hybrid organic-inorganic glasses inorganic chemistry = organic chemistry room temperature...
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Hybrid organic-inorganic glasses
inorganic chemistry = organic chemistry
room temperature
metal-organic precursors in organic solvents
a whole range of new materials from brittle glasses to plastic polymers
Hybrid organic-inorganic materials
Classification
based on the nature of interactions between organic and inorganic components
Class I
No chemical bond between components
only weak interactions
(van der Waals, hydrogen, electrostatic)
Class IIChemical bonds between components
strong interactions(covalent bonds)
Entrapping Grafting
NH SiO2N
NO2
O
O
O
Si
Si
Si
OO
O
O
O
OO
O O
NH2O2N
NO2
Si
O
O
O
Si
Si
Si
OO
O
O
O
O
O O
HO
O
Class I the organic molecule is trapped within the silica network
Si(OR)4
ROH
Si(OR)4
Si(OR)4
Si(OR)4
ROH
ROH
H2O
sol-gel precursorSi(OR)4
organic molecule
Solution(common solvent)
organic moleculetrapped in thesilica matrix
Hydrolysis-condensation
Class II : network modifier
OR
RO - Si - CH3
OR
Si-O-Si network + pending organic groups
-Si-CH3
OR
H3COR
Si-O-Si chains + side organic groups
Synthesis of hybrid organic-inorganic materials
R-Si-(OR)x + M(OR)n
metal alkoxideorgano-functionalalkoxide
Oxo-polymers
conventionalsol-gel route
organic templatesinorganic
building blocks
Class II : network formers
Si-CH=CH2
OR
OR
RO
Double polymerization process
[SiOx(OH)y]n
-[SiMe2O]-
inorganic
organic
Si > R Si < R
The size of both phases depends on the Si/R ratio
coordination saturation
slowly hydrolyzable complexing ligands
iOPrOPriH C3OPri OOCH CCH C3TiOPriPriOOPriOPriTiOOC3OOCOPriOPriPriOPriOPriOTiTiPriO3CHCHacetic acidacetylacetone
acetic acidacetylacetone
Chemically Controlled Condensation
Ti(OR)4 + x AcacH
Ti(OR)4-x(acac)x + x ROH
M
OH2
M
AcacH
molecularclusters
Stable sols
Gels
Precipitates
Complexation ratio x = acacH/Tiprevents condensation
Hydrolysis ratio h = H2O/Ti
favors condensation
Chemically Controlled Condensation
2 parameters
x
h
Ti12O16(OPri)16 Ti17O24(OPri)20Ti18O22(OBun)26(Acac)2
Ti(OR)4-x(acac)x
Molecular clusters Organic bridges
K.J. Shea, D.A. Loy, Acc. Chem. Res. 34 (2001) 707
Bridged Polysilsesquioxanes3(RO)-Si Si(OR)3
xerogel
aerogel
rigid bridge flexibe bridge
SSi(OCH3)3(H3CO)3Si
(H3CO)3Si Si(OCH3)3
Si(OCH3)3(H3CO)3Si ( )n
(n = 1-3)
triple bridge
Si(OCH3)3
Si(OCH3)3(H3CO)3Si
The pore size depends on the length of the bridge
Anisotropic silica
polarized light
Bruno Boury (ICG - Montpellier)
π-π stacking leads to anisotropic materials
ORMOCER
ORMOSIL
ORganically MOdified SILicate
ORganically MOdified CERamic
CERAMER
CERAmic polyMER
Hybrid Sol-Gel Coatings
Le dôme du
grand théâtre national chinois
est recouvert d’un revêtement auto-nettoyant
Beijing Zhongke Saina Glass Technology
Sol-gel coating
magnifying lens coated with an abrasion resistant hybrid coatingScratch resistant coatings on plastics
ABRASIL
Si - ORR
OR
OR
SiO2polymer
Modification of the glass surface tension
glass underatmosphericconditions
glass modifiedwith a
hydrophobiccoating
glass modifiedwith a
hydrophiliccoating
Antisoilingproperties
Antifoggingproperties
© INM - Saarbrücken - Germany
Antifogging and antisoiling glass coatings
hydrophobic coatings on windshields
Hybride PDMS + TEOS : « sliding effect »
Hybride PDMS + TEOS + FAS : against rainFAS = CF3-(CF2)7-CH2-CH2-Si-(OCH3)3
HO-Si OR
R-(CH2)n-Si-OR OR
R = hydrophobic group : CF3, CH3, …
Central Glass Japon
Stainless steel without coating
Stainless steel with an
abrasion resistant
fluorinated hybrid coating
Sol-gel hydrophobic coatings
G. Schottner, Chem. Mater. 13 (2001) 3422
Hhydrophilic and photocatalytic coatings
Two layers :
SiO2 : hydrophilic, scratching resistant
TiO2 : photocatalytic effect under UV irradiation
Thermal treatment at 600°C
© CGC Ltd.© CGC Ltd.
‘anti-mist’ coatings
Central Glass - Japon
To avoid moisture condensation on a cold surface
SiO2-ZrO2
SiO2 / ZrO2 colloïdal + top-layer SiO2 ou
Gel = isocyanate + ethylene oxide/propylene oxide + PEG + PC polyol
dépôt par spin-coating + traitement thermique (@150°C); ép. 20µm
© CGC Ltd.
before after
Getty Museum - Los Angeles
Cathedral of Pragua Protection of the mosaic by an hybrid coating
Nanopatterning via
sol-gel embossing
soft hybrid sol-gel films
Nano-patterned films
produced by embossing a hybrid coating
Hybrid coating
Periodic microstructure leading to a gradient in the refractive index
coated
non-coated
‘ lotus ’ effect
Filling composites for dental applications
Definite & Admira resins(Fraunhofer ISC - VOCO GmbH)
Reduction of polymerization shrinkage
sol-gel optics
bulk pieces
no crack or shrinkage upon drying (hydrophobic organics)
easily shaped materials (molding, polishing)
nano-composite = transparency
Matech
sol-gel optics
Organic dyes in a silica matrix
fluorescence - laser - NLO - photochromism
Crystal glasses with
colored hybrid coatings
Fraunhofer Würzburg
Coating on glasses
hybrid coating + organic dyes
Easily recyclable colored bottles
• Organic dyes large choice of colors (marketing !) pigments can be burned off before recycling
• Hybrid coatings improved mechanical properties of bottles© Asahi-Kirin
Si(OCH3)4 + Ti(OC3H7)4
CH2=CH-Si(OC2H5)3
methacrylate-Si(OC2H5)3
UV and curing
organic dyes
Sol-gel dye lasers
Organic dyes are trapped
within sol-gel silica matrices
(solid ≠ solution)
Organic dyes cover the whole visible range
Tunable lasers
N O N
CO2H
Rhodamine 640
O O
CH3
HOCoumarine 4
LASER dyes
singlet triplet
electronic energy levels of fullerene
C60
Reverse Saturable Absorption
the excited state absorption is stronger than the ground state absorption
C60
Reverse Saturable Absorption
the excited state absorption is stronger than the ground state absorption
Input energy (J)
tran
smis
ssio
n
absorption increases with the input power
Fullerene C60
Sol-gel devices
C60 fullerenes are not soluble
small amount of C60
aggregation
Functionalization of C60 grafted onto silica
P. Innocenzi et al. Carbon 38 (2000) 1653
nonlinear hybrid C60-silica coated lenses
Optical limiters
E
Non linear optic
alignment of NLO molecules by a external field
Second Order NLO
Induced polarisation : P = P0 + (1)E + (2)E2 + (3)E3 + …
electro-optic modulation
frequency doubling
frequency mixing
Non centro-symmetric materials
electrons AD
Non symmetric moleculesNO2H2N
H3C
heating plate
10 kV
corona poling
methyl nitro aniline
Sol-gel entrapment poling relaxation
relaxation short lifetime
Covalent grafting increases dye concentration
prevents relaxation
NH Si(OEt)3
NO2
O2NN
N
OHN
O
OHN
O
O2N
Si(OEt)3
Si(OEt)3
d33 = 150-200 pm/V
High non resonant Second Harmonic Generation
Photochromic glasses
switching time ≈ 1 hourHydrophilic silica
Spiro oxazinecolorless blue
hydrophilichydrophobic
N O
N
N+
N
O-
UV
, visible
hydrophilic/hydrophobic walls of the nanopores
RO ORSi
OR
OR
RO CH3Si
OR
OR
+
Hybrid precursors
Switching time from 1 second to 1 hour Protavic - France
Si Si Si SiSi
SiSiSiSi
Si
Si
SiSi
Si Si Si Si SiSi
Si
Si
Si
CH3 H H
HH
HHHHHHH
HHH
HH
Si
HH
CH3
CH3CH3
CH3N
O
N
NO
N
Microencapsulation of liquid crystal droplets dispersed in sol-gel films
Glass plate transparent electrode (ITO)
LC droplet (neff)
Silica gel film
OFF : light scattering (opaque)ON : applied voltage - alignement of LC (transparent)
Merck - Germany
safe and inert UV-filters that do not penetrate the skin
Organics undergo photodegradation
free radicals
1
Encapsulated UV-Filters
encapsulation of organic filters in hollow silica spheres
Merck
aqueous suspension containing ≈ 40% nanoparticles