Transcript Lecture 7 Hybrid POSS Materials

Lecture 7 Hybrid POSS Materials
Class 1C Organic phase is made in
situ in the inorganic phase.
and D: Small organic phase
dispersed in continuous inorganic
phase
Just a reminder:
Class I
Class II
No chemical bond between components
Chemical bonds between components
only weak interactions
strong interactions
(van der Waals, hydrogen, electrostatic)
(covalent bonds)
O
O
O
Si
O 2N
NH 2
NO
2
O
Si
O
O
Si
O
Si
O
O
HO
O
Entrapping
O
O
O
Si
O 2N
O
NH
O
Si
O
NO
O
O
O
O
Si
O
O
Si
2
O
O
Grafting
J. Livage
Making Hybrid Materials: Class 1C
(Polymerizing in pores)
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Non-porous composite material
•Porous metal oxide
•Liquid monomer (no solvent)
•UV, heat, radiation
Making Hybrid Materials: Class 1C
(Polymerizing in pores)
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1) Monolithic inorganic Polymer nanocomposite from
completely filling pores
2) Reinforced xerogel or aerogel by coating aggregated
particles with polymer
3) Polymerizing intercalated monomers in clay
4) Polymer surrounding colloid crystal of inorganic
First example: Monolithic inorganic Polymer
nanocomposite from completely filling pores
S ke le ta l
stru c tu re
P o re s
P o re s fille d w ith m o n o m e r
In filtra te
w ith
o rg a n ic
m onom er
P o re s fille d w ith s o lid p o ly m e r
P o ly m e riz e
liq u id in to
s o lid
& c a ta ly s t
• Infiltration & polymerization of monomer in pores of gel
• Provides a percolating filler phase based on the original gel skeleton
Acc. Chem. Res., 2007, 40 (9), 810–818
First example: Monolithic inorganic
Polymer nanocomposite from completely
filling pores
Pure silica
Pure
PMMA
Transparent, tough, tailorable refractive index, abrasion resistant
Pope, E. J.; Asami, M.; Mackenzie, J. D. Transparent silica gel–PMMA composites
J. Mater. Res. 1989 4 4 1018
Reinforced xerogel or aerogel by coating
aggregated particles with polymer
Porous materials, like aerogels, are super thermal insulation, but very weak
P o lym e rize
m onom er
to glu e
pa rticles
to g e the r
O
NC
O
cy an o acrylate: "S up erglue"
D ry G el: X ero gel or aerogel
P olym er reinforced xero gel o r aerogel
Monomers, such as superglue, can be polymerized directly on surface by
chemical vapor deposition
Boday, D. J.; Stover, . J.; Muriithi, B.; Keller, M. W.; Wertz, J. T.; DeFriend Obrey, K. A.; Loy, D. A.
ACS Applied Materials & Interfaces 2009, 1(7), 1364.
Reinforced xerogel or aerogel by coating
aggregated particles with polymer
monomers can be polymerized in solution if they will precipitate onto the
particles surfaces.
P o ly m e riz e
m o n o m e r in
s o lu tio n & p h a s e
s e p a ra te p o ly m e r
a s s o lid o n to
p a rtic le s
W et ino rg an ic gel
organic p oly m er reinfo rced inorganic gel
Epoxies, urethanes, some vinyl polymers
Acc. Chem. Res., 2007, 40 (9), pp 874–884
S u p e rc ritica lly
d ry to re m o ve
s o lv e n t w ith o u t
s h rin k in g
organic p olym er rein fo rced
in organic aero gel
Polymer-Clay Nanocomposites from
intercalation & polymerization of monomers
O
NH
c a p ro la c ta m
M o n tm o rillo n ite
a s c a ta ly st
O
H 2N
O
N
H
2 5 0 °C
OH
N ylo n -6
6 -a m in o h e x a n o ic a c id
1) First heat 100 g montmorillonite (MMT) with 51.6 g of aminolauric acid and 24 mL
conc. HCl in 10 Liters of water for 10 min.
2) Filter, was 3X with 10 L hot water, then freeze dry, then dry under vacuum at 100
°C to afford ion exchanged, intercalated MMT
3) Mix 29.7 g intercalated MMT, 509 g caprolactam, and 66 g 6-aminocaproic acid
were mixed in mortar in pestle.
4) The mixture was polymerized in3000 mL round bottom flask with mech. Stirrer and
under nitrogen for 30 min at 100 °C then for 6 h at 250 °C.
5) The products were crushed in mortar & pestle, then washed with water and dried at
89 °C.
A. Usuki, Y. Kojima, M. Kawasumi, A. Okada, Y. Fukushima,T. Kurauchi, O. Kamigaito, "Synthesis of
nylon 6-clay hybrid," J. Mater. Res. 1993, 8, 1179
n
Polymer colloidal crystal nanocomposites
1) Prepare a colloidal crystal (opal) from silica particles
2) Add monomer & catalyst to fill pores
3) Polymerize to form72% by volume silica filled organic polymer
4) Dissolve silica away with HF if inverse opal is desired
Microporous and Mesoporous Materials 2001,44-45, 227 - 239
Class 1D: Small organic
phase dispersed in
continuous inorganic
phase
Making Hybrid Materials: Class 1D
(encapsulation of small organics)
HO
HO
OH
O O
O
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c a ta ly s t
O
HO
O O
H 2O
HO
O
• Polymerize metal oxide around organic
• pores must be small or leakage will occur
•Solid state dye lasers, filters, colored glass
•sunscreens
•Biopolymers
•Medicines
•Living cells
•Imprinting (artificial enzymes)
O
© AsahiKirin
O
Class 1D: the organic dye is trapped
within the silica network
sol-gel precursor
Si(OR)4
organic molecule
Solution
(common solvent)
H2
O
ROH
Si(OR)4
Si(OR)4
ROH
Hydrolysis-condensation
Si(OR)4
Si(OR)4
ROH
organic molecule
trapped in the
silica matrix
Simple method for encapsulating dyes.
Easily recyclable colored
bottles
Si(OCH3)4 + Ti(OC3H7)4
CH2=CH-Si(OC2H5)3
methacrylate-Si(OC2H5)3
organic dyes
UV and D curing
• Organic dyes
 large choice of colors (marketing !)
 pigments can be burned off before recycling
© Asahi-Kirin
• Hybrid coatings
 improved mechanical properties of bottl
J. Livage
Organic dyes in a silica matrix
Matech
fluorescence - laser - NLO - photochromism
J. Livage
Optical limiters
nonlinear hybrid C60-silica coated lenses
Preventing UV-light damage of light sensitive
materials using a highly protective UV-absorbing
Hybrid (Class 1D) coating
Absorption spectrum of the UV protecting film (1 µm) with and without
the UV-absorber molecule (34 wt%).
Chem. Soc. Rev., 2007, 36, 1270-1281
Dyes are protected against
photodegradation by Class 1D matrix
Visible absorption spectra of Photosystem I entrapped in sol–gel at intervals during
the aging process compared with the solution spectrum of the native preparation. The
spectrum of a control gel without PSI that was aged for 29 days is also shown
H. O'Neill and E. Greenbaum, Chem. Mater.,
2005, 17, 2654
Fluorescent core–shell silica nanoparticles incorporating organic dyes with
different spectral characteristics, covering the entire UV-vis absorption and
emission wavelengths. (Reproduced from ref. 31, with permission. Copyright
2005 American Chemical Society.)
H. Ow, D. R. Larson, M. Srivastava, B. A. Baird,
W. W. Webb and U. Wiesner, Nano Lett., 2005,
5, 113
Sol-gel encapsulation of drugs in silica
particles using microemulsions
Water in oil emulsions
Enzymes in sol-gel
Requires mild sol-gel (pH 7)
Enzymes remain active longer than when in water
Sensors and catalysts
Science 1992, 255, 1113– 1115
Chem. Soc. Rev., 2007, 36, 932-940
Cyctochrome C encapsulated in dry aerogels
Generally thought that water is needed for enzyme activity
Aerogels made with cytochrome C have remained active
NO sensors
Amanda S. Harper-Leatherman Langmuir, Article ASAP 2012
Bio encapsulation: Photosynthesis system
Chem. Mater., 2005, 17 (10), pp 2654–2661
Enclapsulation of liposomes in silica gel
Langmuir, 1997, 13 (19), pp 5049–5053
Encapsulating living cells in silica
Bacteria encapsulated within a silica matrix aged for (a) 1 month
without glycerol and (b) 1 day with a layer of glycerol.
Imprinting to make synthetic enzymes
in hybrid materials
Imprinting dopamine
analogs into
silsesquioxane
modified silicas for
sensors
Chem. Mater., 2003, 15 (19), pp 3607–3613
Imprinting DDT into
silsesquioxane modified
silicas for sensors
Imprinting Caffeine
into silica modified
with silsesquioxane
with non-bonding
interactions
C. Lin, A. Joseph, C.K. Chang, Y.C. Wang, Y.D. Lee Anal. Chim. Acta, 481 (2003), p. 175
Imprinting dopamine analogs
into silsesquioxane modified
silicas for sensors
C.W. Hsu, M.C. Yang, J. Non-Cryst Solid, 354 (2008), p. 4037
Imprinting that generates on optical signal
when site recognizes molecule
Acc. Chem. Res., 2007, 40 (9), pp 756–
767
Encapsulated UV-Filters
Organics undergo photodegradation
free radicals
encapsulation of organic filters
in hollow silica spheres
Merck - Germany
1m
safe and inert UV-filters
that do not penetrate the skin
J. Livage
Merck
aqueous suspension containing ≈ 40% nanoparticles
J. Livage