1. MESOCHEMISTRY SYNTHESIS IN “INTERMEDIATE” DIMENSIONS
CHEM 1270H: TOPICS IN INORGANIC CHEMISTRY
MESOCHEMISTRY SYNTHESIS IN “INTERMEDIATE” DIMENSIONS
Geoffrey A. Ozin
Materials Chemistry Research Group
University of Toronto
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3. MESOCHEMISTRY SYNTHESIS IN “INTERMEDIATE” DIMENSIONS
Purpose of the four lectures
Introduce key physicochemical design principles that underpin the template directed synthesis of inorganic mesoporous materials
Focus on synthetic control of structure, composition and form
Appreciate how the properties of materials fashioned at this intermediate length scale can be orchestrated to create a purposeful function directed to a specific field of use.

4. Angew Chem 2006, 45, 3216

5. ZEOLITES CRYSTALLINE MICROPOROUS ALUMINOSILICATES WITH PORES AND CHANNELS IN SIZE RANGE 0.3-1NM

6. ESCAPE FROM THE 1NM ZEOLITE PRISON
ISI Citations 6386

7. ESCAPE FROM 10 Å PRISON
Discovery by Mobil researchers that an assembly of surfactant molecules could function as a supramolecular template for organizing and polymerizing silicates
Produced the first fully characterized examples of periodic hexagonal and cubic forms of mesoporous silica with pore diameters 2-10 nm
Integration of surfactant and sol-gel chemistry

8. SOL-GEL CHEMISTRY
Air drying
SC CO2 drying

9. SOL-GEL CHEMISTRY
Air drying

10. SOL-GEL CHEMISTRY Base catalyzed hydrolytic poly-condensation of silicon alkoxides to silica

11. SOL-GEL CHEMISTRY Acid catalyzed hydrolytic poly-condensation of silicon alkoxides to silica
HYDROLYSIS
(RO)3SiOR + H3O+  (RO)3SiORH+ + H2O
2H2O + (RO)3SiORH+ (RO)3SiOH + ROH + H3O+   
CONDENSATION
(HO)3SiOH + H3O+  (HO)3SiOH2+ + H2O
(HO)3SiOH + (HO)3SiOH2+  (HO)3SiOSi(OH)3 + H3O+   

12. SOL-GEL CHEMISTRY

13. Lyotropics
Kraft T

14. CO-ASSEMBLY SURFACTANT AND SOL-GEL CHEMISTRY

16. MILESTONES IN MESOPOROUS MATERIALS
Escape from the 1 nm prison (surfactant templated synthesis)
Diagnostics (structure, property)
Structure control (H, C, L, WH)
Template removal (calcination, ion exchange, solvent extraction, photocalcination, ozonolysis, microwave, lizard fragmentation)
Pore size control (surfactant, block copolymer, swelling additive)
Templating mechanism (micelle, liquid crystal)
Smart mesostructure (pore size expansion, metamorphic channels)
Free-standing and supported film (mesoepitaxy, pore orientation)
Topological defects (nucleation, growth, origin of curved pores and form)
Morphogenesis of curved shapes (fiber, discoid, gyroid, spiral, sphere)

17. MILESTONES IN MESOPOROUS MATERIALS
Nanomeso (nanoscale particles, nanocrystalline texture)
Biomimetics (biomineralization connection, hierarchy (nm-micron length scales), complexity, organic-inorganic nanocomposites or hybrids)
Panoscopic materials (global self-assembly over “all” scales, surfactants, block copolymers, opals)
Patterning (microcontact printing, micromolding in capillaries, microtransfer printing, ink jet printing, photolithography)
Smart guests (SC, M, OM, C, P)
Smart channels (terminal and bridging organofunctionality)
Beyond silica (metals, oxides, sulfides, phosphates, coordination, polymers)
Mesoreplication (carbons, metal oxides)
Function and utility (fuel cell, solar cell, battery, laser, low-k, controlled chemical and drug release, chemical/biosensor, electrochromic display, 1D Bragg photonic crystals, low refractive index optical cladding )

20. pH, pH, pH EFFECT ON SELF-ASSEMBLY MECHANISM
Temperature
Ageing conditions
Precursor
Surfactant pH
Catalyst
Concentration
Template removal

21. HYDROLYSIS, CONDENSATION, SELF-ASSEMBLY

22. HEXAGONAL MESOPOROUS SILICA
ESCAPE FROM 10 Å PRISON
100
110
200
210
HEXAGONAL MESOPOROUS SILICA

23. IUPAC CONVENTION FOR PORE SIZES
Small angle X-ray diffraction
Nitrogen gas adsorption isotherms
hexagonal
Mesoporous nm
Macroporous > 50 nm
cubic
Microporous < 2 nm
lamellar
IUPAC CONVENTION FOR PORE SIZES

24. CUBIC BICONTINUOUS MESOPOROUS SILICA
Equipotential minimal energy surface
TEM image cubic mesoporous structure
Mesocrystalline glass – crystalline mesoporosity - periodic arrangement of mesopores – glassy walls - long range order at mesoscale – short range order at microscale
Cubooctahedral morphology

25. WHAT CAN WE DO WITH PMS MATERIALS
WHAT CAN WE DO WITH PMS MATERIALS? HOST-GUEST INCLUSION WITH LARGE GUESTS !!!

26. ORGANICALLY FUNCTIONALIZED PMS - GRAFTING

27. CLEVER USE OF GRAFTING CONTROLLED RELEASE OF ACTIVE COMPOUNDS

28. NANO-PMS SMART DRUG DELIVERY AFM 2007

29. ORGANICALLY FUNCTIONALIZED PMS - COCONDENSATION

30. PHOTOCHEMICAL SWITCH PORE SIZE CONTROL
Synthesis of films bearing photosensitive azobenzene units: 4-(3-triethoxysilyl-propylureido) azobenzene by the coupling of triethoxysilylpropylisocyanate with 4-phenylazoaniline used as organosilane precursor in co-condensation reaction

31. HEAVY METAL SPONGE
Periodic mesoporous silica with channel walls functionalized with terminally bound alkanethiol groups that chelate and sequester toxic heavy metals.

33. PERIODIC MESOPOROUSN ORGANOSILICAS PMOs

35. ZOO OF PMO PRECURSORS

36. Acc. Chem. Res. 2005, 38,

37. MATERIALS CHEMISTRY SOLUTION TO THE LOW k CHALLENGE
Periodic mesoporous organosilicates PMOs with organic cross-links!!!
Hatton, B.D., Landskron, K., Hunks, W.J., Bennett, M.R., Shukaris, D., Perovic, D.D., Ozin, G.A., New Materials Chemistry Approaches for Low Dielectric Constant Materials as Interlayer Dielectrics, Materials Today 2006, 9, 22.

38. METAMORPHIC CHANNEL WALLS – PMO BRIDGE TERMINAL EXCHANGE

39. PMO WITH ORDERED BRIDGING AROMATIC GROUPS IN THE CHANNEL WALLS

40. MOLECULAR MODEL OF THE ORDERING OF BRIDGING BENZENE GROUPS IN THE CHANNEL WALL OF BENZENE PMO

41. MOLECULAR MODEL OF THE ORDERING OF BRIDGING THIOPHENE GROUPS IN THE CHANNEL WALL OF THIOPHENE PMO

42. BIFUNCTIONAL PMOs

43. The Idea – PMO to MIPMO
IMPRINT

44. the idea
IMPRINT
imprint
molecule
imprint
removal

45. collaboration Jean-Christophe Leroux (CRC in Drug Delivery)
Nature Nanotechnology. 2007, 2,
liposomes, nanoemulsions, nanoparticles, macromolecules 45

46. MIPMOs
Schematic of the synthesis of molecular imprinted periodic mesoporous organosilica MIPMO materials

47. calcium channel blockers
Drug-PMOs
commercially available drugs
↳silsesquioxane PMO precursors
↳assemble MIPMO structures
↳remove the drug imprints
↳detoxification
Diltiazem
calcium channel blockers
Verapamil

48. Drug Silsesquioxanes

49. MESOPOROUS MATERIALS GRAND CHALLENGES – UTILITY
Large (bio)molecule catalysis
Polymerization nanoreactor
Membrane separation
Chromatography stationary phase
Fuel cell anode
Lithium battery electrolytes
Electrochromic display
Solar cell photo-cathode
(Bio)chemical sensor
Drug storage and release vehicle
Heavy metal sponge
Low dielectric constant film
Low refractive index optical cladding
Lithographic masks
Nanofluidic ion channels
Nanocomposites