Amorphous Silica

Silicon: from periodic table to biogenic silica C. Bonhomme, Professor Sorbonne University

1 General properties

2 Silicon

Z = 14

Si: 1s2 2s2 2p6 3s2 3p2 Si4+: 1s2 2s2 2p6

(Si) = 1.8

second natural abundance on earth (28%)

-1 atomic mass: 28.085 g.mol J. J. Berzelius (1823) 28Si (92.27 %) silica (SiO2) 29Si (4.68 %) silicates (aluminosilicates...) 30Si (3.05 %) 3 From SiO2 to Si

electronic Si «diamond» like structure SiO2 cubic structure a= 5.4307 Å HCl

SiCl4,SiHCl3 reduction 1000°C

Si (98-99 %) Si > 99.9999 %

metallurgical Si

0.5 to 1 million tons FP: 1410°C per year! BP: 2680°C

wafer (100-300 mm) 4 Si: chemical bonding

Si – H 1.48 Å Si – Si 2.35 Å SiO2 Si – N 1.74 Å Si – O 1.61 Å Si – F 1.55 Å

Si –Cl 2.01 Å three Si tetrahedra Si –Br 2.15 Å

Si – C 1.80 Å (NH4)2SiF6 SiF4

silicones

5 Crystalline and amorphous silica

6 SiO2 polymorphs

Stishovite

Coesite

synthetic quartz

High High

Cristobalite

quartz 7 Tridymite X-Ray diffraction l ≈ 10-10 m = 1 Å X-rays are waves: 1913 Polymorph (density)

Low Quartz (2.65) trigonal High Tridymite (2.28) hexagonal High Cristobalite (2.21) cubic Coesite (2.93) monoclinic W. Röntgen Stishovite (4.30) tetragonal (1845-1923)

M. von Laue (1879-1960) in: Phys. Rev., 1923

W. H. Bragg (1862-1942)

W. L. Bragg (1890-1971) 8 «Other» quartz

Amethyst Citrine

Agate Rose quartz Smoky quartz 9 Various crystallographic structures

Quartz Cristobalite

Tridymite

SiO6 octahedra!

Stishovite (6-fold coordination!) Coesite 10 Amorphous silica

mineraloids

Lechatelierite a pure silica glass (rare) Obsidian

Newbury Crater, Oregon

Fulgurite obsidian arrows lightning on sand! Trinitite: start july 16, 1945! and scalpels 11 Hydrated silica: Opals

close-packed array of SiO2 spheres 0.15 to 0.4 mm

colloidal crystals

silica nanoparticles in an amorphous hydrated silica matrix SiO2,nH2O 12 Other opals

J.V. Sanders, 1980

spheres of two different sizes!

concoidal fracture (like glass) 13 Nuclear Magnetic Resonance (NMR)

W. Pauli, Physique 1945 "for the discovery of the F. Bloch, E. M. Purcell, Exclusion Principle, also called Physique 1952 K. Wüthrich, Chimie 2002 the Pauli Principle" "for his development of NMR "for the development of new spectroscopy for determining methods for nuclear magnetic G. Uhlenbeck, S. Goudsmit the three dimensional structure precision measurements and of biological macromolecules in "pères du spin" discoveries in connection solution" therewith"

I. I. Rabi, Physique 1944 "for his resonance method for recording the magnetic properties of atomic nuclei"

R. R. Ernst, Chimie 1991 "for his contribution to the development of the methodology of high resolution NMR spectroscopy"

P. C. Lauterbur, P. Mansfield, Médecine 2003 "for their discoveries concerning 14 magnetic resonance imaging" NMR basics

B (~15T) 0 DmI =  1 ^m = g h Î mI=-1/2

DE = ghB0 / 2p magnetic spin angular momentum m =+1/2 n0=gB0/2p moment I

gyromagnetic ratio Larmor frequency!

E = - m . B

Boltzmann equation My Curie law M

2 2 N g h B0 I(I+1) M= 12 p2 kT

B (RF): on resonance! Man, Encyclopedia of analytical 1 chemistry, 2000, 12228. 15 8H 8H a) CPMAS, R=12kHz, T b) CPLGMAS, R=12kHz, T

DCP=5,20,1kHz DCPLG=3,10,1kHz

29Si chemical shifts

29Si chemical shift -6 -4 -2 0 2 4 6 -6 -4 -2 0 2 4 6 M Dfrequency (kHz) T frequency (kHz) Q

(ppm) 20 R 0 R - 20 - 40 R - 60 - 80 O -110 R-Si-R R-Si-O O-Si-O O-Si-O O O O O

B0 signe des valeurs propres ! Si1 rotor axis m= 54,7° Si2

Si1 Si1 Si2 silsesquioxane

Si1 rHSi2,5150,002Å

rHSi=4,725 or 6,270 or 5,1020,002Å

silsesquioxane modèle

MAS 29Si NMR 16

silsesquioxane fonctionnalisé 4- and 6-fold coordinated Si atoms

SiP O an example: Si-O-P bonds 31 2 7 P tetragonal

tetrahedron SiO4 Si2 O Si5O(PO4)6 SiP O O 5 2 7 Si3 4 monoclinic 1 Si P O 2 2 SiP O O3 SiP2O7 2 7 monoclinic 2 cubic

Si1

-30 -40 -50 -60 -70 ppm octahedron SiO 6 6 Si 29 Si Si Si Si P 4

P Si

-100 -120 -140 -160 -180 -200 -220 C. Coelho, Paris 6 ppm 17 Silica and biocompatibility

100 nm CHAp

nano-crystalline CHAp

Ca10 (PO4)6 (OH)2

Mg2+, Zn2+, Na+, K+ …

2- 2- SO4 , CO3 …

2- - - CO3 , F , Cl …

bone Ca10 (PO4)6 (OH)2 SiO 4- 4 Ca [(PO ) (CO ) ] [(OH) (CO ) ] B A 10-x/2 4 6-x 3 x 2-2y 3 y 2- carbonated hydroxyapatite x  0 CO3 18 The role of silica towards biocompatibility

3ml/min, room temperature

Ageing under stirring, 15h

Washing

0.297~0.217M 0.500M Ca(OH)2 H PO + Drying, 80C 3 4 0~80mM 100ml Si(CH3COO)4 pH10.5 100ml

silicate substituted HAp: a synthetic approach (4.8 wt. %)

E. Carlisle, Science 1970 G. Gasquères S. Hayakawa

19 Structural characterization

O1H edited 29Si MAS NMR!

20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 (ppm)

G = 125000

29Si MAS NMR Q0

Q3,Q4!?

29 4- SiO4

0 -20 -40 -60 -80 -100 -120 -140 -160 -180 (ppm) 20 SiO2 applications

«quartz clock»: piezoelectricity

W. Morrison 1929! silica wire birefringency

T ~ 1000°C tensorial properties 21 Glass

22 Glass structure

crystalline phase

glass colored glass

Cyclotella meneghiniana 23 Devitrification of glasses

microcrystals in glass

devitrified glass (by heating) 24 Fibers

optical fibers

cladding glass core glass

furnace

bundle of fiberglass exchange zone

cladding core fiber cladding

acceptance core cone

25 Sol-Gel chemistry

26 Silicic acid

0 OH 100% Si 80 HO OH Si(OH)4 OH SiO(OH) 3- 60 a weak acid SiO 2(OH)22- 40

silica is soluble at 20 precipitation of high pH: silicates silica 6 8 10 12 pH speciation H+ Na2O.SiO2

water 27 Inorganic polymerization

3- SiO3(OH) - SiO(OH)3 Si(OH)4 2- SiO2(OH)2 silica

drying molecules oligomers colloids powder nm 10 nm mm

colloidal silica particles

28 Stabilization of colloids

+ stabilisation against aggregation by surface charges + +

+ + + + + H + + + +

+ + + + + electrostatic repulsion + +

+ +

stabilisation by steric hindrance

grafted polymers

29 Precipited silica

■ industrial product: charge, chromatography,...

■ amazing chemistry!

silicates

CuSO4

FeCl 3 Ni(NO3)2

metal salts

30 Silicon alcoxides

molecular precursor water OR hydrolysis Si-OH bonds Si RO OR RO alcoxide

R = CH3, C2H5, ...

PZC condensation Si-O-Si bonds

acid catalysis base catalysis 31 Sol-Gel chemistry

inorganic polymerization O monomer O M O O solution hydrolysis O O dimer O M O M O OR OR O O + ROH RO Si OR + H2O RO Si OH OR OR O O O O oligomer O M O M O M O M O OR OR OR O O O O OR sol RO Si OH + RO Si OR RO Si O Si OR O O O OR OR OR OR O M O M O M O + ROH colloids O O O gel OR OR OR OR O M O M O M O O O O RO Si OH + HO Si OR RO Si O Si OR OR OR OR OR O O O O O O + HOH O M O M O M O M O M O M O condensation O O O O O O O M O M O M O M O M O M O oxide O O O O O O O M O M O M O M O M O M O solid chemistry of materials O O O O O O O M O M O M O M O M O M O oxides O O O O O O

32 The role of catalysis

fibers

nanoparticles

33 Control of the shape

acid catalysis (pH < 3) – route A Gel route A

chain polymers pH < 3 microporous gels (pores < 20Å) Sol (1-2 nm) base catalysis (pH >3) – route B pH > 3

route B spherical particles (Stöber silica) Sol (10-100 nm) mesoporous gels (pores > 20Å)

34 Stöber silica

Stöber, 1968 monodispersed silica colloids

5-2000 nm

interaction between Stöber silica and rubber Stöber silica monolayer 35 Silsesquioxanes

[XSiO1.5]8

[ RSiO1.5 ]n

Polyhedral Oligomeric SilSesquioxanes

36 Other silsesquioxanes

[XSiO1.5]6

[XSiO1.5]10

Courtesy of F. Ribot [XSiO1.5]12 37 Incomplete POSS

(RSi)7O9(OH)3

i R = c-C5H9, c-C6H11, c-C7H13, Bu

(c-C6H11Si)8O11(OH)2

Courtesy of F. Ribot 38 Chemistry and silsesquioxanes

F. Mammeri, 2005

39 Modified silsesquioxanes

increasing complexity...

...obtained by hydrosilylation molecular modeling 40 Silsesquioxanes as NanoBuildingBlocks (NBB)

NBB approach Z= H, -SiMe2H

Pt/toluene/90°C

Z’ = vinyl, -SiMe2vinyl

R. Laine, 1998

HF dissolution 41 Starting from natural materials

Rice hull ash 80-98 wt % amorphous silica!

Rice hull ash + [R4N ]8 + - 8 R4N OH

42 Applications

43 Hybrid organic-inorganic materials

organic component (molecules, polymers, …) inorganic component (M-O-M, …)

intimate "mixture" (domain sizes from 1 to 100 nm)

hybrid organic-inorganic materials (nano-composites)

infinite range

chemist‘s imagination and hability

nanometric oxide particles in a polymer organic dyes in a glass

44 Organic dyes and laser materials

■ any organic dye can be embedded ■ more resistant than in solution ■ large pieces ■ materials can be polished (optical quality)

2  2N  nL nH nL nH nL nH nL nH  n H      1   n L   R   2N  50   n H      1   n   (SiO /AlOOH)16  L  (%) Transmission 2 9 (SiO2/ZrO2-PVP) Tmin = 1.5 % Tmin = 1.0 % ZrO2 + PVP (20%)  nH = 1.72 0 500 800 1100 1400 SiO2  nL = 1.22

©CEA - France 46 Electrooptical switching encapsulation of liquid crystal microdroplets in a thin film

neff ≠ nm  Opaque (OFF state) Unpolarized light

Scattered light

Glass plate Transparent electrode (ITO) LC doplet - neff Silica gel-glass - nm n = n  Transparent (ON state) no o m

partially crosslinked art conservation: organic polymers vs inorganic coatings... fluoropolymer

desirable properties Au foil

■ thermal expansion match with the glass

■ low diffusion coefficients for SO2 and H2O gases

■ transparency

■ chemical bonding to the glass surface

■ longevity/UV resistance

■ possibility of inserting a gold foil within the coating

■ option to remove and re-apply the coating if necessary sol-gel coating

protective layer sacrificial layer

multilayer coatings non crosslinked fluoropolymer 48 Last Judgment Mosaic in Prague

before cleaning

after cleaning

after regilding Bescher et al. 2000 Getty Conservation St. Vitus cathedral Institute (14th century)

13m

10m

1 million pieces of tesserae in mortar www.getty.edu/conservation 49 Water, hydrophobicity and hydrophilicity

hydrophobic / hydrophilic silanes and surface modification descriptors of surfaces

 ( ’) a hydrophobic surface tends not to adsorb water R Si OR 3 or be wetted by water a hydrophilic surface tends to adsorb water or be CSi bond! wetted by water

organic substitution: - properties alkoxy groups: - reactivity - hydrolysis / condensation - surface modification 50 Water: an «universal» solvant

a dipolar molecule hydrogen bond ~ 20 kJ.mol-1

liquid water: the strong influence of hydrogen bond molecules of water in ice interactions

51 Wettability and contact angle

a simple quantitative method

 < 30°: hydrophilic surface

 < 10°: superhydrophilic

 > 90°: hydrophobic

 > 150°: superhydrophobic

ordinary: «typical wetting»

hydrophobic: «poor wetting» hydrophilic: «good wetting» 52 Surface modification: possible schematic views

hydrolytic deposition anhydrous deposition

H2O: added, on the surface, atmosphere...

vapor phase deposition

monolayers or 50°-120°C multilayers 4-12 hours 53 Surface modification: selection of silanes

 concentration of surface hydroxyl groups

 type of surface hydroxyl groups

 hydrolytic stability of the bond formed

 dimensions of the substrate

some solutions: monoalkoxysilanes, dipodal silanes... 54 Hypothetical trimethylsilylated surfaces

complete coverage

incomplete hydroxyl reaction

few bonding opportunities

pyrogenic silica: 5-7 OH/nm2 (less than 50% are reacted) 55 Lotus effect

Nelumbo nucifera

wax crystals

SEM picture of Lotus leaf 56 Self-cleaning surface

water droplet dust

R. Moret (in Nanomonde, CNRS ed)

Tropaelum majus (capucine) Lotus leaf surface

57 Mimicking nature

superhydrophobic coating

structured surfaces (Bico et al. 1999) water coated with hydrophobic silica powder

inverting the idea! Aussillous et al. 2001 glass

58 Patterning

PDMS PDMS 1) sol-gel precursor glass substrate

pressure 825-1250 Pa (24h) 2) glass substrate polydimethylsiloxane

heat treatment 3) glass substrate 110°C (1h) Courtesy of A. Pauletti

59 Characterization of modified silica nanoparticles: a spectroscopic challenge

? 60 Morphology

agregation

silica nanoparticles ( ~ 15 - 500 nm) 61 Grafting on silica nanoparticles: 29Si ?

S iO SiO22

29Si CP MAS F. Mammeri, MRS Proc. 847 (2005)

solution state NMR

chemical S. de Monredon, Paris 6 model shifts: 29Si Coll.: Rhodia company compounds 62 Hybrid organic/silica materials

intermolecular interactions organic fragment

non linear optic organization photochromism structuration catalysis periodicity ...

Dr. M. Wong Chi Man, CNRS, Montpellier 63 Self-organized hybrid silica

self-association

hydrolysis/condensation principal organic fragment

urea function chiral fragment flexible chain rigid

Dr. M. Wong Chi Man, CNRS, Montpellier 64 H-bond networks

H-N C=O H-N

Dr. M. Wong Chi Man, CNRS, Montpellier 65 Influence of the precursor on morphology

■ basic conditions

pure enantiomer (chiral fragment) racemic mixture

hollow tubes spheres

Dr. M. Wong Chi Man, CNRS, Montpellier 66 Towards bio-inspired materials...

intermolecular interactions

hydrolysis

hetero self-association homo self-association

Dr. M. Wong Chi Man, CNRS, Montpellier 67 Other associations

barbituric acid melanine

68 Ureidopyrimidinone derivatives: 1H spectroscopy

O Bo

M e N 400 N H N H 15 KHz O N H

(EtO)3Si

C R-Si(OEt)3 33 KHz ! D O O H N ? H O A, B, C, D 750 ! Me N Me N H N H N N B B N H N H A H N H N Me O O O O H H N H ppm Me N H R R C 20 10 0 -10 N O (EtO) Si 3 69 N AADD-DDAA H N R H O H O H O R Me N N Me N H N H H N H N N H N H N Me R O R O H O

DADA-ADAD R = Si(OEt)3

Réf: Angew .Chem. Int. E.d 2001, 40, 2382-2426 JACS 1998, 120, 6761-6769 1H DQ spectroscopy (Double Quantum)

excitation reconversion

1 t1 3 H DHH  1/r t 2 1H 1H tR/2 tR/2 tR/2 tR/2 r I=1/2 I=1/2 n n 2Q BAck to BAck 2Q hamiltonian! <++  -->

selectivity 2 1 1 2

2 1 2

1 1-1 1H

2 

1 1 + 2-1 1-2  dipolar links 1 22 H 2-2 2Q dim. 2Q ! 1H 1Q dim.

70 diso.: ultra fast MAS, high B0 field! R O O H O Me N Me N H N H 1 Ureidopyrimidinone derivatives: H DQN spectroscopy N N H N FileH : C:\Documents and Settings\bonhomme.LCMC\Bureau\WCMUPY3\WCMUPY3\020001.rr H N H N Me O O -Si(OCH2-CH3)3 O H H O Me N H R R N O N AADD-DDAA H N R H O H O H O R Me N N Me N H N H C R-Si(OEt)3 D H N H N N O O H N H H N H N Me O Me N Me N H N H R O N N B N R O H O H N H A H N H N Me O O O B H B----C H N H O DADA-ADAD Me N H R R = R C Si(OEt)3

N O (EtO)3Si B----B N AADD-DDAA 10 0 (ppm) H N R O H H HA HB HC HD 71 Réf: AngOew H.ChemO. Int. ER.d 2001, 40, 2382-2426 Me N JACS 1998, 120, 6761-6769 N Me N H N H H N H N N H N H N Me R O R O H O

DADA-ADAD R = Si(OEt)3

Réf: Angew .Chem. Int. E.d 2001, 40, 2382-2426 JACS 1998, 120, 6761-6769 Ureidopyrimidinone derived materials

-5 File : C:\Documents and Settings\bonhomme.LCMC\Bureau\WCMAGM152B\Bruno\Collaborations\CMC ACI 2004\WCMAGM152B\120001.rr hydrolysis / condensation 1H BABA

0 0 H+ 17.6 T 5

5251 MAS 33 kHz

Hd-He 10 1 Hd-Hd H HA,HB,HC,HD Hc-Hpropyl + 10502 H 15 H -H a e 17.6 T H -H a d MAS 33 kHz 20 15753 Hb-Hc Hb-Hb 25 O

21004 C R-Si O D N O 10 O 0 (ppm) O H H O 13 Me C N Me N H N H N N B N C=O H N H A H N H N Me O O O B H H N H O Me N H R O R C N O O Si N (ppm) 200 100 0 O AADD-DDAA 72 H N R H O H O H O R Me N N Me N H N H H N H N N H N H N Me R O R O H O

DADA-ADAD R = Si(OEt)3

Réf: Angew .Chem. Int. E.d 2001, 40, 2382-2426 JACS 1998, 120, 6761-6769 Silica aerogel – supercritical drying an old idea: S. Kistler 1931! silica gel supercritical drying

99.8 % air! r = 3 mg/cm3!

P. Tsou - NASA

73 Aerogels: remarkable properties

Stardust

heat insulator impact

Stardust

mechanical properties Wild-2 comet 74 Silica gel

US patent: W.A. Patrick (1919)

■ S = 800 m2/g

■ desiccant

■ can be regenerated

CoCl (anhydrous) CoCl (hydrated) 2 2 75 Silicon carbide: outstanding properties!

SiC a unique natural example: meteor impact in Canyon Diablo!

Arizona DT electric furnace C SiC SiO2

◊ abrasive (carborundum) ◊ hardness (Mohs: 9.6!) ◊ refractory ◊ thermal schock resistance

76 The role of precursors

traditional ceramics

50 mm

polymeric precursors

nanostructured SiCO phase

G. D. Soraru, Trento (Italy) 77 Oxidation and chemical resistance

T = 1350 °C, 100h HF

SiO2

SiCO 10 mm

SiO2 SiCO

SiCO + O2 SiO2 + CO

Modena, J. Am. Ceram. Soc. Soraru, J. Am. Ceram. Soc., 2002

78 Fibers

CH3 CH3 CH3 SiOC fiber obtained at 1000 °C H3C Si O Si O n Si CH3

CH3 H CH3

 >1.5GPa

base solution (Portland cement)



G.D. Sorarù, S. Dirè. A. Berlinghieri, “Procedimento per la SiO SiCO produzione di fibre di ossicarburo di silicio”, Domanda 2 Italiana di Brevetto per Invenzione Industriale, N. TO2002A000887, 2002.

79 Biogenic silica

80 Radiolaria

E. Haekel (1834-1919)

Kunstformen der Natur (1904)

Lamprocyclas maritalis

cell Rhizoplegma boreale protozoa Lophospyris pentagona siliceous skeleton

radial symmetry 81 Shapes

(V,E,F) (4,6,4) (12,30,20)

Platon 427-348 av. JC tetraedron (20,30,12) Callimitra agnesae icosaedron (8,12,6)

(6,12,8)

dodecaedron cube

octaedron Lithocubus geometricus

Prismatium tripodium 82 Shapes and soap bubbles

Callimitra agnesae

Lithocubus geometricus

Prismatium tripodium 83 Silicon oxycarbide

R. Blum DEA Paris 6

SiO/SiC

(MeO)3Si-CH2CH2-Si(OMe)3 CTAC

~ 1mm (10-6 m) 84 Towards mathematics!

J. Gielis superformula y Am. J. Botany, 90, 2003, 333

Y r  x X

parametrization

r = r() (1/a cos(m/4)n2 + 1/b sin(m/4)n3)-1/n1

85 Meaning of the parameters

r =

(1/a cos(m/4)n2 + 1/b sin(m/4)n3)-1/n1

«size» symmetry shape

Nuphar luteum Scrophularia nodosa Equisetum raspberry

86 Rose sepals

m = 5/2 m = 5/3

m = 5 [0,2p]

[0,2p]

[0,4p] [0,2p]

0,5 0,5 0,5 n1 n2 n3 [0,4p]

[0,6p] 87 Extension to 3D images

Genicap Supergraphx @ 3D Shape Explorer P. Bourke, Australia 88 Back to sea organisms: diatoms

Surirella fastuosa Actinotychus senarius m = 0

m = 2

Triceratium favum Biddulphia antediluviana

m = 3 m = 4 89 Diatoms

...micro-organisms living in the sea plankton... silica glass from aqueous solution!

amorphous silica

unicellular algae in a silica cage

strong (protection)

transparent (photosynthesis)

porous (metabolism) J. Livage, T. Coradin 90 Variety of shapes

25 % of whole CO2 via photosynthesis!

≈ 50.000 species 91 Hierarchical porous materials starting from mm...

...to nm range! 92 Diatoms as porous materials

filtration absorption catalysis ...

Solid phase extraction purification of DNA US Patent Issued on April 11, 1995 Claims

What is claimed is:

1. A method for purifying DNA from solution in the absence of chaotropes which comprises:

a) adding to the solution (i) a hydrophilic surface selected from the group consisting of celite diatoms, silica polymers, magnesium silicate, silicon nitrogen compounds, aluminum silicates, silica dioxide, glass fiber and nitrocellulose, and (ii) a water soluble organic solvent selected from the group consisting of 80-100% isopropanol, 80-100% propanol, 95-100% ethanol, 100% acetonitrile, and mixtures consisting essentially of 20-80% of each of at least two alcohols selected from the group consisting of isopropanol, propanol and ethanol; 93 Silica in plants

bamboo

hardness of bamboo: combination of lignin fibers and silica (up to 5%!) leaf (G > 1000) 94 Characterization of silica in plants

in: Plant Physiol. 1958

silica particles (corn leaf)

powder XRD of silica from lantana (leaf, stem)

95 Experimental – enjoy!....

spinel structure AB2O4 with A: 2+ and B: 3+

normal spinels: A2+ (Td), B3+ (Oh) inverse spinels: A2+ and ½ B3+ (Oh), ½ B3+ (Td)

Magnetite Fe3O4 2+ 3+ (Fe Fe 2O4)

ferrofluid in the presence of a magnet