0.25 -0.20Potential / V

Norm

alis

ed c

urre

nt

p[H](1)p[H](n)

p[H]

Peak of a free metal ionPeak representing

all metal species Shift in Ep

{Ep(s) – Ep(c)}

H2N OH

ODPP of a labile (or dynamic) M-L system

Glycine

Cd-Glycine-OH system


0

10

20

30

40

50

60

70

80

90

100

6 6.5 7 7.5 8 8.5 9 9.5 10pH

Cor

rect

ed s

hift

in p

eak

pote

ntia

l / (m

V)ECFC CCFC

[M] from solving mass-balance

equation

( ))()(

)( ][][ln

)()(ln)()(

ix

T

ixix M

MnFRT

sIcI

nFRTcEsE

=

−−

Refinement of stability constants: complex formation curves

I. Cukrowski, Anal. Chim. Acta 319 (1996) 39 – 48.I. Cukrowski, M. Adsetts, J. Electroanal. Chem. 429 (1997) 129 - 137


Inaugural Lecture at UP Inaugural Lecture at UP 28 July 200528 July 2005Virtual thermodynamic data

)(*

)()( )(

)()(ln)( ixp

ixixp E

sIcI

nFRTcE =

+ )()()(* sIcIifcEE pp <<

y = 29.423x - 427.76R2 = 0.9998

-640

-620

-600

-580

-560

-540

-520

-7-6.5-6-5.5-5-4.5-4-3.5

Log [M ]

Cor

rect

ed E

p(ob

s) /

mV

E p* /

mV

Each datum point {Ep* at pH(i)} is theoretically calculated using

Nernst thermodynamics by dedicated software, e.g. ESTA

E = E° + 0.030 log [M]E = E° + RT/nF ln [M]

DPP as a ‘virtual’ potentiometric sensor.


I. Cukrowski, J. Zhang, Electroanalysis 16, No. 8 (2004) 612 - 626


0

2

4

6

8

10

12

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7pH

Labi

le p

eak

curr

ent

0

1

2

3

4

5

6

7

8

9

10

-0.70 -0.60 -0.50 -0.40 -0.30 -0.20Potential / V

Norm

alis

ed c

urre

nt

p[H](1)

p[H](n)

p[H]

OHHO

OO

OH

N

Cd-HIDA-OH system

I. Cukrowski, N. Maseko, Electroanalysis 15 No. 17 (2003) 1377-1388


0

20

40

60

80

100

120

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

pH

Shift

in th

e pe

ak p

oten

tial /

mV

Experimental and Computed Complex Formation Curves

( ))()(

)( ][][ln

)()(ln)()(

ix

T

ixix M

MnFRT

sIcI

nFRTcEsE

=

−−

ECFC

CCFC

Shift

Labile peak

Cd-HIDA-OH systemI. Cukrowski, N. Maseko, Electroanalysis 15 No. 17 (2003) 1377-1388


y = 29.48x - 453.80R2 = 1.00

-680

-660

-640

-620

-600

-580

-560

-7.5-7-6.5-6-5.5-5-4.5-4-3.5

Log [M ]

Cor

rect

ed p

eak

pote

ntia

l / m

V )(*

)()( )(

)()(ln)( ixp

ixixp E

sIcI

nFRTcE =

+

Virtual thermodynamic data

E = E° + RT/nF ln [M]

‘Virtual’ potentiometric [Cd] (ISE) sensor from voltammetry

Cd-HIDA-OH systemI. Cukrowski, J.M. Zhang, unpublished results


0

50

100

150

200

250

300

0 1 2 3 4 5 6

p[H]

Cor

rect

ed S

hift

in E

1/2 /

mV

Complex Formation Curves

N C

O

OH )(*

)()( )(

)()(ln)( ixp

ixixp E

sIcI

nFRTcE =

+

y = 19.62x + 174.72R2 = 1.00

-150-130-110-90-70-50-30-101030507090

-17-16-15-14-13-12-11-10-9-8-7-6-5-4log [M]

E1/

2(virt

) / m

V

(B)Virtual thermodynamic data

‘Virtual’ potentiometric Bi(III) sensor from voltammetry


Bi(III)-(Picolinic Acid)-OH system

I. Cukrowski, J.M. Zhang, A. v Aswegen, Helv. Chim. Acta, Vol. 87 (2004) 2135 – 2158


Ni-MDP-OH system

Fitting of a DCTAST wave for Ni-MDP-OH at pH 2.847

0

1

2

3

4

5

6

7

8

-1.2 -1.15 -1.1 -1.05 -1 -0.95 -0.9 -0.85 -0.8 -0.75 -0.7

Potential / V

Cur

rent


0

1

2

3

4

5

6

7

8

-1.2 -1.15 -1.1 -1.05 -1 -0.95 -0.9 -0.85 -0.8 -0.75 -0.7

Potential / V

Cur

rent


0

1

2

3

4

5

6

7

8

-1.2 -1.15 -1.1 -1.05 -1 -0.95 -0.9 -0.85 -0.8 -0.75 -0.7

Potential / V

Cur

rent


0

1

2

3

4

5

6

7

8

-1.2 -1.15 -1.1 -1.05 -1 -0.95 -0.9 -0.85 -0.8 -0.75 -0.7

Potential / V

Cur

rent


0

1

2

3

4

5

6

7

8

-1.2 -1.15 -1.1 -1.05 -1 -0.95 -0.9 -0.85 -0.8 -0.75 -0.7

Potential / V

Cur

rent

P

OH

O

CH2 OHP

OH

O

HO

MDP

Involved heterogeneous kinetics:

(irreversible electron transfer)

Irreversible and mixed M-L-OH system

I. Cukrowski, D.M. Mogano and J.R. Zeevaart, sent to J. Inorg. Biochem.


Ni-MDP-OH system

0

0.5

1

1.5

2

2.5

3

3.5

4

2.5 3.5 4.5 5.5 6.5 7.5 8.5

pH

Cur

rent

/ ar

bitr

ary

units

0

0.2

0.4

0.6

0.8

1

1.2

Nor

mal

ised

cur

rent

/ ar

bitr

ary

units

Expected

Normalised observed

Involved homogeneous kinetics:

(mixed M-L system)




Kinetics of the M-L-OH system


Virtual potential in modelling of the M-L-OH system

Ni-MDP-OH system

-1120

-1100

-1080

-1060

-1040

-1020

-1000

-11 -10 -9 -8 -7 -6

log [L]

E 1/2

/ m

V

Virtual potentialSlope = 30 mV / log [L]

M + L = ML

Virtual potentialSlope = 41 mV / log [L]

M + L = MLand M + 2L = ML2

Observed potentialSlope = 25 mV / log [L]

M + L = ML

(B)

Involved homogeneous kinetics:

(mixed M-L system)





Virtual potential (E1/2*) vs. [Ni]. DCP as a ‘virtual’ potentiometric sensor.

Ni-MDP-OH system

y = 29.613x - 864.51

-1120

-1100

-1080

-1060

-1040

-1020

-1000

-8.5 -8 -7.5 -7 -6.5 -6 -5.5 -5

log [M]

Virt

ual p

oten

tial /

mV

)(*

)()( )(

)()(ln)( ixp

ixixp E

sIcI

nFRTcE =

+




Kinetic and equilibrium data working together in refinement operations

0

0.5

1

1.5

2

6 7 8 9 10 11

pA

Zbar

M

LT:MT = 2

Formation of ML

Formation of ML2

Formation of MLx(OH)y

log β Technique ML ML2 ML(OH)2 ML2(OH)2 OF/HF Ref. DCP 8.18(01) 13.86(03) ― ― 0.45 TW GEP 7.27* 7 7.98(01) 13.85(01) ― 21.59(03) 0.060 TW 7.98(01) 13.83(01) 16.78(03) ― 0.058 TW 7.98(fixed) 13.85(fixed) 16.71(07) 20.52(45) 0.059 TW VP-DC&GEP? 7.94(02) 13.75(02) 16.75(05) ― 0.018 TW ‡

Ni-MDP-OH system



y = 0.983x + 3.5421

4

5

6

7

8

9

10

11

12

13

14

1 3 5 7 9 11 13log K MOH

log

KM

L

Ca Mg

Cd

Ni

Zn Pb

Sm Ho

SnSm-MDP = 9.55Ho-MDP = 9.74

(B)

y = 1.0591x + 3.2796

4

5

6

7

8

9

10

11

1 2 3 4 5 6 7

Sm-MDP = 9.74Ho-MDP = 9.95

CaMg

Cd

Ni

ZnPb

Sm Ho

Linear Free Energy Relationships in prediction of Log K1



0

0.5

1

1.5

2

2.5

3

0.5 1 1.5 2 2.5 3 3.5Computed pH

Cur

rent

/ ar

bitra

ry u

nits

Observed current

Expected current

Normalized current

(A)

A study of Bi(III) by 2 voltammetric techniques

Bi(III)-EDDA-OH systemM(HL) – labile; ML & ML2 - inert

I. Cukrowski, J.M. Zhang, Chem. Anal., Vol. 50 (2005) 3-36


-10

0

10

20

30

40

50

60

70

80

90

0.5 1.0 1.5 2.0 2.5 3.0 3.5

Calculated pH

Hal

f-wav

e Po

tnet

ial /

mV

pKa4 = 1.4 pKa3 = 2.36

E j

Correction for the decrease in Id

E 1/2(virt) = E 1/2(obs) corrected for E j and decrease in Id

(46 mV / log unit)

Experimental pointsE 1/2 corrected for the formation of Bi(OH)

y = –5.49x4 + 33.12x3 – 83.97x2 + 121.18x – 6.8

E 1/2(M) = 77.3 mV

∆E 1/2

∆E 1/2

(A)

A study of Bi(III) by 2 voltammetric techniques



ML(Circles)

y = 19.238x + 162.88R2 = 0.9997

M(HL) + ML(Squares)

y = 19.487x + 164.62R2 = 0.9997

ML(DPP, triangles)

y = 19.607x + 188.06R2 = 0.9994

-20

0

20

40

60

80

100

-9.2-8.7-8.2-7.7-7.2-6.7-6.2-5.7-5.2-4.7

Log [Bi]

E(vi

rt) /

mV

(B)

2 voltammetric techniques as virtual ISE in the study of Bi



y = 19.51x + 166.79

40

45

50

55

60

65

70

75

-18 -17.5 -17 -16.5 -16 -15.5log [L]

E(vi

rt) /

mV

-6.7-6.5-6.3-6.1-5.9-5.7-5.5-5.3-5.1-4.9-4.7log [M]

Slope 19 mV(ML)

Slope 26 mV (ML + ML2)

(B)Double function of virtual potential (modelling & refinement)


ML2 inertML labileM(HL) labile

0.03931.70 ± 0.0417.07 ± 0.0818.85 ± 0.07VP-DP & VP-DC

pH 1.7 and A-B

Acid-base and ligand titration voltammetric data from 2 virtual sensors refined

simultaneously by ESTA



Metal-Ligand interactions ( MpLqHr)

Model of a Metal-Ligand system & thermodynamic stability constants

( ))()(

)( ][][ln

)()(ln)()(

ix

T

ixix M

MnFRT

sIcI

nFRTcEsE

=

−−

DYNAMIC E-CHEMISTRY

Change in thermodynamic potential (ISE)

Virtual dynamic data

)(*

)()( )(

)()(ln)( ixp

ixixp E

sIcI

nFRTcE =

+

Dynamic data in the form of a virtual thermodynamic potential

QnFRTEE ln−= o


Now two different WORLDS are talking to each other

Virtual THERMODYNAMICS is working


1. Polarography-based virtual potentiometric sensor:

a) does not have linearity range limits (the response is of the widest-known linearity, by far better than reigning for so many years glass electrode)

b) is ion non-specific (opposite to real ISE)

c) in principle, several metal ions might be monitored (opposite to ISE)

d) should be possible to monitor pH (if the M-L system is known)

2. Simultaneous refinement of data from several polarographic experiments (e.g. DPP and DCP).

3. Simultaneous refinement of glass electrode potentiometric (low [LT]:[MT]) and polarographic data (large [LT]:[MT]) from several titrations.

Conclusions (Solution Chemistry)

4. Simultaneous refinement of glass electrode, and ISE or metallic potentiometric as well as polarographic data from several titrations.

5. Prediction of species formed (modelling of solution composition)must be based on the analysis of virtual potential

6. Significantly improved reliability of models and refined stability constants.


Quo Vadis?

Nobel Prize in Literature 1905

Henryk Sieńkiewicz

simplyThe Best


For any University in the world the challenge is to:

1. Accept public support and broaden its social contribution without compromising its traditional independence

2. Strike a satisfactory balance between teaching and research

3. Find an ideal blend of required and elected courses

4. Satisfy students continuous demands for better instruction and satisfy promotion criteria based mainly on faculty member’s scholarly work


Each university’s basic traditional function is to:

1. Enable students to learn from their cultural heritage

2. Help students to realize their intellectual and creative abilities

3. Encourage students to become humane and responsible people

4. Expend knowledge across the entire spectrum of disciplines

5. Add to the understanding and enjoyment of life

6. Provide imaginative solutions to the problems of society


University of Pretoria:

1. In many respects, is as any other University in the World2. Has the same social functions to perform3. Has the same aims and goals to achieve

4. Is, to some extend, a unique establishment, as any other University is

We, as the University, are not that different

But as Department of Chemistry, we are very much different

simplyThe Best


What is University known and internationally recognized for?

Number of students, or number of faculty staff?Rector, Dean, HOD (administrative leaders)?Wonderful or excellent (or unbearable) administration?Best (or worst) teaching facilities (lecture theatres or laboratories)?

No, not at all

Famous scientists (discoveries made)? Nobel prize winners – where they were educated?Nobel prize winners – where they have made their contributions?Published excellent research work

Yes, very much so

Inaugural Lecture at UP Inaugural Lecture at UP 28 July 200528 July 2005simply

The Best

TEAM WORK

Exceptional teaching

Outstandingresearch

National and internationalstanding and recognition

To become the bestimplies


The BestTo become a strong Research

Department requires

Outstanding Research

Unique Expertise in the Department

Centre of Excellence

Strong research activities

Existing Research

Build on existingstrengths

Develop potential strengths


The Best

Promote fundamental and applied research

App

lied

Res

earc

h

THRIP

Contractual work

Industrialpartners

Diff

eren

t sou

rces

of in

com

efr

om re

sear

chac

tiviti

es

Fund

amen

tal

Res

earc

h


The BestDedication to

highest quality teaching

1. Excellence in teaching of 1st year chemistry

2. Establish and support a team of staff members dedicated to education

3. Research in education to be tested on our own chemistry students(continuous refinement of operation in improving educational goals)

4. Well-designed teaching program throughout the whole chemistry course, from 1st to 4th year level

5. Promote and support students with outstanding performance in chemistry


The BestOperational Structure of the Department

CommitteeLeaderHOD

Committee

EXCO

Tim

e-ta

bled

and

ad

hoc

mee

tings

Ann

ual r

epor

t

1

3

4

2

Gen

eral

Sta

ff

Mee

ting

TEAM WORK


Operational Structure of the Department

Departmental Committees

1. Educational Research Activities (ERA) - Marietjie Potgieter2. Departmental Teaching Coordination Committee - Wentzel Schoeman3. Research Coordination Committee (RCC) - Simon Lotz4. Maintenance and Safety Committee (MSC) - Robert Vleggaar5. Communication (liaison, publicity) Committee (CC) – Wentzel Schoeman6. Aesthetics Committee (AC) – Christien Strydom7. Support and Technical Staff Committee (STSC) – Robin Muir8. Fixed Facilities Committee (FFC) – Peet van Rooyen9. Centre for Interfacial Chemistry Committee (CICC) – Ignacy Cukrowski10. IT (PhD students and Staff Facilities) Committee (ITC) – Peet van Rooyen11. Finance Committee (FC) – Robert Vleggaar

8

Inaugural Lecture at UP Inaugural Lecture at UP 28 July 200528 July 2005Recent students involved in solution chemistry

University of Pretoria

Wits University

Valentine ChristienPreeti

Anton

Tumaini

Jian CarenCarina

Castelo Branco

Winny Geoffrey

Janine

Daniel

Philemon

Industry (SASOL, Anglo-Platinum, NECSA, CISA, PBMR)Metrohm (Switzerland) and Swiss Lab (SA)

NRF

Co-workers (local and abroad)

Acknowledgments

KyaKyaRRosa -osa -11908908

Documents

Transcript of KyaKyaRRosa -osa -11908908