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
Dec 30, 2015
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
Class I
No chemical bond between
components
only weak interactions
(van der Waals, hydrogen,
electrostatic)
Class IIChemical bonds between
componentsstrong interactions(covalent bonds)
Entrapping GraftingJ. Livage
Just a reminder:
Making Hybrid Materials: Class 1C(Polymerizing in pores)
•Porous metal oxide•Liquid monomer (no solvent) •UV, heat, radiation
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catalyst
Non-porous composite material
Making Hybrid Materials: Class 1C(Polymerizing in pores)
1) Monolithic inorganic Polymer nanocomposite from completely filling pores2) Reinforced xerogel or aerogel by coating aggregated particles with polymer3) Polymerizing intercalated monomers in clay 4) Polymer surrounding colloid crystal of inorganic
First example: Monolithic inorganic Polymer nanocomposite from completely filling pores
• 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
Pope, E. J.; Asami, M.; Mackenzie, J. D. Transparent silica gel–PMMA composites J. Mater. Res. 1989 4 4 1018
Transparent, tough, tailorable refractive index, abrasion resistant
Reinforced xerogel or aerogel by coating aggregated particles with polymer
Porous materials, like aerogels, are super thermal insulation, but very weak
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
Epoxies, urethanes, some vinyl polymers
monomers can be polymerized in solution if they will precipitate onto the particles surfaces.
Acc. Chem. Res., 2007, 40 (9), pp 874–884
Polymer-Clay Nanocomposites from intercalation & polymerization of
monomers
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
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 MMT3) 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.
Polymer colloidal crystal nanocomposites
Microporous and Mesoporous Materials 2001,44-45, 227 - 239
1) Prepare a colloidal crystal (opal) from silica particles2) Add monomer & catalyst to fill pores3) Polymerize to form72% by volume silica filled organic polymer4) Dissolve silica away with HF if inverse opal is desired
Making Hybrid Materials: Class 1D(encapsulation of small organics)
• 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)
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
Preventing UV-light damage of light sensitive materials using a highly protective UV-absorbing Hybrid (Class 1D) coating
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
Dyes are protected against photodegradation by Class 1D matrix
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
Chem. Soc. Rev., 2007, 36, 932-940
Enzymes in sol-gel
Requires mild sol-gel (pH 7) Enzymes remain active longer than when in waterSensors and catalysts Science 1992, 255, 1113– 1115
Cyctochrome C encapsulated in dry aerogels
Generally thought that water is needed for enzyme activityAerogels made with cytochrome C have remained activeNO sensors
Amanda S. Harper-Leatherman Langmuir, Article ASAP 2012
Bacteria encapsulated within a silica matrix aged for (a) 1 month without glycerol and (b) 1 day with a layer of glycerol.
Encapsulating living cells in silica
Chem. Mater., 2003, 15 (19), pp 3607–3613
Imprinting dopamine analogs into silsesquioxane modified silicas for sensors
C. Lin, A. Joseph, C.K. Chang, Y.C. Wang, Y.D. Lee Anal. Chim. Acta, 481 (2003), p. 175
Imprinting Caffeine into silica modified with silsesquioxane with non-bonding interactions
C.W. Hsu, M.C. Yang, J. Non-Cryst Solid, 354 (2008), p. 4037
Imprinting dopamine analogs into silsesquioxane modified silicas for sensors
Acc. Chem. Res., 2007, 40 (9), pp 756–767
Imprinting that generates on optical signal when site recognizes molecule