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