Prep I II NanoChem2015 - · PDF fileComputational Model for Nanoparticle Synthesis Using...

Nanochemistry

Andreas Borgschulte([email protected])

Preparation of nanostructures

CHE729

Mi. 10:00-11:45

Introduction: Preparation of nano structures Bottom-up approach top-down approach

Methods lithography ball-milling nano-structured hydride Nanostructures by casting Nanoparticles from precipitation reaction surface functionalization sol-gel preparation Laser ablation Pyrolysis sputtering

Self-organizing / self-assembly

Contents of this lecture

http://www.nanoscience.at

Preparation of nano structures

The ‘top-down’ approach

The ‘bottom-up’ approach

structuring matter

self-assembly

Memory Chip

Lithography at 13.5 nanometers (EUV) (Zeiss)

Photolithography for nano structures (Top-down)

substrate

functional layerphotoresist

picture from wikipedia

Two-dimensional arrays of high refractive index structures can be fabricated using a combination of e- beam lithography for pattern definition and electrochemical deposition for structure formation. The potential of this method is demonstrated for CdSe, where (a)

mushrooms, (b) nanopillars, (c) walls, and (d) crosses are prepared. Such arrays have potential in optical device applications such as photonic crystals and waveguides. [Advanced Materials, 15, 49

(2003)]

An SEM image of a single electron transistor. The source and drain electrodes are bridged by C60-Au- C60 nano-

particles. The gate electrode is not shown. The inset shows the suspended Au leads before attachment of Au particles. The width of the electrodes is about 160 nm, and the gap between the two tips is about 15 nm. The scale bar is 100

nm. [Applied Physics Letters, 81, 4595 (2002)]

State of the art Electron lithography (Top-down)

The quantum corral reef -An academic gadget (Eigler et al. IBM)

Nanostructuring on atomic length scale (Bottom-up)

expensive methods mass fabrication?

0 10 20 30 400

10

20

30

40

50

Ti(C,N)-phase Ni-phase

sche

rrer

cry

stal

lite

size

[nm

]

m illing time [h]

Nanostructuring by ball milling (Top-down)

Courtesy Nico Eigen

GG

Reduction of crystallite size Formation of -MgH2 Cycling: grain size back to 80 nm Kinetics improved Additives: surface/bulk effect?

Ball-milling: nanostructuring on industrial scale (Top-down)

Ball-milling of MgH2

0 1 2 3 4 5 6 7 8 9 10 11

0

20

40

60

80

100

120

140

160

180

grai

n si

ze (n

m)

milling time (h)

P.-A. Huhn, et al., J. Alloys Compd. 404 (2005) 499, A. Borgschulte et al., Catalysis Today 120 (2007) 262

6000400020000

20 h120 h200 h

8

7

6

5

4

3

2

1

010005000

8

7

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5

4

3

2

1

0

H2-

cont

ent [

wt.%

]

time [s]

20 h

200 h

coarse-grained

time [s]

nanocrystalline microstructure fast kinetics

T = 300°Cp = 8 bar p = 10-3 mbar

coarse-grained

Kinetics of MgH2: Effect of Milling Time

Courtesy Thomas Klassen

Nanostructured Hydrides

LaNi5Hx kinetics

ball milled

as cast

M. Fichtner, AEM 7, 449 (2005)

improved kinetics Hydride phase confined by

nanoscaffolds / ligands (reduces sintering and growth)

Nanoscale confinement may alter thermodynamics of hydride

Dehydrogenation of LiBH4/MgH2. (a) Bulk (b)/ (c) 2LiBH4 + MgH2 incorporated sequentially/simultaneously into a 13nm mode pore size carbon aerogel. J.J. Vajo / Current Opinion in Solid State and

Materials Science 15 (2011) 52–61

Meganne L. Christian and Kondo-François Aguey-Zinsou, ACS Nano,

2012, 6 (9), pp 7739

Nanostructuring by “Casting”

Jongmin Lee, J. Mater. Chem., 2009, 19, 7050

Pd Clusters: d[nm]Pd55phen*

36O30 Pd2 1.0Pd561phen*

36O200 Pd5 2.6Pd1415phen*

60O1100 Pd7 3.7Pd2057phen*

20O1600 Pd8 4.2

Ligand shell formation (Phenanthroline)

Cluster formation (PdIIacetate + hydrogen gas)

PdIIacetate + H2

Pd + acetic acid

Ref.: G. Schmid, J. Am. Chem. Soc. 115 (1993), pp. 2046

Synthesis of Pd-clusters (Bottom-up)

Courtesy Züttel

15

XRD of stabilized Pd-clusters

n is the number of shells

Ligand shell: Phenanthroline

-140

-120

-100

-80

-60

-40

-20

0

-E0 [m

V]

0.50.010-5

10-4

10-3

10-2

10-1

100

p [bar]

1500

0.50.0

1500

0.50.0c [H/M]

1500C [mAh·g-1]

0.50.0

1500

pc-Isothermes of H in Pd-Clusters

Pd2Pd5Pd bulk (fcc) Pd7/8

Ref.: A Züttel, et al., Applied Surface Science 162-163 (2000), pp. 571-575

Narrowing of the Pd-H miscibility gap.

Ball-milling: grain refinement nano-clusters hydride thin films impregnation of nano-scaffolds core-shell hydride nanostructures

Nanostructured Hydrides

Huge thermodynamic overpressure (∆G<<0) slow diffusion (relative to number of seeds):

L2r >> D Ouzo effect

Bottom – up approach for the Preparation of particles

Sitnikova, N. et al. Langmuir 21, 7083 (2005)

L=

Pd-acetate AgNO3 AuCl4H H2PtCl6·6H2O Ni(NO3)2·6H2O CuSO4 …

Metal Nanoparticles from precipitation reaction

Metal salt

KBH4 ascorbic acid trisodium citrate

dihydrate hydrogen …

reductant

+

=metal nano particles

Professional preparation of Nanoparticles from precipitation reaction

Control of salt/reductant Control of pH Control of temperature Additional compounds:

support (co-precipitation), stabilizers, surfactants

Additional preparation steps: drying, annealing etc…

Fast reduction of AgNO3 enlarges a Ag nanocube along the [100] directions by preferentially depositing Ag atoms onto the {100} side faces. Consequently, concave structures are produced on the newly formed {111} facets.

When Cu2+ ions are introduced, growth is dominated by the [111] directions, forcing the cubic seed to sequentially evolve into a concave cube, an octapod, and finally a concave trisoctahedron, with all of them being enclosed by high-index facets.

Xiaohu Xia, et al., Angew. Chem. Int. Ed. 2011, 50, 12542

Controlling the growth and shape of nano-clusters

physical methods (see above, lecture Surface Science)

chemically: silica: etching with HF, chlorosilane etc. carbon:

fluorination, Gringard reagents, nitrenes (R-OOC-N3), Bingel’s reaction: BrC()(COOEt)2 reacts with CNT

(iron)oxide: surface ligands, hydrolysis (pH!)

Surface modifications (“functionalization”)

Yi-Cheun Yeh, et al., Nanoscale, 2012, 4, 1871

Gold nanoparticles in bionanotechnology

hydrolysis of tetraethoxyorthosilicate (TEOS) in EtOH/H2O: (RO)3Si-OR + H2O => (RO)3Si-OH + ROH

condensation: (RO)3Si-OH + RO-Si(RO)3 => (RO)3Si-O-Si(RO)3 + ROH (RO)3Si-OH + HO-Si(RO)3 => (RO)3Si-O-Si(RO)3 + H2O

Stöber synthesis of Silica sol-gels

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using defined number of seeds (e.g. Au nano particles), one can control the size

The shell thicknesses are (a, top left) 10 nm, (b, top right) 23 nm, (c, bottom left) 58 nm, and (d, bottom right) 83 nm

Luis M. Liz-Marzan, et al. Langmuir 1996, 12, 4329-4335

Synthesis of Nanosized Gold-Silica Core-Shell Particles

sol-gel reaction





Nano-particles generated during combustion

Pictures from wikipedia

Soot production by incomplete combustion via

Boudouard reaction:2CO C + CO2

decomposition of hydrocarbons: CnHm n C + m/2 H2

Venkatramanan Raman, Rodney O. Fox and Mark Gordon, Development of a Predictive Multiphysics Computational Model for Nanoparticle Synthesis Using Flame-Spray Pyrolysis, NSF Research Proposal

(2007).

ETH

Spray pyrolysis

Laser irradiation of nanoparticles

Barcikowski, Laser Zentrum Hannover

Barcikowski et al., COLA 2007

Synthesis of magnetic nano-particles

Magnetic Fe3O4 particles immersed in aceton

V. Amendola and M. Meneghetti, Phys. Chem. Chem. Phys., 2013, 15, 3027

Physical processes in Laser ablation


Time Line

P. Lorazo, L. J. Lewis and M. Meunier, Phys. Rev. B:Condens. Matter Mater. Phys., 2006, 73, 134108.

C. Momma, et al., Opt. Commun., 1996, 129, 134–142.

T. Tsuji, et al., Appl. Surf. Sci., 2008, 254, 5224.

Model experiments / calculations


Target material for laser ablation


Generated particles depend on Target material + Solvent



Metal salt

NaBH4 ascorbic acid trisodium citrate


reductant

+


G. Medeiros-Ribeiro et al., Phys. Rev. B 58, 3533 (1998)

external transport

homogeneous nuleationheterogeneous

adsorption-desorption

Cluster-kinetics

surface-diffusion

growth- kinetics

Nanostructuring by thin film technology

physical vapor deposition (bottom-up) chemical vapor deposition (bottom-up) sputtering (bottom-up) electrochemistry (bottom-up) ion etching (top-down) (photo-)lithography (top-down)

lecture surface science:self-organized thin film growth

THE method for (industrial) thin film deposition => heterogeneous cluster nucleation

Atoms in the plasma may cool down and condense into clusters => homogenous cluster nucleation

Ion sputtering

external transport



Cluster-kinetics

surface-diffusion

growth- kinetics

Ion and cluster implantation

Ion ‘etching’ lithography depth profiling

Secondary ion mass spectrometry

Ion sputtering

Formation of Metallic Nanoparticlesin Silicate Glass through Ion Implantation,

A. L. Stepanov, V. N. Popok, and D. E. Hole, Glass Physics and Chemistry, Vol. 28, No. 2,

2002, pp. 90–95.

Ion sputtering: Depth profiling

surface segregation

S. Kato et al., Phys. Chem. Chem. Phys., 2012, 14, 5518

+ - -

-

e-

-

+

THE method for (industrial) thin film deposition

Atoms in the plasma may cool down and condense into clusters

(Magnetron) sputtering

Bernard Dam

Sputtering system for new H storage materials

Preparation of nano clusters by sputtering

Thesis Elsa Callini

C. G. Granqvist and R. A. Buhrman, J. Appl. Phys. 47, 2200 (1976)

Size of clusters depends on background pressure

1st step: nucleation of particles

2nd step: growth of particles

Atomically defined Nano clusters

AG Ganteför, University Konstanz

E. M. Fernandez, J. M. Soler, I. L. Garzon und L. C. Balbas. Trends in the structure and bonding of noble metal clusters. Phys. Rev. B, 70(16), 165403, (2004).

Structure of small Au-clusters

49

icosahedronMagic numbers:13, 55, 147, 309, 561, 923…corners: 12edges: 30faces: 20

Wulff-polyhedronMagic numbers:33, 155, 427, 909, 1661, …corners: 24edges: 36faces: 14

fcc-cubeMagic numbers:14, 63, 172, 365, 666, 1099…corners: 8edges: 12faces: 6

cuboctahedronMagic numbers:13, 55, 147, 309, 561, 923…corners: 12edges: 24faces: 14

octahedronMagic numbers:7, 25, 63, 129, 231, 377…corners: 6edges: 12faces: 8

ar

23ar

21ar

55241ar

25ar

From 1D-structures to 2D structures

What is the Stöber reaction? Minimum/Maximum k-vector in a lattice? Wulff-construction? Why do we need seeds for nucleation? What is the electro-chemical double layer? Rule of thumb: Critical size for nano-effects? Nano-second lasers are much cheaper than

pico/femto second lasers, but not suitable for drilling, generation of nano-particles, why?

What are magic numbers?

You are the better teachers (I hope)…

Huge thermodynamic overpressure (∆G<<0) slow diffusion (relative to number of seeds):

L2r >> D Ouzo effect

Bottom – up approach for the Preparation of particles

Sitnikova, N. et al. Langmuir 21, 7083 (2005)

L=



Metal salt

NaBH4 ascorbic acid trisodium citrate


reductant

+


Self-assembly can be defined as the spontaneous and reversible organization of molecular units into ordered structures by non-covalent interactions. The first property of a self-assembled system that this definition suggests is the spontaneity of the self-assembly process: the interactions responsible for the formation of the self-assembled system act on a strictly local level—in other words, the (nano)structure builds itself. (wikipedia)

Self-organization is a process where some form of global order or coordination arises out of the local interactions between the components of an initially disordered system. This process is spontaneous: it is not directed or controlled by any agent or subsystem inside or outside of the system; however, the laws followed by the process and its initial conditions may have been chosen or caused by an agent. It is often triggered by random fluctuations that are amplified by positive feedback. (wikipedia)

Self-assembly / Self-organization

Pattern formation

Molten tin solidifies in a pattern of dendrites

wikipedia

"Sierpinski triangle evolution" by Wereon, Wikipedia

The Sierpinski triangle may be constructed from an equilateral triangle by repeated removal of triangular subsets:

Start with an equilateral triangle.Subdivide it into four smaller congruent equilateral triangles and remove the

central one.Repeat step 2 with each of the remaining smaller triangles

Fractals

A fractal is a natural phenomenon or a mathematical setthat exhibits a repeating pattern that displays at everyscale. If the replication is exactly the same at every scale,it is called a self-similar pattern.

Spatio-temporal Patterns in Liquid Crystals

a) Gas discharge caused by ac. b) Electroluminescence pattern in an ac-driven ZnS: Mg semiconductor layer system. c) Chemical (Belousov-Zhabotinsky) reaction. d) Optical system with Na-vapor as nonlinear medium. e) c-ADP density waves of an amoeba population. f) Ca-waves on frog eggs. (from Scholarpedia; after Purwins, H.G. et al. (2007)).

Spiral formation in non-equilibrium systems

12222

21111 , nen

dtdnnen

dtdn

Lotka–Volterra equation

Kormondy, Concepts of Ecology, Englewood Cliffs, N.J. 1976)

12222

21111 , nen

dtdnnen

dtdn

Oscillations during CO oxidation

R. Schwankner, … G. Ertl, J. Chem. Phys. 87, 742 (1987);Y. Chabal et al., Princeton

Coupling oscillating chemical reactions on the microscale

Chemische Oszillationen in einzelnen Tropfen, in denen die Belouzov-Zhabotinski-Reaktion abläuft. Die farbigen Kurven geben die optische Transmission in den drei Tropfen wieder, die als Indikator für die chemische Reaktion dient. Die schwarze Kurve zeigt den Abstand der Mittelpunkte des zur blauen und zur roten Kurve gehörenden Tropfens. Bei etwa 120 Sekunden bildet sich spontan die Lipiddoppelschicht. Obwohl die Tropfen bereits vorher in Kontakt stehen, sind die chemischen Oszillationen außer Phase. Erst nach Bildung der Membran wird eine starre Phasenkopplung beobachtet.© Max-Planck-Institut für Dynamik und Selbstorganisation

Where is the nano?

Self-assembly of preformed Au and TiO2 nanoparticles into multicomponent 3D aerogels

F. Heiligtag, et al, J. Mater. Chem., 2011, 21, 16893–16899

external transport



Cluster-kinetics

surface-diffusion

growth- kinetics

Crystal Growth from the gas phase: this is self-assembly

ad/desorption surface diffusion growth kinetics

Self-assembly on Au surfaces

Colin D. Bain , E. Barry Troughton , Yu Tai Tao , Joseph Evall , George M. Whitesides , Ralph G. NuzzoJ. Am. Chem. Soc., 1989, 111 (1), pp. 321; pictures from https://www.ifm.liu.se/applphys/molphys/research/self/(Linköping University)

Au(111)

Characteristics of a Self assembled Monolayers (SAM) of alkanethiolates on Au (111)

E. Pensa, E.C., G. Corthey, P. Carro, C. Vericat, M.H. Fonticelli, G. Benìtez, A.A. Rubert, and R. C. Salvarezza, The Chemistry of the Sulfur-Gold Interface: In Search of a Unified Model, Accounts of chemical research, 2012. 45

H. Imahori, Giant Multiporphyrin Arrays as Artificial Light-Harvesting Antennas, J. Phys. Chem. B 108 6130 (2004)

SAM as Artificial Light-Harvesting Antennas

Yi-Cheun Yeh, et al., Nanoscale, 2012, 4, 1871

Gold nanoparticles in bionanotechnology

Picture: wikipedia; Lit.: Katsuhiko Ariga, Jonathan P Hill, Michael V Lee, Ajayan Vinu, Richard Charvet and Somobrata Acharya, Sci. Technol. Adv. Mater. 9 (2008) 014109

Self-assembly on water

Langmuir-Blodgett-film Langmuir-trough

water

2D-polymers formed in a “Langmuir trough”

UV-polymerization

P. Payamyar, M. Servalli, T. Hungerland, A. Schütz, Z. Zheng, A. Borgschulte, A. D. Schlüter, Macromol. Rapid Commun., 2015; 321–335; Katsuhiko Ariga, Jonathan P Hill, Michael V Lee, Ajayan Vinu, Richard Charvet and Somobrata Acharya, Sci. Technol. Adv. Mater. 9 (2008) 014109

Schlüter group ETH

Self-organization producing micelles

e.g. surfactants Hydrophilic head group

Hydrophobic tail

Spherical micelle

water

oil

oil

oil

oil oil

Courtesy Zoe Schnepp


TEOS-hydrolysis


calcination

Jia Liu et al., Microporous and Mesoporous Materials (2009)

Coppens M-O, Curr Opin Chem Eng (2012), doi:10.1016/j.coche.2012.03.002

Bionic

http://www.biologycorner.com/resources/DNA-colored.gif

Sugar phosphate

backbone

Bottom-up approach in nature

Guanine Cytosine

Adenine ThymineCourtesy Zoe Schnepp

wikipedia





18.02.2015 Introduction 25.02.2015 Measurement of Nanostructures I 04.03.2015 Measurement of Nanostructures II 11.03.2015 Optical Properties 18.03.2015 Surface Science I 25.03.2015 Surface Science II 01.04.2015 Preparation of nano structures I 15.04.2015 Preparation of nano structures II 22.04.2015 Applications I: Catalysis 29.04.2015 Seminars 06.05.2015 Applications II: Wetting, Colloids, Seminars 13.05.2015 Theory, Seminars 20.05.2015 cell biology / Nanotoxicity, Seminars 27.05.2015 Applications III: Energy

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