atomic & molecular nanotechnology
DESCRIPTION
Atomic & Molecular Nanotechnology. G. Ali Mansoori , Bio & Chem Eng; Depts Prime Grant Support: ARO, KU, UMSL, ANL. Experimental and theoretical studies of organic nanostructures derived from petroleum ( Diamondoids , asphaltenes , etc.).. - PowerPoint PPT PresentationTRANSCRIPT
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Atomic & Molecular NanotechnologyG. Ali Mansoori, Bio & Chem Eng; Depts
Prime Grant Support: ARO, KU, UMSL, ANL
• Experimental and theoretical studies of organic nanostructures derived from petroleum (Diamondoids, asphaltenes, etc.)..
• Quantum and statistical mechanics of small systems - Development of ab initio models and equations of state of nanosystems. Phase transitions, fragmentations.
• Molecular dynamics simulation of small systems - Studies in non-extensivity and internal pressure anomaly of nanosystems.
• DNA-Dendrimers nano-cluster formation, nanoparticle-protein attachment for drug delivery
• DNA-Dendrimer Nano-Cluster Electrostatics (CTNS, 2005)
• Nonextensivity and Nonintensivity in Nanosystems - A Molecular Dynamics Sumulation J Comput & Theort Nanoscience (CTNS,2005)
• Principles of Nanotechnology (Book) World Scientific Pub. Co (2005)
• Statistical Mechanical Modeling and its Application to Nanosystems Handbook of Theor & Comput Nanoscience and Nanotechnology (2005)
• Phase-Transition and Fragmentation in Nano-Confined Fluids J Comput & Theort Nanoscience (2005)
• Interatomic Potential Models for Nanostructures" Encycl Nanoscience & Nanotechnology (2004)
• Nanoparticles-Protein Attachmrnt
• Nano-Imaging (AFM & STM), Microelectrophoresis
• Ab Initio computations (Applications of Gaussian 98)
• Nano-Systems Simulations (Molecular Dynamics)
• Nano-Thermodynamics and Statistical Mechanics
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Fundamental Design of NanocatalystsRandall J. Meyer, Chemical Engineering Department
Prime Grant Support: NSF, PRF
• Finite fossil fuel reserves dictate that new solutions must be found to reduce energy consumption and decrease carbon use
• New processes must be developed to handle renewable feedstocks
• Current design of catalysts is often done through trial and error or through combinatorial methods without deep fundamental understanding
• Our group seeks to combine experimental and theoretical methods to provide rational catalyst design
• Explained the molecular basis of conduction mechanisms of ions in ClC.
• Used this improved understanding to predict behavior of ions in ClC.
• Used molecular simulation to explain the permeation mechanism of ions in ClC.
• Use molecular simulations to model the permeation of ions in chloride ion channels.
• Examine the effects of the architecture of the tube surface on the water molecules in the tube.
• Determine reorientation correlation times of water molecules of the first hydration shell of the ions in ion channels and in the bulk solution.
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Molecular Simulation of Gas SeparationsSohail Murad, Chemical Engineering Department
Prime Grant Support: US National Science Foundation
• Understand The Molecular Basis For Membrane Based Gas Separations
• Explain At The Fundamental Molecular Level Why Membranes Allow Certain Gases To Permeate Faster than Others
• Use This Information To Develop Strategies For Better Design Of Membrane Based Gas Separation Processes For New Applications.
• Explained The Molecular Basis Of Separation of N2/O2 and N2/CO2 Mixtures Using a Range of Zeolite Membranes.
• Used This Improved Understanding To Predict Which Membranes Would Be Effective In Separating a Given Mixture
• Used Molecular Simulation to Explain the Separation Mechanism in Zeolite Membranes.
• Determine The Key Parameters/Properties Of The Membrane That Influence The Separation Efficiency
• Use Molecular Simulations To Model The Transport Of Gases –i.e. Diffusion or Adsorption
• Focus All Design Efforts On These Key Specifications To Improve The Design Of Membranes.
• Use Molecular Simulations As A Quick Screening Tool For Determining The Suitability Of A Membrane For A Proposed New Separation Problem
Zeolite Membrane
y z
x
Feed Compartment (High Pressure)
Feed Compartment (High Pressure)
Product Compartment (Low Pressure)
Recycling Regions
FAU Zeolite MFI Zeolite CHA Zeolite
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Solubility of Gases in Liquids Under Extreme ConditionsInvestigators: Huajun Yuan, Cynthia Jameson and Sohail Murad
Primary Grant Support: National Science Foundation, Dow Chemical Company
• Needs for Better Physical Property Model
• Industrial Interest – Safe Storage of Liquids at Extreme Conditions
• Understand Molecular Basis For Chemical Shift in Liquids
• Explain At the Fundamental Molecular Level the Close Relation Between Chemical Shift and Solute-Solvent Interaction Potential
• Use This Information to Develop Strategies For Better Design of Solute-Solvent Interaction Potentials, and Provide a Better Estimation of Henry’s Constant (Solubility of Gases in Liquids)
• Determined the Key Parameters of Solute-Solvent Interaction Potential, Improved the Potential for Better Solubility Estimations.
• Calculated the Gas Solubility of Xenon in Different Alkanes at Different Temperatures. Showed that Improved Agreement with Chemical Shift Resulted In Better Solubility Results
• Able to Use Modified Potential Model to Get Better Estimations of Solubility of Gases In Liquids, Especially under Extreme Conditions Which are Difficult to Measure Experimentally.
• Use Molecular Dynamics Simulation to Model Chemical Shift of Gases in Alkanes
• Determine the Key Parameters of Solute-Solvent Interaction Potential.which Affect the Solubility
• Use Molecular Simulation for Chemical Shift Calculation as a Quick Screening Tool for Improving the Intermolecular Potential.
• Estimate the Solubility of Gases in Liquids using the Improved Potential Model.
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Rheology of Polymeric and Complex Nanostructured FluidsInvestigator: Ludwig C. Nitsche, Chemical Engineering Department
Collaborator: Lewis E. Wedgewood, Chemical Engineering Department
• Derive macroscopic constitutive laws from stylized molecular models of polymers and complex fluid substructure in dilute solution.
• Obtain probability density functions describing external (translational) and internal (conformational) degrees of freedom of suspended bead-spring entities.
• Manipulate complex fluids with flow geometry and external fields.
• Developed model of cross-stream migration of polymers in flows with gradients in shear.
• The first asymptotic PDF for the classic problem of FENE dumbbells stretching in elongational flows.
• Rigorous basis for the recent “L-closure”, and analytical explanation for the numerically observed collapse of transient stress-birefringence curves for different polymer lengths.
• Numerical simulations by atomistic smoothed particle hydrodynamics (ASPH).
• “Smart swarms” of particles solve the Smoluchowski equation for translational and conformational motions of dumbbell models of polymers in dilute solution.
• Asymptotic theory (singular perturbations and multiple scales) consolidates numerics and extracts formulas for probability density profiles, scaling laws and rheological constitutive equations.
Numerical versus asymptotic PDF’s for a linear-locked dumbbell
Closure relations for the conformatioally averaged Smoluchowski equation
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
A Simple, Scientific Way to Optimize Catalyst PreparationJohn R. Regalbuto, Dept. of Chemical Engineering
Prime Grant Support: NSF
• supported metal catalysts like the automobile catalytic converter are immensely important for
• environmental cleanup • chemical and pharmaceutical synthesis• energy production
• catalyst preparation is thought of as a “black art”
• industry has successful recipes but little fundamental understanding; development is laborious and expensive
• our lab is a world leader at fundamental studies of catalyst preparation
• fuel cell electrocatalysts
• automobile catalytic converters
• petroleum refining catalysts
method of “strong electrostatic adsorption:”
• locate pH of optimal electrostatic interaction
• reduce metal coordination complex at conditions which retain the high dispersion of the precursor
• extremely small nanocrystals result (sub-nanometer)
• metal utilization is optimized
• method is generalizeable
OH2+
O-
pH<PZC
pH>PZC
OHPZC
K1
K2
[PtCl6]-2
[(NH3)4Pt]+2
[H]+ (pH shifts)
Kads
Kads
OH2+
O-
pH<PZC
pH>PZC
OHOHPZC
K1
K2
[PtCl6]-2
[(NH3)4Pt]+2
[H]+ (pH shifts)
Kads
Kads
0
0.2
0.4
0.6
0.8
1
0 2 4 6 8 10 12 14pH Final
Pt a
dsor
bed
(m
ol/m
2) L90
M7D
EH5
VN3S
FK300
Model
1) Electrostatic adsorption mechanism
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Problem Statement and Motivation
Key Achievements and Future GoalsTechnical Approach
Non-Newtonian Fluid Mechanics: The Vorticity DecompositionLewis E. Wedgewood, Chemical Engeineering Department
Prime Grant Support: National Science Foundation, 3M Company
• Construct a Theory that Allows the Vorticity to be Divided into an Objective and a Non-Objective Portion
• Develop Robust Equations for the Mechanical Properties (Constitutive Equations) of Non-Newtonian Fluids using the Objective Portion of the Vorticity
• Solve Flow Problems of Complex Fluids in Complex Flows such as Blood Flow, Ink Jets, Polymer Coatings, Etc.
• Improved Understanding Of the Modeling of Complex Fluids
• Applications to Structured Fluids such as Polymer Melts, Ferromagnetic Fluids, Liquid Crystals, etc.
• Development Of Constitutive Relations Suitable For Design Of New Applications
• Verification Of Hindered Rotation Theory And The Transport Of Angular Momentum In Complex Fluids
• Mathematical Construction of Co-rotating Frames (see Figure above) to Give a Evolution for the Deformational Vorticity (Objective Portion)
• Finite Difference Solution to Tangential Flow in an Eccentric Cylinder Device
• Brownian Dynamics Simulations of Polymer Flow and Relation Between Polymer Dynamics and Constitutive Equations
• Continuum Theory And Hindered Rotation Models To Model Mechanical Behavior