1. CHIMIE DOUCE: SOFT CHEMISTRY
Synthesis of new metastable phases
Materials not usually accessible by other methods
Synthesis strategy often involves precursor method
Often a close relation structurally between precursor phase and product
Topotactic transformations

2. CHIMIE DOUCE: SOFT CHEMISTRY
Tournaux synthesis of a new form of TiO2
Beyond Rutile, Anatase, Brookite and Glassy form!!!
KNO3 (ToC)  K2O (source)
K2O + 4TiO2 (rutile, 1000oC)  K2Ti4O9
K2Ti4O9 + HNO3 (RT)  H2Ti4O9.H2O
H2Ti4O9.H2O (500oC)  4TiO2 (new slab structure) + 2H2O

3. KIRKENDALL EFFECT IN TOURNAUX SYNTHESIS OF SLAB FORM OF TiO2
16K + - 4Ti TiO2  8K2Ti4O9
4Ti K+ + 9K2O  K2Ti4O9
Overall reaction stoichiometry
9K2O + 36TiO2  9K2Ti4O9
RHS/LHS = 8/1 Kirkendall Ratio

4. RUTILE CRYSTAL STRUCTUREz x y

5. SEEING THE 1-D CHANELS IN RUTILE

6. Different to rutile, anatase or brookite forms of TiO2
NEW METASTABLE POLYMORPH OF TiO2 BASED ON K2Ti4O9 SLAB STRUCTURE - (010) PROJECTION SHOWN 1
Topotactic loss of H2O from H2Ti4O9 to give “Ti4O8” (TiO2 slabs) plus H2O, where two bridging oxygens in slab are protonated (TiOHTiOTiOH) 1
1/2
1/2 x2 1
1/3 x2 1
1/3
1/3 x2
1/3
1/2
1/3 x2
1/3
K+ at y = 3/4
1/2
K+ at y = 1/4
Different to rutile, anatase or brookite forms of TiO2

7. CHIMIE DOUCE: SOFT CHEMISTRY
Figlarz synthesis of new WO3
WO3 (cubic form) + 2NaOH  Na2WO4 + H2O
Na2WO4 + HCl (aq)  gel
Gel (hydrothermal)  3WO3.H2O
3WO3.H2O (air, 420oC)  WO3 (hexagonal tunnel structural form of tungsten trioxide)
More open tunnel form than cubic ReO3 form of WO3

8. Slightly tilted cubic polymorph of WO3 with corner sharing Oh WO6 building blocks, only protons and smaller alkali cations can be injected into cubic shaped voids in structure to form bronzes like NaxWO3 and HxWO3
1-D hexagonal tunnel polymorph of WO3 with corner sharing Oh WO6 building blocks, can inject larger alkali and alkaline earth cations into structure to form bronzes like RbxWO3 and BaxWO3 as well as HxWO3 a 1D proton conductor having mobile protons diffusing from O site to site along channels

9. Structure of h-WO3 showing large 1-D tunnels
Apex sharing WO6 Oh building blocks
Hexagonal tunnels
Injection of larger M+ cations like K+ and Ba2+ than maximum of Li+ and H+ in c-WO3
Structure of h-WO3 showing large 1-D tunnels

10. Functional device, LED, laser, sensor, biolabel
Ligand capping arrested growth of nanocluster core
Growth and ligand capping of nanocluster core
High T solvent, ligand, protection, amphiphilic amines, carboxylic acids, phosphines, phosphine oxides, phosphonic acids
Inorganic precursor, oxides, sulphides, metals, nucleation of nanocluster seed

11. nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P
Arrested nucleation and growth synthetic method for making semiconductor nanoclusters in a high-boiling solvent. Adding a non-solvent causes the larger nanocrystals to precipitate first, allowing size-selective precipitation and nanocluster scaling laws to be defined
nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P

12. ARRESTED GROWTH OF MONODISPERSED NANOCLUSTERS
Hydrophobic sheath of alkane chains of surfactant make the nanoclusters soluble in non-polar solvents - crucial for achieving purification and size selective crystallization of the nanoclusters.
nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P
Tributylphosphine selenide in a syringe is rapidly injected into a 300C solution of dimethyl cadmium in trioctylphosphine oxide surfactant-ligand-solvent, known as TOPO.

13. SIZE SELECTIVE CRYSTALLIZATION OF LIGAND CAPPED NANOCLUSTERS
Gradually add non-solvent acetone to a toluene solution of capped nanoclusters
Causes larger crystals to precipitate then smaller and smaller crystals as the non-solvent concentration increases.
Smaller ones more soluble because of easier solvation of less dense packed alkanethiolate chains.

14. SIZE SELECTIVE CRYSTALLIZATION OF LIGAND CAPPED NANOCLUSTERS
When non-solvent added, nc-nc contacts become more favorable than nc-solvent interactions.
Larger diameter capped nanoclusters interact via the chains of the alkanethiolate capping ligands more strongly than the smaller ones due to the smaller curvature of their surface and the resulting greater interaction area.
As a result they are caused to flocculate that is aggregate and crystallize first.

15. SIZE SELECTIVE CRYSTALLIZATION OF LIGAND CAPPED NANOCLUSTERS
Process repeated to obtain next lower size nanoclusters and procedure repeated to obtain monodispersed alkanethiolate capped gold nanoclusters.
Further narrowing of nanocluster size distribution achieved by gel electrophoresis – an electric field driven size exclusion separation stationary phase.

16. BASICS OF NANOCLUSTER NUCLEATION, GROWTH, CRYSTALLIZATION AND CAPPING STABILIZATION
Addition
of reagent
Gb > Gs
supersaturation
nucleation
aggregation
capping and stabilization
nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P

17. CAPPED MONODISPERSED SEMICONDUCTOR NANOCLUSTERS
EgC = EgB + (h2/8R2)(1/me* + 1/mh*) - 1.8e2/R
Quantum localization term
Coulomb interaction between e-h
CAPPED MONODISPERSED SEMICONDUCTOR NANOCLUSTERS
nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P

20. SIZE DEPENDENT OPTICAL ABSORPTION SPECTRA OF CAPPED CDSE NANOCLUSTERS, SYNTHESIS AND CHARACTERIZATION OF NEARLY MONODISPERSE CdE (E = S, Se, Te) SEMICONDUCTOR NANOCRYSTALLITES, MURRAY CB, NORRIS DJ, BAWENDI MG, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 115 (19): SEP )

21. SIZE AND COMPOSITION DEPENDENCE OF THE OPTICAL EMISSION SPECTRA OF CAPPED InAs (RED), InP (GREEN) AND CdSe (BLUE), BRUCHEZ, M.JR; MORONNE, M.; GIN, P.; WEISS, S.; ALIVISATOS, A.P. SEMICONDUCTOR NANOCRYSTALS AS FLUORESCENT BIOLOGICAL LABELS, SCIENCE 1998, 281, 2013

22. PXRD, MALDI-MS, TEM CHARACTERIZATION OF CLUSTER CORE, CLUSTER SEPARATION LIGAND SHEATH,
Nanocluster Synthetic Control – size, shape, composition, surface chemical and physical properties, separation, amorphous, crystalline
Do it yourself quantum mechanics – synthetic design of optical, electrical, magnetic properties

23. nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P
ARRESTED GROWTH OF MONODISPERSED NANOCLUSTERS CRYSTALS, FILMS AND LITHOGRAPHIC PATTERNS
nMe2Cd + nnBu3PSe + mnOct3PO  (nOct3PO)m(CdSe)n + n/2C2H6 + nnBu3P

24. MONODISPERSED CAPPED CLUSTER SINGLE CRYSTALS
Rogach AFM 2002
methanol
2-propanol
toluene
MONODISPERSED CAPPED CLUSTER SINGLE CRYSTALS

25. TRI-LAYER SOLVENT DIFFUSION CRYSTALLIZATION OF CAPPED NANOCLUSTER SINGLE CRYSTALS. MeOH TOP LAYER, TOLUENE BOTTOM LAYER, 2-PROPANOL MIDDLE BUFFER LAYER - OMITTING THE BUFFER LAYER CREATED ILL-DEFINED CRYSTALS, A NEW APPROACH TO CRYSTALLIZATION OF CdSe NANOPARTICLES INTO ORDERED THREE-DIMENSIONAL SUPERLATTICES, TALAPIN DV, SHEVCHENKO EV, KORNOWSKI A, GAPONIK N, HAASE M, ROGACH AL, WELLER H, ADVANCED MATERIALS, 13 (24): 1868, 2001

26. GOLD ATOMIC DISCRETE STATES
GOLD CLUSTER DISCRETE MOLECULE STATES
GOLD QUANTUM DOT CARRIER SPATIAL AND QUANTUM CONFINEMENT
GOLD COLLOIDAL PARTICLE SURFACE PLASMON – 1850 MICHAEL FARADAY ROYAL INSTITUTION GB PIONEER OF NANO!!!
BULK GOLD PLASMON

27. SELF-ASSEMBLING AUROTHIOL CLUSTERS
Diagnostic cluster size dependent optical plasmon resonance originating from dipole oscillations of conduction electrons spatially confined in nanocluster – wavelength plasmon depends on size, type of capping ligand and nature of the environment of nanocluster – also size dependent electrical conductivity – hopping from cluster to cluster - useful in nanoelectronic devices and nanooptical sensors – Faraday would be pleased!!!
HAuCl4(aq) + Oct4NBr (Et2O)  Oct4NAuCl4 (Et2O)
nOct4NAuCl4(Et2O) + mRSH (tol) + 3nNaBH4  Aun(SR)m (tol)

28. Relationship between alkanethiolate polymer, nanocluster and self-assembled monolayer

29. SIZE SELECTIVE CRYSTALLIZATION OF SELF-ASSEMBLING AUROTHIOL CLUSTERS Aun(SR)m
Gradually adding a non-solvent such as acetone to a toluene solution of capped gold nanoclusters first causes larger crystals to precipitate, then smaller and smaller crystals, as the non-solvent concentration increases. Smaller ones more soluble because of easier solvation of less dense packed alkanethiolate chains.
When non-solvent added, nc-nc contacts become more favorable than nc-solvent interactions. Larger diameter capped gold nanoclusters interact via the chains of the alkanethiolate capping ligands more strongly than the smaller ones due to the smaller curvature of their surface and the resulting greater interaction area. As a result they are caused to flocculate that is aggregate and crystallize first.
Process repeated to obtain next lower size nanoclusters and procedure repeated to obtain monodispersed alkanethiolate capped gold nanoclusters.

30. CAPPED METAL CLUSTER CRYSTAL
CLUSTER SELF-ASSEMBLY DRIVEN BY HYDROPHOBIC INTERACTIONS BETWEEN ALKANE TAILS OF ALKANETHIOLATE CAPPING GROUPS ON GOLD NANOCRYSTALLITES
U.Landman AM 1996

31. Plasmonics Basics – Size Effects

32. Plasmonics Basics – Size Effects
What is the the surface plasmon resonance of gold nanostructures. On the top left corner is shown how the electron cloud of free-electrons in the gold respond to an oscillating electromagnetic field, depending on the shape and orientation of the particle. The formation of a dipole causes the emergence of a resonance at a specific wavelength, as shown on the right by the representative absorbance spectra. In the case of spherical particles the plasmon resonance occur at a single frequency, while for elongated nanocrystals you can have two resonance frequencies related with the two dipole oscillation modes (longitudinal or transverse).
In the bottom part of the Figure is shown the origin of the absorbance features according to the Mie theory. The absorbance A is expressed as the product of two terms. The first term is scattering-related and has a 1/l dependence, while the second term is exclusively dependent on the dielectric constants of the metal and the surrounding medium. This last term represent the resonant plasmon mode which is shown as a peak centered at the surface plasmon resonance wavelength lSPR. The product of the two terms is the spectrum observed experimentally.

33. SURFACE PLASMON RESONANCE MIE THEORY
Extinction coefficient from Mie theory is the exact solution to Maxwell’s electromagnetic field equations for a plane wave interacting with a homogenous sphere of radius R with the same dielectric constant as bulk metal (scattering and absorption contributions).
em is the dielectric constant of the surrounding medium – sensitive to environment
e = e1 + ie2 is the complex dielectric constant of the particle
Resonance peak occurs whenever the condition e1 = -2em is satisfied – sensitive to change in em of environment hence use as a surface plasmon sensor
This is the SPR peak which accounts for the brilliant colors of various metal nanoparticles – form factors can be introduced to account for non-spherical shape – Gans modification of Mie theory.

34. Extinction spectra calculated using Mie theory for gold nanospheres with diameters varying from 5 nm to 100 nm.

35. Detecting Biomolecules with Gold Nanocrystals Self Assembly and Plasmon Coupling

36. Detecting Biomolecules with Gold Nanocrystals Self Assembly and Plasmon Coupling
The coupling of plasmons can be used for the detection of oligonucleotides in solution. Gold nanocrystals can be produced with thiol-functionalized oligonucleotides bound to their surface – a construct which we call the probe. The oligonucleotides on the nanocrystals are synthesized to be complementary to the ones one wants to detect. The ultraspecific binding of oligonucleotides for their complementary strand allows the particles to bind very efficiently to the analytes in solution. Such binding of two nanocrystals to the same analyte brings the nanocrystals very close together thus enabling the coupling of the plasmons.
As shown in the diagram below, once the nanocrystals are close the dipole can extend over the ensemble of the two nanocrystals (as in resonance r2) while for single isolated particle the dipole is confined to the particle itself (resonance r1). The simultaneous presence of r1 and r2 resonances leads to an effective red shift of the absorbance peak of the nanocrystals thus changing their color, as shown in the photos thereby enabling detection of a specific oligonucleotide which shows complementary Watson-Crick base pairing.

37. Gold Nanocrystals to Gold Nanorods
Gold nanocrystal ncAu seed mediated growth of gold nanorods nrAu
ncAu seeds obtained by aqueous sodium borohydride reduction of HAuCl4 with sodium citrate surface stabilization
nrAu obtained by surfactant (trimethylcetylammonium bromide CTAB) directed re-growth of ncAu seeds using ascorbic acid mild reducing agent of HAuCl4

38. Non-Spherical Shapes -Gans Modified Mie Theory

39. Au Nanorods – Shape Selective Additives Aspect Ratio Tunes Longitudinal NOT Transverse SPR Modes
(a) L = 46 nm, w = 22 nm; (b) L = 61 nm, w = 22 nm; (c) L = 73 nm, w = 22 nm; (d) L = 75 nm, w = 22 nm; (e) L = 89 nm, w = 22 nm; (f) L = 108 nm, w = 22 nm. The right panel shows a representative TEM image of the sample corresponding to spectrum-f.
Calculated Gans Theory Gold Nanorod w = 20 nm

40. NANOCHEMISTRY CURES CANCER
Gold Nanorods Aspect Ratio Tunes Longitudinal NOT Transverse SPR Modes
NANOCHEMISTRY CURES CANCER
CANCER CELL TARGETED GOLD NANOROD ATTACHMENT
BURN AWAY THOSE NASTY CANCER CELLS BY NANORODS ABSORBING NIR PLASMON AND TRANSFERING HEAT TO CANCER CELL – PHOTOTHERMAL CANCER THERAPY

41. Nano Medicine - Photothermal Cancer Therapy Using Gold Nanorods

42. Nano Medicine Photothermal Cancer Therapy Using Gold Nanorods
In the top part of the Figure you can see how the plasmons relax back to the equilibrium state after being excited at their resonance. The relaxation occurs through emission of heat that can be used for killing cells to which they are selectively attached.
In the middle part of the Figure is shown from the left the absorption/scattering spectrum of the biological tissues and water; the windows of low absorbance are indicated by the pink areas. In the next spectrum is shown how the different absorbances of the tissues at different wavelengths affect the intensity of light propagating in them; as it is shown in the graph the light with wavelength 1000 nm will propagate further than light 500 nm, which is instead strongly absorbed. On the right is a representative absorbance spectrum of gold nanorods highlighting how the second resonance peak can be made to fit in the biological window, thus increasing its potential for photothermal therapy.
In the bottom part of the Figure are shown three different lines of cells (nonmalignant HaCat, malignant HSC and malignant HOC cells) after having exposed them to a strong NIR laser light (the circle highlights the area of exposure). The gold nanorods were made to bind selectively to the malignant cells thanks to an active targeting protocol. As you can see the nonmalignant cells were not harmed since they were not targeted by the nanorods. The malignant cells instead suffered strong damage because they were targeted by the nanorods and because the nanorods heated up upon irradiation with the laser.

44. CAPPED FePt FERROMAGNETIC NANOCLUSTER SUPERLATTICE HIGH-DENSITY DATA STORAGE MATERIALS

45. NANOMAGNETIC SEPARATIONS OF BIOLOGICAL MOLECULES