0 0.01 0.02 0.03 0.04 0.05
Eredeti BTS 1x kezelt BTS 2x kezelt
∆n
Víz Etanol Hexán
0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02
Víz Hexán
∆n
Eredeti OT-AuNR 1x kezelt OT-AuNR 2x kezelt
Optical properties and sensorial application of Optical properties and sensorial application of
surface modified
surface modified z z inc peroxide thin layers inc peroxide thin layers
Dániel Seb ő k
1, Imre Dékány
21 Department of Physical Chemistry and Materials Sciences, University of Szeged
2 Institute of Medical Chemistry, Faculty of Medicine, University of Szeged, Hungary i.dekany@chem.u-szeged.hu
Curve smoothing by polynomial fitting
Curve smoothing by polynomial fitting Refractive index measurement, calibrating by QCM Refractive index measurement, calibrating by QCM Adsorption isothermsAdsorption isotherms
AIM OF THE WORK AIM OF THE WORK
We have prepared
We have prepared ultra thin films from metal oxide semiconductor (ZnOultra thin films from metal oxide semiconductor (ZnO22)) as inorganic colloids and anionic as inorganic colloids and anionic polyelectrolyte (poly(styrenesulfonate), PSS) using the layer
polyelectrolyte (poly(styrenesulfonate), PSS) using the layer--by layer (LbL) preparation process. The optical by layer (LbL) preparation process. The optical properties
properties –– refractive index, layer thickness, porosity etc.refractive index, layer thickness, porosity etc. -- of the hybrids were calculated of the hybrids were calculated by a novel method by a novel method (fitting of analytical curves)
(fitting of analytical curves) by reflectance measurementsby reflectance measurements. Adsorption properties were studied by quartz crystal . Adsorption properties were studied by quartz crystal microbalance (QCM) and reflection spectroscopy.
microbalance (QCM) and reflection spectroscopy.
These films are useful for sensorial applications, because their
These films are useful for sensorial applications, because their index of refraction is strongly dependent from the index of refraction is strongly dependent from the environment.
environment. The surface of theThe surface of the nanohybrids was modifiednanohybrids was modified by by butylbutyl--trichlorosilane (BTS) and gold nanoparticlestrichlorosilane (BTS) and gold nanoparticles covered by octanethiol
covered by octanethiol (OT(OT--AuNP) AuNP) to increase their hydrophobicity and to increase their hydrophobicity and selectivityselectivity to ethanol and hexane vapourto ethanol and hexane vapour. .
THIN FILM PREPARATION PROCESS THIN FILM PREPARATION PROCESS
We have prepared ultra thin films from metal We have prepared ultra thin films from metal
oxide semiconductor ZnO
oxide semiconductor ZnO22 as inorganic as inorganic colloids and anionic polyelectrolyte PSS colloids and anionic polyelectrolyte PSS
using the layer
using the layer--by layer by layer (LbL)(LbL) preparation preparation process.
process. Surface modificationSurface modification were carried were carried out by dropping the BTS or OT
out by dropping the BTS or OT--AuNP AuNP hexane solution.
hexane solution.
THIN FILM CHARACTERIZATION THIN FILM CHARACTERIZATION
The optical properties
The optical properties –– refractive index, layer thickness, refractive index, layer thickness, porosity etc.
porosity etc. -- of the hybrids were calculated of the hybrids were calculated by a novel method
by a novel method (fitting of analytical curves)(fitting of analytical curves) by by reflectance measurements
reflectance measurements. Adsorption properties . Adsorption properties were studied by quartz crystal microbalance (QCM) were studied by quartz crystal microbalance (QCM)
and and reflection spectroscopyreflection spectroscopy. .
SENSORIAL APPLICATION SENSORIAL APPLICATION
Adsorption properties were studied by Adsorption properties were studied by
quartz crystal microbalance (QCM) quartz crystal microbalance (QCM)
and reflection spectroscopy.
and reflection spectroscopy.
ACKNOWLEDGEMENT ACKNOWLEDGEMENT
The presentation is supported by the European Union and co
The presentation is supported by the European Union and co--funded by the European Social Fund, funded by the European Social Fund, project number: T
project number: TÁÁMOPMOP--4.2.2/B4.2.2/B--10/110/1--20102010--0012.0012.
Original HEXANE
WATER ZnO2 / PSS
S S
S SS
SS S
S S
S S S
S SS
SS S
S S S S
S S SS
SS S
S S S
Thin film preparation by LbL method Surface modifi
Thin film preparation by LbL method Surface modification Changed adsorptional propertiescation Changed adsorptional properties
Solid State Model (Geometrical Model)
Solid st. / Pore
(Effective Medium Model)
Wave Propagation (Wave Optics Model)
3 component
Bruggemann-model Complex Amplitude method Two-ray Interference
2 2 2 2 2 2 4 cos
' (1 ) 2 '(1 ) cos e
R
I a r r r rr r πn d β
λ
⋅ + − + −
≃
Refractive Index Refractive Index
Layer Thickness Layer Thickness Describing the reflection properties with 3 models
Describing the reflection properties with 3 models Applying the result Applying the result n(n(λλ), d), d
19 19.5 20 20.5 21 21.5
690 695 700 705 710 715 720 725 730
Wavelength (nm)
Reflection
600 605 610 615 620 625 630
0 500 1000 1500 2000 2500
606 608 610 612 614 616 618 620 622 624
0 500 1000 1500 2000 2500
Water Ethanol Hexane
Original BTS 1X modified BTS 2X modified
Original
Octanethiol 1X Octanethiol 2X
Water Hexane -20
0 20 40 60 80 100 120 140
0 200 400 600 800 1000 1200
Time (s)
C (ppm), dm/A (ng/cm2)
-0.007 -0.002 0.003 0.008 0.013 0.018 0.023 0.028
dn (RIU)
c (ppm) QCM
OceanOptics
0 2 4 6 8 10 12 14 16 18
0.00 0.20 0.40 0.60 0.80 1.00
Relativ vapor pressure
Specific adsorbed amount (nmol/cm2)
metanol etanol propanol toluol hexan
BTSBTS
Octanethiol Octanethiol
