Kristen A Fichthorn Department of Chemical Engineering Department of Physics Penn State University DEFG0207ER46414 Complex Nanostructures in Colloidal Crystal Growth How Do They Form ID: 242390
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Slide1
Multi-Scale Simulations of the Growth and Assembly of Colloidal Nanoscale Materials
Kristen A. FichthornDepartment of Chemical EngineeringDepartment of PhysicsPenn State University
DE-FG0207ER46414Slide2
Complex Nanostructures in Colloidal Crystal Growth: How Do They Form?
Ostwald Ripening
Cluster-Cluster
Aggregation
Oriented
Attachment
How Does OA Happen?Slide3
Complex Nanostructures in Colloidal Crystal Growth: Oriented Attachment
Oriented Attachment of TiO
2
:
Intrinsic Crystal Forces
Oriented Attachment and
the Mesocrystal State:
The Role of Solvent
R
. Penn and J.
Banfield
,
Geochim
.Cosmochim. Acta
63
, 1549 (1999).
M. Alimohammadi and K. Fichthorn, Nano
Lett
. 9,
4198 (2009).
V.
Yuwano
, N. Burrows, J.
Soltis
, and R. Penn,
JACS
132
, 2163 (2010).Slide4
Complex Nanostructures in Colloidal Crystal Growth: Capping Agents
Y. Sun, B.
Mayers
, T.
Herricks
, and
Y. Xia,
Nano
Lett
.
3
, 955 (2003).Slide5
Polyol
Process
Solvent:
Ethylene Glycol
Salt:
AgNO
3
“Stabilizer”:
PVP
What Happens
in the Pot?
B. Wiley,…Y. Xia,
Chem. Eur. J.
11
, 454
(2005).
“One-Pot” Solution-Phase Synthesis of Nanostructured
Metal Materials
N,N
-DMF Reduction
Solvent:
N,N
-DMF
Salt:
AgNO
3
“Stabilizer”:
PVP
All Kinds of
Nano
-Shapes
Heat at ~400 KSlide6
B. Wiley,…Y. Xia,
Chem. Eur. J. 11, 454 (2005).Reduction
of Ag
Nucleation
Growth
Nanostructure Formation:
General Aspects
Determined by
Salt and…
Solvent or PVP?
Probably Determined
by PVP…
Seed
FormationSlide7
Does
PVP Prefer Ag(100) Over Ag(111)?
Nanowires from Multiply-
Twinned DecahedralSeeds
Nanocubes from Single-
Crystal
Cubo
-Octahedral
Seeds
One Possible Role of PVP: Surface-Sensitive Binding
G.
Grochola
, I. Snook, and S. Russo,
J. Chem. Phys. 127, 194707 (2007).
Y. Sun, B.
Mayers
, T.
Herricks
, and Y. Xia,
Nano
Lett
.
3
, 955 (2003).Slide8
Interaction of PVP with Ag(100) and Ag(111):First-Principles Challenges
Direct Bonding +van der Waals (vdW)
vdW
Historically DFT Described Direct Bonds,
Including vdW Interactions is
New…
S.
Grimme,
J.
Comput
. Chem.
27, 1787 (2006).M. Dion,…, D. C. Langreth, B. I.
Lundqvist, Phys. Rev. Lett
.
92, 246401 (2004).
A. Tkatchenko
and M. Scheffler,
Phys. Rev.
Lett.
102
, 073005 (2009).
K. Lee, …, D. C.
Langreth
, B. I.
Lundqvist
,
Phys. Rev. B
82
, 081101 (2010).
L.
Delle
Site, K. Kremer,
Int. J. Quant. Chem.
101
, 733 (2005).
n
Coarse-Grained
ModelSlide9
Interaction of PVP with Ag(100) and Ag(111): VASP 5.2.11
(4×4×14) Super Cell Slab: 6
layersVacuum
: 8 layers
PAW-PBE (GGA) ± DFT-D2 ± TS*
Assess the Influence of
vdW
Interactions
Cut-off
: 29.4
Ry
k-points: (4×4×1)
Ab-initio Molecular DynamicsStatic Total-Energy Calculations
*Implemented in VASP
by Wissam Al-SaidiSlide10
van der Waals Interactions in DFT: How Do We Describe Ag??
aS. Grimme, J.
Comput. Chem.
27, 1787 (2006).
b
A
. Tkatchenko and M. Scheffler,
Phys. Rev.
Lett.
102
, 073005 (2009) .
c
E. Zaremba and W. Kohn, Phys. Rev. B
13, 2279 (1976).dS
.
Eichenlaub, C. Chan, and S. P.
Beaudoin,
J. Coll. Int. Sci.
248
, 389 (2002).e
A.
Khein
, D. J. Singh, and C. J.
Umrigar
,
Phys. Rev. B
51
, 4105, (1995).
f
H
. Li,
et al.
,
Phys. Rev. B
43
, 7305 (1991).
g
F. R. De Boer, et al., Cohesion in Metals, Amsterdam, (1988).h
M. Chelvayohan and C.H.B. Mee,
J. Phys. C: Solid State Phys.15, 2305 (1982).
PBE
DFT-D2
a
TS+ZK
b+c
Experiment
C
6
(J nm6
mol-1)
---
24.67
6.89
6.25d
R
0(Å)
---
1.64
1.34
---
aAg (Å)
4.16
4.15
4.02
4.07
e
D12
Ag(100) (%)
-2.05
1.3
-1.75
±1.5
f,g
D
12 Ag(111) (%)
-0.3
1.61
-0.32
0.5 ± 0.8
hSlide11
Binding Conformations:
No vdW InteractionsExperimental IR and XPS:PVP Binds to Ag via the O and/or N Atom.
Ag(100)
Top
Hollow
Bridge
Ag(111)
Top
fcc
Hollow
hcp
Hollow
Bridge
Trial & Error:
Bonding with O Atom Down
F.
Bonet
et al
.,
Bull. Mater. Sci.
23
, 165 (2000).
Z. Zhang
et al
.,
J. Solid State Chem.
121
, 105 (
1996).
H. H. Huang
et al
.,
Langmuir
12
, 909 (1996).Slide12
Binding Energies: No vdW Interactions
Adsorption site
Ethane
2-Pyrrolidone
(100) Hollow
0.0
0.19
(100) Bridge
0.0
0.22
(100) Top
-
0.21
(111)
fcc
Hollow
0.0
0.19
(111)
hcp
Hollow
-
0.16
(111) Bridge
-
0.20
(111) Top
-
0.26
Bond Strength (
eV
)
P
redominantly
vdW
Ag(100)
Top
Hollow
Bridge
Ag(111)
Top
fcc
Hollow
hcp
Hollow
Bridge
Preference for Ag(111): Contrary to Expectations
Ethane Binds:
X.-L. Zhou and J. M. White,
J. Phys. Chem.
96
, 7703 (1992).Slide13
vdW
Interactions Support Structure-Directing Hypothesis
Site
PBE
PBE
DFT-D2
PBE
TS+ZK
(100) Hollow
0.19
1.05
0.59
(100) Bridge
0.22
1.34
0.77
(100) Top
0.21
1.05
0.60
(111)
fcc
0.19
0.61
0.58
(111)
hcp
0.16
0.80
0.58
(111) Bridge
0.20
0.70
0.62
(111) Top
0.26
0.79
0.64
Bond Strength (
eV
)
Why Such Big Differences Between Methods??Slide14
DFT-D2: Ag(100) Reconstructs
Ag(100) Reconstruction has not been Observed Experimentally…Slide15
TS+ZK:2-Pyrrolidone on Ag(100)
HollowEbind
= 0.59
Bridge
E
bind
=
0.77
Top
Ebind
= 0.60
Hollow ||
E
bind
=
0.77
Bridge ||
E
bind
=
0.81
Top ||
E
bind
=
0.78
Lots of Options!
Binding via O and N
F.
Bonet
et al
.,
Bull. Mater. Sci.
23 (2000).Z. Zhang et al.,
J. Solid State Chem.
121 (1996).H. H. Huang et al
., Langmuir 12 (1996).Slide16
PVP ~139 Times More Likely to Bind to
Ag(100) “Sides” than Ag(111) “Ends”Slide17
TS+ZK Energies
TS+ZK Geometries
PBE Energies
TS+ZK Geometries
D
Site
E
bind
E
Pauli
+E
direct
bond
E
vdW
(100) Hollow ||
0.78
0.36
0.42
(100) Bridge ||
0.81
0.32
0.48
(100) Top ||
0.77
0.30
0.47
(111) Top
┴
0.64
0.12
0.51
(111) Bridge
┴
0.62
0.09
0.53
(111) Bridge ||
0.63
-0.19
0.82
TS+ZK Method: Break-Down
of Binding EnergySlide18
TS+ZK Energies
TS+ZK Geometries
PBE Energies
TS+ZK Geometries
D
Site
E
bind
E
Pauli
+E
direct
bond
E
vdW
(100) Hollow ||
0.78
0.36
0.42
(100) Bridge ||
0.81
0.32
0.48
(100) Top ||
0.77
0.30
0.47
(111) Top
┴
0.64
0.12
0.51
(111) Bridge
┴
0.62
0.09
0.53
(111) Bridge ||
0.63
-0.19
0.82
TS+ZK Method: Break-Down
of Binding Energy
Ag(100):
vdW
and Direct Bonding SynergizeSlide19
TS+ZK Energies
TS+ZK Geometries
PBE Energies
TS+ZK Geometries
D
Site
E
bind
E
Pauli
+E
direct
bond
E
vdW
(100) Hollow ||
0.78
0.36
0.42
(100) Bridge ||
0.81
0.32
0.48
(100) Top||
0.77
0.30
0.47
(111) Top
┴
0.64
0.12
0.51
(111) Bridge
┴
0.62
0.09
0.53
(111) Bridge ||
0.63
-0.19
0.82
TS+ZK Method: Break-Down
of Binding Energy
Ag(111):
vdW
is the Dominant Attractive Force
Sometimes the
only
Attractive ForceSlide20
We Observed Stronger Binding to
Ag(100) when we Include vdW As Inferred by Experiment
Conclusions
We Studied
Surface-Sensitivity
of
PVP Binding to Ag(111) and Ag(100)
DFT-D2 Reconstructs Ag(100)
Ag(100) Preference from Synergy Between
vdW
Attraction and Direct Bonding Slide21
Oriented Attachment
in Crystal Growth:Role of Intrinsic Crystal ForcesSee Also:M. Niederberger and H. Cölfen, Phys. Chem. Chem. Phys. 8
, 3271 (2006). Q. Zhang, S. Liu, and S. Yu, J. Mater. Chem. 19, 191 (2009).
HRTEM:
Oriented Attachment
of
TiO2 Nanoparticles
R. Penn and J. Banfield
, Geochim. Cosmochim.Acta
63, 1549 (1999).Slide22
Dipole-Dipole Interactions May
Assemble NanoparticlesT. Zhang, N. Kotov, and S. Glotzer, Nano Lett.
7, 1670 (2007).
Z. Tang and N. Kotov
,
Adv. Mater. 17, 951 (2005);
Z. Tang, N. Kotov, M.
Giersig
, Science 297, 237 (2002).
CdTe
Nanoparticle Chains
+ -
+ -Slide23
Two Wulff
Nanocrystals
(001) Truncated
Nanocrystals
(112) Truncated
Nanocrystals
m
=35 D
m
=0
m
=250 D
m
=75 D
TiO
2
(Anatase) Nanocrystals
Matsui-
Akaogi
Force Field
Mol.
Sim
. 6, 239, 1991.
*Slide24
Aggregation of Wulff NanocrystalsSlide25
Nanocrystal Aggregation:The Hinge Mechanism
Initial Contact of Edges:The “Hinge”Rotation About the “Hinge”Slide26
Nanocrystal Aggregation:
Driven by Electrostatic ForcesM. Alimohammadi and K. Fichthorn,
Nano Lett
. 9,
4198 (2009).Slide27
Nanocrystal Aggregation: Driven by Multipoles from Under-Coordinated
Surface AtomsM. Alimohammadi and K. Fichthorn, Nano Lett. 9,
4198 (2009).Slide28
HRTEM Image Showing Oriented Attachment of 5 TiO
2 NanoparticlesR. Penn and J. Banfield, Geochim. Cosmochim. Acta 63, 1549 (1999).
Simulation vs. Experiment:
Still Have a Way to Go
Aqueous Environment
Hour (or longer) Times
Vacuum Environment
Nanosecond TimesSlide29
Nanocrystal Aggregation is Driven by Local Interactions.We Should Re-Think the Dipole Idea…
ConclusionsP. Schapotschnikow
et al.,
Nano Lett
.
10, 3966 (2010).
Also found this for capped and uncapped PbSe…Slide30
1D Nanostructures form via
Mesocrystals and Oriented Attachment
M. Giersig, I.
Pastoriza-Santos, L. Liz-Marzan,J. Mater. Chem.
14, 607 (2004).
Ag Nanowires
V.
Yuwano
, …, and R. Penn,
JACS
132
, 2163 (2010).
Goethite NanowiresSlide31
Solvent Ordering and
Solvation ForcesSolvent Density ProfileSolvent ordering around solvophilic
nanoparticles
Y. Qin and K. A. Fichthorn,
J. Chem. Phys
.
119
, 9745 (2003).
Y. Qin and K. A. Fichthorn,
Phys. Rev. E
7
3
, 020401 (2006).Slide32
MD: Aggregation of a Small, Isotropic*Crystal with a Larger, Anisotropic Crystal
*Relatively
Rectangular
Cuboid
Square
Plate
2
1
3
2
1
●
Generic Anisotropic
fcc
Nanoparticles
●
Solvophilic
Nanoparticles
●
Strong
vdW
Attraction (Ag)
●
Isotropic Organic SolventSlide33
Aggregation of Small and Large Nanocrystals: Mesocrystal
States
Mesocrystal
State 1One Solvent Layer
Mesocrystal
State 1One Solvent Layer
Mesocrystal State 2Two Solvent LayersSlide34
Mesocrystal
States: Free-Energy Minima
Escape-Time Distribution
Aggregation Probability
Aggregation of Small and Large Nanocrystals:
Mesocrystal
States
Mesocrystal
State 1
One Solvent Layer
Mesocrystal
State 1
One Solvent Layer
Mesocrystal
State 2
Two Solvent LayersSlide35
Aggregation:
Fastest at End of RectangleSlowest on Face of SquareEven on Sides
Mesocrystal State 1Most Frequent
Mesocrystal State 2Occurs on Square
Mesocrystal
State 3
DissociationNot Typically Frequent
Dissociation
Nanocrystal Encounters:
Frequency of Outcomes
3
1
2
1
2
Aggregation is the Most Frequent
On the Smallest Facets,
Perpetuating 1D GrowthSlide36
Disruption Solvent Ordering at EdgesLeads to Fast Aggregation on Small Facets
Square PlateRectangle
7.2
6.6
6.0
5.4
4.8
4.23.6
3.02.41.81.2
0.60
r/
r
b
RectangleSlide37
Conclusions
Solvent Ordering Around Nanocrystal SurfacesPromotes Growth of 1D NanostructuresLeads to Mesocrystal
States
Faster Aggregation on Smaller FacetsSlide38
Collaborators
FundingNSF DMR-1006452, NIRT CCR-0303976, CBET-0730987DOE
DE-FG0207ER46414ACS, EPA, NCSA
Mozhgan
Alimohammadi
Haijun FengAzar Shahraz
Jin Pyo HongDr. Ya Zhou
Dr. Yangzheng Lin
Alums
Dr. Yong
Qin
Dr. Rajesh SathiyanarayananDr. Leonidas
GergidisFritz Haber InstituteAlexander TkatchenkoVictor Gonzalo Ruiz Lopez
Matthias SchefflerUniv. of PittsburghDr. Wissam Al-Saidi