Liquid surface studied by particle spectroscopy

Liquid surface studied by particle spectroscopy

Preparation of liquid surface

MIES = Metastables Induced Electron Spectroscopy

NICISS = Neutral Impact Collision Ion Scattering Spectroscopy

NICISS (=Neutral Impact Collision Ion Scattering Spectroscopy)

Principle:

concentration depth profile

Formamide Surface

Valence orbitals

He+, 4.5keVNICISS He+, 4.5keV-Eloss

Formamide Surface

Valence orbitals

He+, 4.5keVNICISS He+, 4.5keV-Eloss -E

TBPBr /FA (tetrabutylphosphonium bromide in formamide)


CNO

PBr

0

5000

10000

15000

2 3 4 5 6 7 8

TOF [µs]

inte

nsity

[co

unts

/h/n

A]

solvent

0.01 molal

0.03 molal0.05 molal

0.20 molal0.41 molal

1.50 molal

Solution of Tetrabutylphosphonium Bromide in Formamide

0

1000

2000

3000

4000

5000

6000

4.0 4.5 5.0 5.5 6.0 6.5 7.0TOF [µs]

inte

nsi

ty [

cou

nts

/nA

/h]

spectrum of formamide

back groundsputtered hydrogen

fit to the back ground

oxygen step

-5

0

5

10

15

20

25

30

-30 -20 -10 0 10 20 30 40

depth [Å]

conc

ent

ratio

n [1

0-3

mo

l/cm

3 ]

measurement

Gibbs dividing plane



0

500

1000

1500

2000

2500

3000

3 3.5 4 4.5 5 5.5TOF [µs]

inte

nsi

ty [

cou

nts

/h/n

A]

solution

pure solvent

back ground of the solution ( x )

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

-30 -20 -10 0 10 20 30 40 50 60 70depth [Å]

con

cen

trat

ion

[10

-3m

ol/c

m3] Reihe1

Reihe2

Bu4P+

Br-

POPC in HPN

POPC (=1-Palmitoyl-2-Oleoyl-SN-Glycero-3-Phosphocholine)

HPN (=3-hydroxipropionitrile)

POPC in HPN

30

34

38

42

46

1.E-05 1.E-04 1.E-03 1.E-02

cPOPC [mol·kg-1]

[

mN

·m-1

]

0.0E+00

5.0E-11

1.0E-10

1.5E-10

2.0E-10

2.5E-10

1.0E-06 1.0E-05 1.0E-04 1.0E-03

cPOPC [mol·kg-1]

Ge

PO

PC [

mo

l/cm

2]

from surface tension

from NICISSsolute

excsolute dd G

solute

solute

soluteexcsolute

fdcd

adTR

d

lnln

ln

G

POPC in HPN

Activity coefficient of POPC below CMC

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

0.00E+00 2.00E-05 4.00E-05 6.00E-05 8.00E-05 1.00E-04 1.20E-04 1.40E-04 1.60E-04

cPOPC [mol/kg]

solutesoluteexcsolute

fdcdTR

dlnln

G

POPC in HPN

Evaluation of the chemical potential of POPC for all concentrations

POPC / HPNchem. Potential normalized to zero at lowest POPC-concentration

y = 2239.2Ln(x) + 26210

R2 = 0.9747

0.E+00

1.E+03

2.E+03

3.E+03

4.E+03

5.E+03

6.E+03

7.E+03

8.E+03

9.E+03

1.E+04

0.E+00 2.E-04 4.E-04 6.E-04 8.E-04 1.E-03 1.E-03 1.E-03 2.E-03 2.E-03 2.E-03

nominal concentration [mol/kg]

chem

pot

entia

l [Jo

ule/

mol

]

excsolute

solute

dd

G

POPC in HPN. Evaluation of the chemical potential of POPC.

Logarithmic plot demonstrates ideal behavior in pre-micellar range

POPC / HPNchem. Potential normalized to zero at lowest POPC-concentration

y = 2239.2Ln(x) + 26210

R2 = 0.9747

0.E+00

1.E+03

2.E+03

3.E+03

4.E+03

5.E+03

6.E+03

7.E+03

8.E+03

9.E+03

1.E+04

1.E-06 1.E-05 1.E-04 1.E-03 1.E-02

nominal concentration [mol/kg]

che

m p

ote

ntia

l [Jo

ule

/mo

l]

Pt clusters, embedded in IL

M rho [g/cm^3] n [mol]

Pt 195.1 19.77 6.15E-05

Polyvinylpyrrolidon 111.42 1.2 6.15E-04

BDiMIm 302.32 1.4 6.60E-04

CD3OD 36 0.847 1.65E-02

Sample from DC Knapp, Dr. Müller, Prof. Lercher, TU München

Polyvinylpyrrolidon Monomer Trimer

NO

H

HH

HH HH

H

H

NO

H

HH

HH HH

H

H

NO

H

HH

HH HH

H

HH H

NO

H

H

H

HH

HH HH



Pt 195.1 19.77 6.15E-05


BDiMIm 302.32 1.4 6.60E-04

CD3OD 36 0.847 1.65E-02

Sample from DC Knapp, Dr. Müller, Prof. Lercher, TU München

BDiMIm= Butyl Dimethyl Imidazolium Triflat

F

F

F

S-

O

OO

NN

C+

HH

H

H

HH

H H

HH

H H

H


13.9 m

solution from Dr. Müller


Pt 195.1 19.77 6.15E-05


BDiMIm 302.32 1.4 6.60E-04

CD3OD 36 0.847 1.65E-02

1.8 m

Preparation of thick layer:

spreading of 30 L on 4.8cm2

Preparation of thin layer:

dissolving in 8-fold amount of methanol &

spreading of 30L on 4.8cm2

Pt clusters, embedded in IL NICISS

Pt

Pt

S

S

F

F

O

O

N

N

C

C

-500

0

500

1000

1500

2000

2500

3000

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

I korr1 (t)

selection for f it

H-recoil

steps

recoil & steps

13.9 m, 84°


1.8 m, 84°

Pt

Pt

S

S

F

F

O

O

N

N

C

C

-500

0

500

1000

1500

2000

2500

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

I korr1 (t)

selection for f it

H-recoil

steps

recoil & steps

Pt

-50

0

50

100

150

200

250

300

2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5

TOF [s]

cou

nts

Pt 78°

Pt 68°

Pt 58°

Pt 48°

Pt 38°

Pt 28°

Pt 18°


1.8 m

Pt

Pt

S

S

F

F

O

O

N

N

C

C

-500

0

500

1000

1500

2000

2500

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

I korr1 (t)

selection for f it

H-recoil

steps

recoil & steps

Pt

-100

0

100

200

300

400

500

600

2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5

TOF [s]

cou

nts

Pt 78°

Pt 68°

Pt 58°

Pt 48°

Pt 38°

Pt 28°

Pt 18°


Pt

Pt

S

S

F

F

O

O

N

N

C

C

-500

0

500

1000

1500

2000

2500

3000

2 2.5 3 3.5 4 4.5 5 5.5 6 6.5

I korr1 (t)

selection for f it

H-recoil

steps

recoil & steps

13.9 m

model consideration NICISS

surface

depth

surface

depth


surface

depth


surface

depth


surface

depth


surface

depth


surface

depth


surface

depth


surface

depth


surface

depth


Pt

-100

0

100

200

300

400

500

600

2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5

TOF [s]

cou

nts

Pt 78°

Pt 68°

Pt 58°

Pt 48°

Pt 38°

Pt 28°

Pt 18°


13.9 m

Pt

-50

0

50

100

150

200

250

300

2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5

TOF [s]

cou

nts

Pt 78°

Pt 68°

Pt 58°

Pt 48°

Pt 38°

Pt 28°

Pt 18°

1.8 m

sample of Pt clusters, embedded in IL, goniographic NICISS

13.9 m 1.8 m

58°

-100

0

100

200

300

400

500

600

0 50 100 150 200

Fit

from exp.

78°

0

50

100

150

200

250

300

0 50 100 150 200 250 300

Reihe1

Reihe2

5%

70%

Pt concentration in bulkPt clusters

Pt atoms? percentage of this fraction is evaluated from 3D model

thin layer (~0.8nm) IL

Documents

Liquid surface studied by particle spectroscopy