5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 2
Application of X-ray
reflectivity and X-ray
standing wave techniques to
soft matter studies
Oleg Konovalov
ESRF-The European Synchrotron, France
ID10 - Soft Interfaces and Coherent Scattering
Beamline.
OUTLOOK
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
3
1. Introduction
2. Surface sensitivity
3. Theory and Applications of
• X-ray reflectivity
• X-ray Standing waves
4. Conclusions
Page 4
A MODEL OF INTERNATIONAL COOPERATION: 21 PARTNER NATIONS
13 Member states:
France 27,5 %
Germany 24 %
Italy 13,2 %
United Kingdom 10,5 %
Russia 6 %
Benesync 5,8 %(Belgium, The Netherlands)
Nordsync 5 %(Denmark, Finland, Norway, Sweden)
Spain 4 %
Switzerland 4 %
8 Associate countries:
Israel 1,5 %
Austria 1,3 %
Centralsync 1,05%(Czech Republic, Hungary, Slovakia)
Poland 1 %
Portugal 1 %
South Africa 0,3 %21 partner nations
Members of staff: 630 of 40 different nationalitiesC
on
tribu
tion
to th
e b
ud
ge
t in %
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
A UNIQUE SITE FOR RESEARCH AND INNOVATION
Page 5
Institut
Laue-Langevin
European
Molecular Biology
LaboratoryInstitut de Biologie
Structurale
European
Synchrotron
Radiation Facility
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
AT THE HEART OF THE GLOBAL INNOVATION CAMPUS GIANT
Page 6
Assembling research, innovation
and higher education in one location
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
The X Ray-Imaging groupID10: THE SOFT INTERFACES AND COHERENT SCATTERING BEAMLINE
Page 7 5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
263944.55260.461.565.7 056.5 29.9323670m
EH2 (Coherent Scattering) EH1 (Liquid Surfaces and Interfaces Scattering)
Photo by Pierre Jayet
ID10 BEAMLINE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 8
ID10: The Soft Interfaces and Coherent Scattering Beamline
• Flux: ~1013 ph/s @200 mA
• Energy range: 7-30keV
• Focusing (v): ~6 mm
• Sample-Detector distance 4m
• Anomalous option
• Brilliance: B~1020
(photons/s/mm2/mrad2/0.1%BW) l=1 Å
• Coherent flux: Ic= 8.0x1010 coh.ph./s/(10x10mm2 )
• Sample-Detector distance 7m
ID10-SI ID10-CS
X-ray photon correlation spectroscopy (XPCS)
(time window of 10-8 s < t < 10+3 s)Study of dynamics in various condensed matter systems:
Colloidal suspensions, gels, supercooled liquids, polymers,
Atomic/molecular motion in glasses and alloys, critical
fluctuations, aging behavior, dynamics of liquid surfaces.
Coherent X-ray Diffraction imaging (CXDI)High resolution 2D and 3D imaging of non-crystalline
isolated specimens, biological samples with nano-
meters resolution
X-ray Reflectivity (XRR)organic and inorganic films structure,
complex fluids, polymers, “green” chemistry,
surfaces and interfaces
Grazing Incidence Diffraction (GID)Langmuir films, membranes, macromolecules,
organic solar cells
GI Small-Angle X-ray Scattering (GISAXS)2D organization of nano-scaled systems
GI X-ray Fluorescence (GIXF)elements distribution at interfaces
Techniques
Main Parameters
SOFT CONDENSED MATTER - INCREASING LEVEL OF COMPLEXITIES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov9
Soft matter - variety of physical states that
are easily deformed by thermal stresses
or thermal fluctuations.
o Liquids
o Colloids
o Polymers
o Surfactants
o Foams
o Gels
o Granular materials
o Biological materials
o …
Pierre-Gilles de Gennes
Nobel Prize in physics in 1991
SOFT CONDENSED MATTER - INCREASING LEVEL OF COMPLEXITIES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov10
Soft matter - variety of physical states that
are easily deformed by thermal stresses
or thermal fluctuations.
o Liquids
o Colloids
o Polymers
o Surfactants
o Foams
o Gels
o Granular materials
o Biological materials
o …
Soft condensed matter science
covers a large range of length
scales from nanometre to several
micron
WHY STUDY SURFACES, INTERFACES AND THIN FILMS
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov11
? phase boundary
? crystal growth
? chemical reaction on surfaces
catalysis
? physics of 2D systems
? thin films, membranes
? ….
HOW TO STUDY SURFACES AND INTERFACES ?
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 12
2
exp N
k
kk rqifqI
22~ fNNfNI BS
B
S
B
S
B
S
d
d
N
N
I
I
3
4
7
1010
10
100
100
m
nm
I
I
B
S
m
X-rays
Detector
dS
dB
SURFACE SENSITIVITY
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
13
aT
aan1
n2
kIkR
kT
rk IiII eAE rkR
iRR eAE
rkTiTT eAE
z
x
TRI AAA
T
T
R
R
I
I kAkAkA
Wave and its derivative are continuous at z=0
RI kkk
Tknk
For X-rays:el
er
l
2
2
in 1 610~ 1na 2~c
zkzikTkiT TTT
eeAeA aaa ImRez
TTT i aaa ImRe Intensity falls off with 1/e penetration depth L
Tk aIm2
1L
- component
ml
4
nn
nT
1
2
cos
cos
a
a
Snell's law
mradc ~a
SURFACE SCATTERING TECHNIQUES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 14
XR
X-ray Reflectivity (α=β, γ =0)
In-depth electron density profile – thickness, density and
roughness of films
GISAXS
Grazing Incidence Small-Angle X-ray Scattering (α < αc,
γ 0, β 0)
Particle geometry, size distributions and spatial
correlations on nanometer scale
GID
Grazing Incidence Diffraction (α < αc, γ 0, β 0)
Two dimensional crystals (lattice parameters, molecular
structure, tilt angle of molecules, in-plain correlation lengths
GIXF
Grazing Incidence X-ray Fluorescence
(α < αc, γ = 90°)
In-depth elemental distribution profile
α / αC
Dαi < 0.1αi
αβΛ(ρ, α)
SUBSTRATE
)1(
fdFILM
)2(
fd
bulk
surface
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
102
103
Pen
etr
ati
on
dep
th,
1/A
Grazing angle, a/ac
Water @ λ=1.55 Å
Pen
etra
tion
dept
hΛ
, Å
αi 0.1˚
at 8 keV
a
g
qx
qz
qy
a
g
ag
l
sinsin
sincos
coscoscos2
q
ID10-SI: SIMULTANEOUS MULTIPLE DETECTION SCHEME
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 15
Large area detectors(simultaneous GID/GIWAXS and GISAXS)
GISAXS
GID/GIWAXS
XRR
Fluorecence
XRS
X-RAY REFLECTIVITY (XRR)
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 16
incidence
beam
scattered
beam
s
β=αα
I0 I
qZ
X-RAY REFLECTIVITY PRINCIPLE
Page 17
0.0 0.2 0.4 0.6 0.8 1.010
-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Refl
ecti
vit
y
Qz, A
-1
2
22
222
sinsinsin
sinsinsin
4
4)(
C
C
zF qRaaa
aaa
l
l
qx
hea
d
wat
er
tail
(z)
'(z)
s
Z
4
4
16)(
z
czF
q
qqR
Asymptotic behaviour (qz>3qc)
2
0
exp)(1
)()( zziqz
zqR
I
IqR z
s
zFz
la /sin4zq elec r la 212sin2
incidence
beam
scattered
beam
s
β=αα
I0 I
qZ
Subphase
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
XRR: FRESNEL FORMULAS
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
18
a
a in
n
nT
1cos
cos
1
2
aT
aan1
n2
kIkR
kT
rk IiII eAE rkR
iRR eAE
rkTiTT eAE
z
x
TRI AAA
T
T
R
R
I
I kAkAkA
Wave and its derivative are continuous at z=0
RI kkk
Tknk
aa
aa
aa
aa
aa
aa
2sinsin
2sinsin
cossin
cossin
sinsin
sinsin
2
2
22
22
21
21
n
n
nn
nn
A
Ar
T
T
I
R
T
T
I
R
nn
nn
A
Ar
aa
aa
sinsin
sinsin
12
12
||
||
||
TI
T
nn
n
A
At
aa
a
sinsin
sin2
21
1
TI
T
nn
n
A
At
aa
a
sinsin
sin2
12
1
||
||
||
ca 2sin2
elec r la 212
XRR: REFLECTIVITY CALCULATION (PARRATT VERSION )
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
19
0: d0, 0, 0, s0
j: dj, j, j, sj-1,j
j+1: dj+1, j+1, j+1, sj,j+1
M-1: dM-1, M-1, M-1, sM-2,M-1
M: dM, M, M, sM-1,M
Rj,j+1
Rj+1,j+2Tj,j+1
Tj-1,j
j
j+1
0
1: d1, 1, 1, s1
R0,1
T0,1
Q
Parratt L.G. Physical Review., 1954, v.95, p.359
Reflectivity is I(q)=R0,1(q)2,
where R0,1(q) is calculated from
recursive formula
R aR F
R Fn n n
n n n n
n n n n
1 14 1 1
1 11,
, ,
, ,
Rn,n+1=an2En
R/En,
Fn-1,n=(n-1-n)/(n-1+n),
n=(Nn2+cos2())1/2,
an=exp(-ikndn/2),
n=0,1,2,...,M; k=2/l,
l- wave length,
En , EnR –amplitudes of transmitted and
reflected fields in the layer n,
dn – thickness of layer n, material index
Nn=1-n-in;
n=M for substrate,
RM,M+1=0.
WHAT IS WHAT IN X-RAY REFLECTIVITY
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 20
0.0 0.2 0.4 0.6 0.8 1.0
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
Re
fle
ctivity
Qz, 1/A
XRR: TYPICAL EXAMPLES OF REFLECTIVITY CURVES
Page 21
0.00 0.05 0.10
1E-4
1E-3
0.01
0.1
1
Re
fle
ctivity
Qz, 1/A
air-H2O
H2O-Si
air-Si Media 1: Qzc1
Media 2: Qzc2
Qzc
2
1
2
2 zczczc QQQ
Electron Density
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
XRR: TYPICAL EXAMPLES OF REFLECTIVITY CURVES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 22
0.00 0.02 0.04 0.06 0.08 0.10
1E-3
0.01
0.1
1
Re
fle
ctivity
Qz, 1/A
/=100
/=10
/=4
inn
n1
1
2
Media 1: n1
Media 2: n2
Ratio between imaginary and real part of the refraction index decrement
XRR: TYPICAL EXAMPLES OF REFLECTIVITY CURVES
Page 23
0.0 0.2 0.4 0.6 0.8 1.0
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
DQz=2/d
Re
fle
ctivity
Qz, 1/A
H2O film on Si
d=20 A
d=40 A
d=80 A
Film thickness
d= 2/DQz
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov24
0.0 0.2 0.4 0.6 0.8 1.0
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
Re
fle
ctivity
Qz, 1/A
air/20A/80A/Si
Film thickness: many layers
d1=2 nm
d2=8 nm
XRR: TYPICAL EXAMPLES OF REFLECTIVITY CURVES
Page 25
0.0 0.1 0.2 0.3 0.4 0.5
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
Re
fle
ctivity
Qz, 1/A
s=0 A
s=3 A
s=5 A
4~
zq
4~
zqg
s
l
sin
4zq
qz
kf
ki
Interfacial roughness
))(exp( 2
zqsg
2
21
212
2,1
g
F
)(2sin2
jjj i
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
XRR: TYPICAL EXAMPLES OF REFLECTIVITY CURVES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 26
0.0 0.2 0.4 0.6 0.8 1.0
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
Re
fle
ctivity
Qz, 1/A
Multilayer (d=32A)
10xD/Si
0.5xD+10xD/Si
10xD+0.5xD/Si
Periodic structure: 1D crystal
Nd
d
½ d
½ d
VAPOUR-LIQUID INTERFACE STRUCTURE ?
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov27
How liquid is terminated ?
What interface brings to the
molecules arraignment ?
XRR: REFLECTIVITY ON AIR-WATER INTERFACE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov28
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.710
-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Reflectivity
Qz, A-1
measurement
theory: s=0 A
theory: s=3.9 A D
gg
s/2 2
||
||||2
gq
dqqTkB
max
0
2
||
2 /ln4
qB gqTk
gg
s D
ggs
/ln
2
max2
g
qTkB
D
110
max
33 102.1,/10
,/72,20
D
mqmkg
mmNCT o
g
m10104 s
Buff, Lovett, Stillinger, Phys.Rev.Lett., 15, 621 (1965)Braslau at al., Phys.Rev.Lett., 54, 114 (1985)
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 29
Examples
REFLECTIVITY ON AIR-MERCURY INTERFACE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov30
110
max
33
102.3
,/1066.13
,/5.486
,20
D
mq
mkg
mmN
CT
Hg
Hg
o
g
mHg
10105.1 s
0.0 0.5 1.0 1.510
-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
Reflectivity
Qz, A-1
T=20oC
theory: H2O s=3.9 A
theory: Hg s=1.5 A
ggs
/ln
2
max2
g
qTkB
D
XRR: BURIED INTERFACES
Page 31
J.F.L. Duval et al., Phys. Rev. Lett. 108, 206102 (2012)
Ionic spatial distribution at polarised mercury surfaces
Reflectivity e-density profile
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
Electrolytes
LiBr, LiCl and MgSO4
XRR: BURIED INTERFACES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 32
Decay of correlations in inhomogeneous fluids
K. Nygård & O.Konovalov, Soft Matter 8, 5180 (2012)
Ludox SM-30 SiO2 colloids:
Average diameter D0 = 10.3 nm
Polydispersity ΔD/D0 = 0.21
Debye length κ-1 = 3.4 nm
Bulk volume fraction ϕ = 0.18
fits with the stratified fluid model
the number density profile model
silica concentration profiles C(z)
d/D0
wavelength
ξ/D0
decay
z0/D0
position
air 1.32 ± 0.03 0.99 1.19 ± 0.02
wh 1.38 ± 0.07 0.99 1.46 ± 0.02
h 1.39 ± 0.03 1.27 1.11 ± 0.02
bulk 1.34 0.79
z0 d
D0
2
0
22 ss mm
SURFACE SCATTERING ON MEMBRANES MIMICKED WITH LANGMUIR METHOD
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 33
Control
area per molecule
(i.e. surface pressure)
temperature
phase transition:
gas – liquid – crystal
subphase
(water)
sample molecules in solvent
Wilhelmy plate
ai=2 mrag
foot print at 100 mm beam is 50 mm
XRR: LIPID MONOLAYERS ON WATER, SOL AND GEL SURFACE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
34
Glycerol
backbone
Hydrophilic
headgroup
Hydrophobic carbon
chains
Montmorillonite
Used as additive in many industrial
processes
The Mineral
- Phyllosilicate
- Disc shaped nano particles
- Surface area ~400 m2/g
- Charge deficiency of 0.7 / unit cell
- Charging: surface , edges
- With water: gives clear and colourless
dispersions and gels
The Gel
- Thixotropic, highly viscous
- Ionic bonds, not affected by temperature
- Gel Formation at concentrations < 1% in
water
~ 1 nm
~100 nm
I) Gelation of clays
After some hours:
Gel formation – House of cards
Dispersion
Hydratisation
Dry: Aggregated
ParticlesSol
Water
DSPC
DPPA
II) Phosholipids
Struth B., et.al. Phys. Rev. Let., 88, 25502, (2002)
XRR: LIPID MONOLAYERS ON WATER, SOL AND GEL SURFACE
Page 35
0.0 0.1 0.2 0.3 0.4 0.5 0.6
1E-8
1E-6
1E-4
0.01
1
Re
fle
ctivity
Qz (Å
-1)
Pure water sol and gel
DSPC layer at the water surface
DSPC layer at the sol surface
DSPC layer at the gel surface
•Identical roughness of free water, sol and gel surfaces
•Lipids form stable monolayers on water, sol and gel
•Attractive electrostatic interactions between the anionic mineral
particles and the zwitterionic lipid headgroup
•These interactions influence the lateral lattice of the monolayer Struth B., et.al. Phys. Rev. Let., 88, 25502, (2002)
~ 1 nm
~100 nm
Montmorillonite
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
XRR: C-CADHERIN INTERACTION WITH A MEMBRANE MODEL
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 36
• Cadherins extend over 230Å. That is shorter than
cadherin length : cadherin may be curved
• High density at large distance : parallel interactions ?
0,0 0,1 0,2 0,3 0,4 0,5
1E-9
1E-8
1E-7
Data
Fit
Ni-NTA-DLGA monolayer
X-R
ay R
efl
ecti
vit
y *
q4
Momentum transfer Qz (Å
-1)
0,0 0,1 0,2 0,3 0,4
1E-10
1E-9
1E-8
1E-7
Data
Fit
Momentum transfer Qz (Å
-1)
X-R
ay R
efl
ecti
vit
y *
q4
C-Cadherin bound to Ni-NTA-DLGA monolayer
0.35 0.40 0.45 0.50250
200
150
100
50
0
water
lipids + C-cadherin 1-5
lipids
Dis
ta
nc
e t
o t
he
ia
r-w
ate
r i
nte
rfa
ce
(Å
)
Electronic density (e-.A
-3)
L. Martel, et. al., J. Phys. IV France, v.12, 365 (2002)
Ca influence
Initial state After EGTA After Ca2+
1) After injecting proteins in the
subphase, a homogenous layer
is obtained in 4 hours
2) The decrease of bound
proteins after adding chelates
divalent ions EGTA is
interpreted as a partial
dissociation of adhesive dimers
3) Subsequent addition of
calcium restores the dimers
MEMBRANE DISCRIMINATION BY ANTIMICROBIAL PEPTIDES : MOLECULAR BASIS
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 37
erythrocyte membrane bacterial cell membrane
A.M. peptide
hydrophobic
interaction
electrostatic interaction
hydrophobic interaction
Zwitterionic phospholipids CholesterolAcidic phospholipids
A bacterial cytoplasmic cell membrane was
mimicked with the negatively charged lipids
DiPalmitoyl-PhosphatidylGlycerol (DPPG)
C38H75O10PNH3, MW=740 g/mol.
A mammalian cell membrane was
mimicked with the zwitterionic lipid
DiPalmitoyl-PhosphatidylCholine (DPPC)
C40H80NO8P, MW=734,1 g/mol.
Antimicrobial frog skin peptide –Peptidyl-GlycylLeucine-carboxyamide (PGLa)
21 amino acid residues : H2N-GMASKAGAIAGKIAKVALKAL–COOH
4 résidus chargés positivement (Lysine), MW=1969 g/mol
BENDING RIGIDITY (k) FROM GI DIFFUSE SCATTERING
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 38
4
||
2
||
||||
1
qqg
Tk
Aqzqz B
kg D
S. Mora et al., Europhys. Lett., v. 66, p. 694 (2004)
k
gCOQ
0.1 1 10 10010
-3
10-2
10-1
100
g=30 mN/m
g=10 mN/m
g=1 mN/m
g=0.1 mN/m
T=300K
QC
O ,
A-1
k, in kBT
Capillary waves -> height fluctuation spectrum
determided by
the surface energy (g)
associated with the deformation modes (k)[Helfrich, Z. Naturforsch., 28c , 693, (1973)]
qZ
βα
I0 I
qX
||||||2
22
rq)(r(0)
||
2
1,0
2
1,0
1r
)(~
izzq
zq
z
scin
eed
eqttd
d
z
zs
MEMBRANE DISCRIMINATION BY ANTIMICROBIAL PEPTIDES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 39
0.1 110
-10
10-9
10-8
10-7
10-6
10-5
10-4
I/I 0
, deg
Rigidity k kbT)
@ =30mN/m
< c
Rigidity k kbT)
@ >40mN/m
c
DPPG 55 5 145 5
DPPG+PGLa 27 5 20 5
Bending rigidity of the DPPG
membrane decreses upon
insertion of the antimicrobial
peptide PGLa
ai=0,022°, ac=0,0245° @ 22.5 keV
beam size 15 mm
Phospholipid monolayer at hexadecane-water interface
Bending Rigidity (k)
DPPG , =30mN/m
DPPG+PGLa , =30mN/m
DPPG , =40mN/m
DPPG+PGLa , =50mN/m
g = 55mN/m – , c=10:1
E. Saint Martin et al., Thin Solid Films, v.515, p.5678, (2007)
qZ
βα
I0 I
qX
Beam travel path 70 mm
transmission ~20% (22keV)
oil
water
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 40
Surface structure of sterically-stabilised ferrofluids
Rosensweig instability
FERROFLUID SAMPLES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 41
0 50 100 150 200 250
D (Å)
CORE SIZE
DISTRIBUTION
(SEM, TEM, XRD)
24 Å100 ÅFe3O4
magnetiteFe3O4 core
stabilizing agent:Na oleateoleic acid
=
water
Concentration C= 2 and 7 % vol.
Surfactant – sodium oleate
(C18H33NaO2) double layer
WATER-BASED FERROFLUID
200 Å
tetradecane
Tetradecane CH3(CH2)12CH3
Surfactant – oleic acid (C18H33OOH)
single layer
Concentration C= 13 % vol.
OIL-BASED FERROFLUID
150 Å
XRR, GISAXS, GID, FLUORECENCE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 42
Oil-based Ferrofluid
3-5 nm
30-40 nm
bulk
10 nm
2-2.5 nm
10-25 nm
bulk
3-6 nm
A. Vorobiev, et al., Phys. Rev. E 79, 031403 (2009)
inte
rfac
e
Aqueous Ferrofluid
0.00 0.02 0.04 0.06 0.08
10-1
100
101
102
103
flu
ore
sce
nce
yie
ld
Qz (Å
-1)
WATER FF
OIL FF
LBL=5nm
Fe
0 100 200 300 4000
2
4
6
8
10
12
ρ(1
0-6
Å-2
)
SLD [10−6 Å−2]
magn. core Fe3O4 40.5
surfactant C18H34O2 8.5
water H2O 9.5
FF bulk 10.0
Depth [Å]
0 100 200 300 400 500 600
0
2
4
6
8
10
12
rho,
10
-6
z, Å
ρOIL
ρBULK
Depth [Å]
SLD [10−6 Å−2]
magn. core Fe3O4 40.5
surfactant C18H34O2 8.5
liq. carrier C14H30 7.5
ρ(1
0-6
Å-2
)
Obtained model of the ferrofluid interface
GISAXS Fluorescence
Surface structure of sterically-stabilised ferrofluids
LANGMUIR TROUGH FOR LIQUID-LIQUID INTERFACE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 43
Air/oil interfaceOil/water interface
Movable barrier
X-ray beam
Barrier
air
water
hexadecane
XRR: BURIED INTERFACES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 44
22222 |]cos|1[|]/)(|1[ hrrE owowowsosw ggggg D
)cos1( rhParticle immersion:
Solid-water contact area: hrA 21
Missing oil-water area: 22
2 sinrA
Young’s equation: ggg cosowswso
Binding energy: owswso AAE ggg 21 )( D
water
oil
gow
gsw
gso
rh
solid
Nanoparticles as surfactants: contact angle & binding energy
BURIED INTERFACES
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 45
Formation and Ordering of Au-NPs at the Toluene-Water Interface(chemical reactivity at the liquid-liquid interface)
M.K. Sanyal et al., J. Phys. Chem. C, v. 112, 1739 (2008)
cluster-cluster separation
d1=180 Å
particle-particle separation
d2 = 34 Å
Each cluster consists of
13NPs with Ø 12 Å &
11 Å thick organic layer
3.2 h
4.7 h
6.1 h
4.2 h3.7 h
5.2 h
XRRGISAXS
Tim
e af
ter
reac
tion
initi
atio
n Triphenylphosphine gold chloride
in the toluene
&
Tetrakishydroxymethylphosphonium
chloride in the water
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 46
X-Ray Standing Waves (XSW)
Standing-Wave X-Ray Fluorescence
Grazing incidence X-Ray Fluorescence (TRXF)
STANDING WAVE FORMATION
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 47
A standing wave field formation
by the superposition of two plane
waves of wavelength λ and
intersection (=scattering) angle 2θ.
The standing wave period D is
QD
l
2sin2
0KKQ R
l
20 RKK
The larger 2θ angle the smaller period D
where
X-ray Standing Wave Techniques” M.J. Bedzyk, in Encyclopedia of
Condensed Matter Physics, edited by F. Bassani, G.L. Liedl, P. Wyder
(Elsevier, Oxford, 2005), Vol. 6, p. 330-341
XSW GENERATION BY CRYSTAL & TOTAL REFLECTION FROM MIRROR
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 48
nmSiDc 20)(
mirror
2
0
2
0)(
E
EEI
HSW
r
l
ccD
sin2
-5 0 5 100.00
0.25
0.50
0.75
1.00
Re
lative
Ph
ase
Re
fle
ctivity R
B (arc.sec.)
SW Nodal plane
SW Antinodal plane
Diffraction plane
Hrr 2cos21)(0
2
0
2
0
2
0
E
EC
E
E
E
EEI HHHSW
Incoming
wave
Bragg-reflected
wave
Interference of
incoming and
reflected wave
X-RAY STANDING WAVE FORMATION IN DIFFRACTION CONDITIONS
Page 49 5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
-5 0 5 100
1
Refle
ctivity
B (arc.sec.)
0
1
2
3
4-5 0 5 10
Ph=0.8
Ph=0.2
Ph=0.5
Norm
aliz
ed
Yie
ld
Ph=1
It describes the
position relative to the
diffraction planes
10 hP
Coherent position
dhkl
h’
Ph=h’/dhkl
)2cos(21 hh PfRRY Secondary radiation yield
COHERENT FRACTION AND COHERENT POSITION
Page 50 5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
-5 0 5 100
1
Refle
ctivity
B (arc.sec.)
0
1
2
3
4-5 0 5 10
fh=0
fh=0.3
fh=0.7
fh=1
Norm
aliz
ed
Yie
ld
It describes the
degree of ordering
in the system
10 hf
Coherent fraction
dhkl
Δh’
fh=cos(πΔh’/dhkl)
)2cos(21 hh PfRRY Secondary radiation yield
COHERENT FRACTION AND COHERENT POSITION
Page 51 5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
GIXF : GRAZING INCIDENCE X-RAY FLUORESCENCE (TRXF)
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 52
SUBSTRATE
a
)1(
fdFILM)2(
fd
detector
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
102
103
Pen
etr
ati
on
dep
th,
1/A
Grazing angle, a/ac αi / αC
Pen
etra
tion
dept
h,[Å
]
nf > ns
grazing angle
refle
ctivity
flu
ore
sce
nce
MONOLAYERS OF PHTHALOCYANINES AT AIR/WATER INTERFACE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 53
0.5 1.0 1.5 2.00.0
0.5
1.0
Flu
ore
sce
nce y
ield
, a.u
.
, mrad
Refle
ctivity
Sn Pc
Cu/Fe Pc
0.0
0.5
1.0
1.5
One fitting parameter
Me - A/W interface distance
Best fit at D=7 A
S. I. Zheludeva et al., Material Science and Engineering C 23 (2003) 567
E, keV
GIXF: SPECIFIC ION ADSORPTION AND SHORT-RANGE INTERACTIONS
AT THE AIR AQUEOUS SOLUTION INTERFACE
Page 54
V. Padmanabhan et al., Phys. Rev. Lett. 99, 086105 (2007)
ai nm-1
ai-1
(If/I e
)/(I
f/I e
) bulk
KCl 0.1M + KI 0.1M
CsCl 0.1M + CsI 0.1M
KCl 0.1M
depleted layer 3.77 A
elec > solv
dConcentration profiles
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov
So far: heavy elements (metal ions)
Technique:
metal multilayer support strong Bragg reflection
beam interference x-ray standing wave (XSW)
XSW induces element-characteristic x-ray fluorescence
angle-dependent XSW shape
elemental distributions
at near-Å resolution
New: biologically important „light“ elements S and P
Defined chemical position in biomolecules Parameterization:
z,
zj
jI fluo intensity
XSW
distribution element j
jz
js
center position (± 2 Å)
width (not below 10 Å)
SS
S
P
SP
Molecules:
- lipids
- saccharides
- proteins
STANDING-WAVE X-RAY FLUORESCENCE
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov55
Lipid Single Monolayers on Al oxide
Sulfoglycolipids (SGS)
abundant in nerve system and
thylakoids
SGS: S at tip of saccharide
headgroup (hg)
fit: sharp S distribution (s < 10 Å)
center set as zS= 0 (solid surface)
jISymbols: experiment. Solid lines: model
Multilayers: 20x(Ni/Al ), 20 nm period, surface: single crystal sapphire Al oxide terminated
Phospholipids
dominant lipid class in animals
DSPC: P in inner hg region
fit: zP = 4 ± 2 Å
different hg structure
Phospholipids + PEG lipids
5% PEG lipid, N = 114
fit: zP = 3 ± 2 Å
no PEG layer below
monolayer
DEPTH LOCALIZATION WITH NEAR-ANGSTROM PRECISION OF BIOLOGICALLY
IMPORTANT CHEMICAL ELEMENTS IN MOLECULAR LAYERS
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov56 E. Schneck et al., PNAS (2016)
CONCLUSION
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov57
gas-liquid
liquid-liquid
liquid-solid
Langmuir films
Complex fluids
Buried interfaces
- Surface structure of simple and complex fluids- Morphology and crystalline structure
of thin organic and inorganic films- 2D organization of molecules,
macromolecules and nano particles- Bio-mimetic systems & Bio-mineralization- Chemistry & Electrochemistry - Surfactants & ions ordering
Elements distribution
P, A, T
X-ray surface sensitive technique is a powerful tool to study broad spectrum of scienceat surfaces and interfaces
ACKNOWLEDGEMENTS
5-6/10/2016, XRM Workshop 2016, University of Twente, O. KonovalovPage 58
ID10 staff
Numerous collaborators and users
Thank you !
Yuriy Chushkin, Federico Zontone, Beatrice Ruta, Giovanni Li Destri, Karim Lhoste
Contact: Oleg Konovalov, [email protected]
J. Daillant & A. Gibaud, “X-Ray and Neutron Reflectivity: Principles and Applications”, Springer, 1999
M. Tolan, “X-Ray Scattering from Soft-Matter Thin Films” Springer, 1999
J. Als-Nielsen & D. McMorrow, “Element of Modern X-ray Physics”, John Wiley, 2001
J. Zegenhagen, A. Kazimirov, “The X-Ray Standing Wave Technique Principles and Applications”, World Scientific, 2013
I. K. Robinson and D. J. Tweet, Rept. Prog. Phys. 55, p.599 (1992)
J.Daillant, M.Alba, Rep. Prog. Phys. 63 1725–1777 (2000)
Further reading
If you are interested in this position, please apply on http://www.esrf.fr/Jobs
For further information please contact Diego Pontoni
([email protected]; +33(0)476 88 2817; +33 676 38 96 80)
ID10-SI END STATION: SCIENTIFIC APPLICATIONS
5-6/10/2016, XRM Workshop 2016, University of Twente, O. Konovalov60
• Surface structure of simple and complex fluids (colloid, gel, sol,…)
• Langmuir films, amphiphilic polymers and nano- particle at the air-water
interface
• Capillary wave and surface roughness
• Structure and growth of two dimensional crystals of molecules,
macromolecules and proteins
• Morphology and crystalline structure of thin organic and non-organic films
on solid substrates
• Phenomena at liquid/liquid and solid/liquid interfaces
• Cell membranes
• Shape, strain, ordering and correlation of crystalline nanostructures,
quantum dots and wires on substrates