jan perlich tu münchen, physik-department ls e13, james-franck-str. 1, d-85747 garching
DESCRIPTION
Nanostructured Films of Selfencapsulating Inorganic-Organic Hybrid Materials DFG-SPP 1181 NANOMAT. Jan Perlich TU München, Physik-Department LS E13, James-Franck-Str. 1, D-85747 Garching. Mine Memesa Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz. - PowerPoint PPT PresentationTRANSCRIPT
Jan PerlichTU München, Physik-Department LS E13,
James-Franck-Str. 1,D-85747 Garching
Mine MemesaMax-Planck-Institut für Polymerforschung,
Ackermannweg 10,D-55128 Mainz
Nanostructured Films ofSelfencapsulating Inorganic-Organic
Hybrid Materials
DFG-SPP 1181 NANOMAT
PD Dr. P. Müller-Buschbaum Prof. Dr. J.S. Gutmann
Sebastian Nett
Yajun Cheng
Calcination
Ordered crystallites
Ultra-thin films
Spin coatingAmphiphilic
PS-b-PEO
+Sol-gel chemistry
Titan(IV)oxid sol-gel precursor
Micelles in solution
0,00 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,09 0,10
0,00
0,01
0,02
0,03
0,04
0,05
0,06
0,07
0,08
0,09
0,10 0,90
0,91
0,92
0,93
0,94
0,95
0,96
0,97
0,98
0,99
1,00
W.(TTIP)
Ternary phase diagram
Goal: Intelligent, nanostructured materials Use of functional inorganic materials TiO2 (crystalline) photocatalysis
photovoltaicY.-J. Cheng, J. S. Gutmann, JACS, 128, 4658 (2006).
Basic materials (before SPP1181)
Properties of prototype solar cells
PS-b-PEO and PMMA-b-PEO as amphiphilic block-copolymers
P3HT / N3 dye / D50 TiO2
0,0
1,0
2,0
3,0
4,0
5,0
6,0
350 400 450 500 550 600 650 700
Wavelengh [nm]
EQ
E /%
PS-b-PEO (19k/6k)~ 20nm particles
PMMA-b-PEO (24k/18k)
~ 50nm particles
P3HT / N3 dye / D20 TiO2
0,0
3,0
6,0
9,0
12,0
15,0
18,0
350 400 450 500 550 600 650 700
Wavelengh [nm]
EQ
E /%
FTOTiO 2
Sub stra te
PHT
Au o r Ag PHT= regioregular Poly(3-hexylthiophene)Dye = cis-(SCN)2 bis (2,2’ bipyridyl-4,4
-dicarboxylate) ruthenium(II)
Can we improve or replace the blocking layer?
Yes, use different polymer! Si
CH3
CH3
O
O n
PEOm
C
CH3
H3C
CH3
O
PDMS
TiO2 (amorph)
Substrate
PDMS TiO2 (krist.)
Substrate
PDMS
400°C
Inert gas
TiO2 (cryst)
Substrate
SiOC
1200°C
Inert gas
Substrate Substrate
400°C
Inert gas
exposed TiO2 (cryst.)
1200°C
Inert gas
Plasmaetch
Substrate
Goal: Integrated self-encapsulation
Central problem: Quality of barrier layer
1.) Pre-test with „conventional“ nanoparticles
Covering of “conventional” titania nanoparticles with
PDMS
Subsequent etching
2.) Synthesize a suitable PDMS block copolymer
How do we test our integrated approach?
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 150
10
20
30
40
50
60
70
80
Film
th
ickn
ess
(n
m)
Etching time (min)
3 min 45 sec
7 min 30 sec
15 min
Plasma etching of PDMS coverednanoparticles
w/o nanoparticles
w/ nanoparticles
Photoluminescence of titania nanoparticles
350 400 450 500 550 600 6500
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
/nm
inte
nsi
ty/a
.u.
TiO2 nanoparticles+PDMS after calcination
TiO2 nanoparticles+PDMS before calcination
bareTiO2 nanoparticles
Considerable increase in the intensity of the peak after etching.
398nm,470nm- self-trapped excitons
localized on TiO6 octahedra
431nm- surface defects
Characterization of Samples
Methods Extracted Information X-Ray Reflection (XRR) Film thickness
Scanning Electron Microscope (SEM) Morphology (real space)
Atomic Force Microscope (AFM) Topography (real space)
Grazing Incidence Small Angle Morphology
X-Ray Scattering (GISAXS) (reciprocal space)
Synchrotron beamline BW4, DESY HASYLAB
Microfocussed beam size 30 x 60 m2
Wavelength = 0.138 nm
Sample detector distance d 2 m
Incidence angle i 0.7 deg
Further Options: SAXS, GIUSAXS, NR & SANS
UV/Vis Spectroscopy, Photoluminescence (PL)
Scattering under grazing incidenceGISAXS
Non-desctructive structural probe
NO special sample preparation required
Yields excellent sampling statistics
Averages over macroscopic regions to provide information on
nanometer scale
Sensitive to surfaces and selective to materials
investigation of structures in the m- to nm-scale
Extracts information about: object geometry, size
distributions & spatial correlations
GISAXS of nanocomposite films
Detector scans Horizontal cuts c (PEO) Horizontal cuts c (TiO2)
Before calcination
After calcination
Ordered clusterednanoparticles
Further orderingof nanoparticles
Calcination
Substrates w/ ordered nanoscale roughness
Detector scans Horizontal cuts c (TiO2) Horizontal cuts c (TiO2)
ITO w/o film
ITO w/ film
Glass w/film
Glass w/o film
SEM: bare ITO
AFM: bare ITO AFM: ITO w/ filmglassITO
GISAXS of plasma etched samples
Detector scans Horizontal cuts c (PDMS) Horizontal cuts c (TiO2)
I: O2 plasma etch, 15 min
(Si/PDMS(TiO2)
II: O2 plasma etch,
3:45 min (Si/PDMS(TiO2))
III: IV after calcination
IV: as prepared
(Si/PS-b-PEO(TiO2))
IIV III II
Data treatment & simulation
Fixed resolution peak
2. Structure peak
1. Structure peak
1. Vertical & horizontal cuts from measured 3D data
2. Mathematical model 2D fit of horizontal cuts
3. Physical model Input of extracted parameters of mathematical fit
2D fit and 3D simulation of scattering pattern
Results of GISAXS
Successful preparation of desired morphologies of ordered nano-
composite films establishment of preparation
Working PDMS plasma etch process Pre-test accomplished
Calcination induces further ordering
GISAXS investigation of ordered nanocomposite films on substrates
with ordered nanoscale roughness
AFM & SEM results are in good agreement with GISAXS
PDMS synthesis: PDMS-b-PEO
Synthetic approaches in literature
1. Coupling via hydrosilylation (Hüsing, Mascos) good yield for low molecular weights (Mw) for suitably high Mw: Yield ~ 2-5% (due to cleaning)
2. Sequential polymerization in presence of crown ethers (Meier)
CH3
O
On
O-
Si
O
Si
O
Si
OCH3
CH3
CH3H3C
H3C
H3C
Crown ether
PDMS did NOT grow in desired extent
in THF
Own approach: Coupling of anionic polymerization and ATRP
Cl Si
CH3O
O
CH3
CH3
CH3
Br
1. Anionic polymerization of PDMS stopped by
2. Polymerization of PBMA carried out by ATRP
THF, RT, CuBr and ligand N
H3C
H3C
N
CH3
N
CH3
CH3
Si
CH3O
O
CH3
CH3
CH3
CH2
C
CH3
H3C
CH3
Si
CH3
CH3
O Si
CH3
CH3
O
n
C
CH3
C O
O
CH2
m
We have block with presence of homopolymers.
HPLC graphs of PDMS-b-PBMA
UV measurement
Light scattering measurement
Better attachment of ATRP initiator
L. Bes, K. Huan, E. Khoshdel, M.J. Lowe, C. F. McConville, D.M. Haddleton, Eur. Poly. J. 39, 5-13 (2003)
ABA triblock copolymers synthesized with different molecular weights
Next step: Attachment of ATRP initiator by esterification of a carbinol
group at the end of PDMS with 2-bromo-iso-butyryl bromide
Then PMMA polymerization by ATRP
PDMS-CNO and PEO-OH
Si
Cl
N
C
O
Si
N C O
C
CH3
H3C
CH3
Si
CH3
CH3
O Si
CH3
CH3
O
n
C
CH3
H3C
CH3
Si
CH3
CH3
O Si
CH3
CH3
O-Li+
n
O
K
O
THF
O
O
OH
n
O
O
OH
nSi
N C O
C
CH3
H3C
CH3
Si
CH3
CH3
O Si
CH3
CH3
O
n
THF, 35°C
Catalyst: dibutyltin dilaurate
THF, reflux
Sn2+
O O-
O-O
dibutyltin dilaurate
No block!
K. Kim, K. E. Plass, A. J. Matzger JACS, 127, 4879 (2005)
1.
2.
3.
Results of synthesis
Desired block hard to be synthesized with shown approaches
Coupling with reactive end remains problematic
Preferred route:
Coupling of anionic with ATRP
Different topologies (bottle brush)
Outlook
Characterization
Setting up process cell GISAXS in-situ investigation of templated hybrid films
Reinforced simulation
Synthesis
PDMS-b-PEO by coupling of end groups (catalyst)
PDMS-b-PHEMA by attachment of ATRP initiator
Material
PDMS barrier layer properties (characterization)
Optimized etch conditions & applied substrate materials
Network
GISAXS for other projects sharing resources
Developing new ideas