Unlocking The Potential of Nanoscience
and Technology Through Computational
Modeling
Robert Tshikhudo, PhD
Head: DST/Mintek NIC
07 December, 2011
Outline
• Background – Nanotechnology
• DST/Mintek Nanotechnology Innovation Centre (NIC):
Structure and Objectives
• Focused Modeling platforms in nanoscience- Motivation
• Some modeling examples
• Human capital development and outputs
• Future prospects
What/Why Nanotechnology ?
Def: Is the control and restructuring of matter at the nanoscale, at the
atomic and molecular levels in the size range of about 1–100 nm, in
order to create materials, devices, and systems with fundamentally
new properties and functions because of their small structure.
APPROCHES
SCALE OF THINGS
1 -100 nm
Top down
10-9m
Bottom up
Socio-Economic Benefits of Nano
Global Market of Products Incorporating Nano
Market of final products incorporating nanotechnology: the long term vision for
2000-2020 (solid line) and outcomes in 2009 (survey by Lux Research,)
DST Strategic Needs & Research
Water
• Purification
• Cost effective
source of energy
Energy
• Low cost solar cells
& batteries
• Alternative drug
delivery systems
Health
• Solutions to AIDS,
Malaria & TB
NANOTECHNOLOGY STRATEGY
• Effluent treated
• Coatings & paints for harsh
environments
Materials
• New materials for a
competitive industry
• Advanced tools using super
hard nanomaterials
• Beneficiation of minerals
Minerals
&
Mining
• Nano catalysts
• Cleaner production
technologies
SOCIAL CLUSTER
INDUSTRIAL CLUSTER
South Africa
Processing
NIC Operational Plan
Alignment to Strategic Objectives
Human Capital Development
Development of Research Platforms
Collaboration Plan
Convergence of different disciplines
Nanotechnology Innovation Centre
National facility
Three HEI nodes – 53 student
Three Science Councils
Annual workshop
Science Councils
(Involvement)
HEI’s
Involvement
DST Strategic Needs & Research: Social cluster
General Objectives
Research and Develop Nanostructured
Materials and their Applications in Health
(diagnostics and therapeutics) and Water
(monitoring and remediation)
NIC Framework
NIC
Health Platform
Biolabel Unit
Research
Group
Development
Group
Water Platform
Sensor Unit
Research
Group
Development
Group
Nanominerals Platform
Water Unit
Research
Group
Development
Group
Applied Science
Mintek
Marketing
and Uses
NPPPF
Product Development
Therapeutics
• Therapeutics
• Risk assessment
• ImagingSystems
Diagnostics
Water Treatment
• Lateral flow
• Electrochemical
• Systems
• Memb Systems
• Treatment
• Analysis
Design, Synthesis, Modeling, Characterisation, Services, Clean room facility, Validation
Core Nano
Nanominerals
Platforms
Fundamental science
TIA
Industry &
End-users
Development
Tech and product develop
Operational Strategy
Nanominerals platform
Focus Area:
The nanominerals platform focuses on undertaking fundamental nanoscience
research that supports the main objectives of NIC and focuses on synthesis,
characterization and modeling
Focused Modeling Platforms in
nanoscience- Motivation
Modeling Platforms
Platform 1: The nanomaterials
Anisotropic
Bimetallics
Which Materials?
- Metals
- Metal oxides
- Qdots
- Bimetallics
- Composites
How to make them? Why making them?
- Chemical reduction - Optical properties
- Biological synthesis - Catalytic properties
- Magnetic properties
- Redox reaction
- Mechanical
Modeling Platforms
Platform 2: Interaction & Functionalisation
Key issues:
• Solubility
• Stability
• Ligand size/type
• Biocompatibility
• Dispersity
• Ligand exchange
• Functionality
AUA
Functional group:
Calixarene
Nitrilotriacetic acid
Hydroxyl
Carboxyl
Azide
Amine etc
Ligand
Functionality
SA
DD
Modeling Platforms
Platform 3: Drug design and Molecular Recognition
Drug or Biomolecule
Key Issues
Target Markers
- Biomaker discovery
- Drug development
- Stability and chemistry
- Model interaction
- Proteins
- Sugars
- Nucleic acids
- Synthetic drugs
Conjugation
- Reactivity
- Functional
systems
Some Modeling
Examples
Selective Adsorption of PVP on Ag NPs
• Molecular dynamics study
• Use of polyvinyl pyrrolidone (PVP) as
surfactant to control the growth of Ag
nanoparticles
Selective Adsorption of PVP on Ag NPs
Intermediate complexes
TEM
a)
(a) Reaction mechanism and (b) reaction
profile versus energy for the formation of
isotropic and anisotropic silver
nanoparticles at room temperature and
under reflux.
PS Mdluli et al, Journal of molecular structure, 1004 (2011), 131
Selective Adsorption of PVP on Ag NPs
Molecular Dynamics Results
Interaction favoured through
oxygen of the carbonyl ends
Atomic density profile (%)
Optimised Ag-PVP adsorbed on each of the
surfaces (a) Ag(100)-PVP, (b) Ag(110)-PVP and
(c) Ag(111)-PVP complexes
12
(a)
10
Oxygen
Nitrogen
8
6
4
2
0
-2
0
5
10
15
20
25
30
35
40
Atomic density profile (%)
Distance from the surface (Å)
10
oxygen
(b)
nitrogen
8
6
4
2
0
-2
0
5
10
15
20
25
30
35
40
-320.2 kcal mol -1
-363.93 kcal mol -1
-355.3 kcal mol -1
Interaction energy values follows this trend:
Ag(110) > Ag (111) > Ag (100)
Atomic density profile (%)
Distance from the surface (Å)
18
16
14
12
10
8
6
4
2
0
-2
Oxygen
(c)
Nitrogen
0
5
PS Mdluli et al, Journal of molecular structure, 1004 (2011), 131
10
15
20
25
30
Distance from the surface (Å)
35
40
45
50
Gold nanoparticle interaction
with 3-thiopheneacetic acid
(3TAA)
N.M Sosibo et al, Journal of molecular structure, 1006 (2011), 4494
GNP interaction with 3-TAA
TEM
Semi-linear
Scheme showing five possible interactions of 3-TAA on GNP with the interaction
via (a) Carbonyl oxygen group, (b) both oxygen atoms on the carboxylic acid
end (c) One oxygen on the OH of carboxylic acid and thiophenyl group, (d) the
thiophenyl Group and (e) both oxygen and thiophenyl group
N.M Sosibo et al, Journal of molecular structure, 1006 (2011), 4494
GNP interaction with 3-TAA
Optimised Au-3-TAA
On each of the surface
a) Au(100)-3-TAA
b) Au (111)-3-TAA
c) Au (110)-3-TAA
Interaction energy values follows this trend:
Ag(111) > Ag (110) > Ag (100)
N.M Sosibo et al, Journal of molecular structure, 1006 (2011), 4494
Catalytic Reaction
Understanding selectivity of certain catalytic reaction
Gold-1-glycerol
Gold-2-glycerol
Gold-3-glycerol
Dr Thabani Ntho
Training by Acelrys
Catalysis
Gold
glycerol
Drug design and Molecular Recognition
The Design and Discovery of HIV-1 Integrase Inhibitors
Computer-aided drug design
- Molecular modelling of the viral enzyme
- Virtual screening of large compound libraries
- De novo drug design
Dr Raymond Hewer
Mphahlele et al. (2011), Bioorganic & Medicinal Chemistry.
DOI information: 10.1016/j.bmc.2011.10.072
Iron oxide interaction with 11Aminoundecanoic Acid (AUA)
and H2O
Richard H et al in press
1 nm Fe3O4 with AUA
1.2 nm Fe3O4 with AUA
2.6 nm Fe3O4 with AUA
Dr Richard Harris
1 nm Fe3O4 with H20
1.2 nm Fe3O4 with H20
HCD and Outputs
Human capital development
- Staff member at CHPC
- Six staff members
- Two student bursars
Scientific Outputs
- 2 MSc dissertations, 4 PhD thesis
- 8 conference contributions
- 6 journal articles
Summary
• Computational tools are important and required to
predict and understand properties, structures and
performance of nanostructured materials
• Need for human capital development in this area
Going forward…
• More networking and human capital
development in this area
• Extensive use of advanced computational
techniques for materials and life science
application
• Use of computational tools to predict the
toxicity of nanostructured materials
Acknowledgements
VARIOUS UNIVERSITIES
eg UL and UFS
Acknowledgements
Determined to improve the quality of life
Amanda
(Director)
Ndabenhle
Nanominerals Team
Biolabels Team
Phumlani
Hendriette Phumlani
Frankline
Busiswa
Sensors Team
Poslet
Kaushik
Richard
Water Team
Richard
(Director)
Sibulelo
(Director)
Philani
Mokae
Jessie
Keneiloe
Thabani
Philemon
Banele
Dumisani
Mogolodi
Thank you
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