Institute for Pure and Applied Mathematics, UCLA
Navigating Chemical Compound Space for Materials and Bio Design
Workshop III: Materials Design in Chemical Compound Space
May 2 - 6, 2011
Towards Materials Ageing
A Case Study in Navigating Energy Landscapes
Sidney Yip
Nuclear Science and Engineering/Materials Science and Engineering
MIT
Connecting a few dots …
energy landscape view of time evolution of atomic system
An algorithm (metadynamics) to sample transition state pathway
Use TSP trajectories to explain the viscosity of glasses
-- the nature of fragility in the glass transition
Other problems of slow dynamics (materials ageing) where atomistic
simulations can elucidate the molecular mechanisms
Energy Landscape Perspective
Transition State Pathway Sampling (ABC)
TSP trajectories → Q(T)
Calculate viscosity of supercooled liquids
Connection with other materials ageing phenomena
Cement setting
corrosion
creep
viscosity
Viscosities of vitrified liquids are in need of explanation by atomistic simulation
C. A. Angell, J. Phys. Chem. Solids 49 (1988)
A metadynamics algorithm : Autonomous Basin Climbing
A. Kushima et al, J Chem Phys 130 (2009)
Viscosity of a binary LJ model (Kob) calculated
using a coarse-graining formulation based on TSP trajectory
 (T )   0 exp[ Q(T ) / k BT ]
A. Kushima et al, J Chem Phys 130 (2009)
TSP trajectory analysis to obtain an effective temp-dep activation barrier Q(T)
A. Kushima et al, J. Chem. Phys.130 (2009)
Green-Kubo calculation using Network Model and TSP trajectories
A. Kushima et al, J. Chem. Phys.130 (2009), J. Li, Plos ONE 6, e17909 (2011)
Green-Kubo calculation using Network Model and TSP trajectories
MD
Experimental test of predicted viscosity of SiO2
SiO
Potential: Feuston 2and Garofalini, JCP (1988)
Saika-Voivid et al, Nature (2001)
Horbach and Kob, Phys.Rev. B (1999)
C. A. Angell, J Phys Chem Solids 88 (1988)
A. Kushima et al, J. Chem. Phys.131 (2009)
Disconnectivity Graphs of a fragile and strong glass former
A. Kushima, JCP 131 (2009)
See Becker and Karplus, JCP 106 (1977), D. Wales (2006)
Potential energy landscape profiles (derived from TSP trajectories)
A. Kushima et al., JCP 131 (2009)
F. H. Stillinger, JCP 88 (1988)
Explanation of the signature behavior of glass transition
-- revealing the underlying energy landscape that gives rise to the
fragile temperature scaling of the shear viscosity η(T)
Mystery (mechanism) of the dynamical crossover
(physical nature of fragility)
Transition from strong to fragile behavior with decreasing T
signals the onset of deep local energy minima
giving rise to the sharp increase of Q(T)
contributors
Akihiro Kushima (MIT/UPenn)
Xi Lin (BU)
Ju Li (UPenn/MIT)
John Mauro (Corning Research Center)
Jacob Eapen (NCSU)
Xiaofeng Qian (MIT)
Phong Diep (Corning Research Center)
That was Stop 1
Continuing onto Creep, Corrosion, and Cement,
which is Stop 2 (end of navigation)
Creep deformation in steel P-91
MD strain rates ~ 107 s-1
!
R. L.Klueh, Int. Mat. Rev. 50, 287 (2005)
Stress corrosion cracking
C. Ciccotti, J. Phys. D 42 (2009)
J. W. Martin, BP Research (2010)
DOE Energy Innovation Hub in Nuclear Modeling and Simulation
CASL: Consortium for Advanced Simulation
of Light Water Reactors
Core partners
Oak Ridge
National Laboratory
Electric Power
Research Institute
Idaho National Laboratory
Los Alamos National Laboratory
Massachusetts Institute
of Technology
North Carolina State University
Sandia National Laboratories
Tennessee Valley Authority
University of Michigan
Westinghouse Electric Company
Awarded May 28,
2010
Vision: Create a predictive simulation capability
for a virtual LWR
Chalk River Unidentified Deposits (CRUD)
CRUD deposition/growth (early stage) and CRUD-induced
localized corrosion (late stage) leading to clad cracking
Fe++
Ni++
Cement hydration (setting) is a ‘grand challenge’ to molecular simulation
percolation/
jamming
Shear
modulus
G* [Pa]
C-S-H precipitation
gelation
C3S + H2O → C-S-H + Ca(OH)2
C3S = Ca3SiO3
C-S-H = CaO-SiO2-H2O
Ultrason measurement, w/c = 0.8 [Lootens 2004]
green = inter-layer Ca
• grey = intra-layer Ca
• blue = oxygen
• white = hydrogen
•
(CaO)1.65(SiO2)(H20)1.75
Binary Colloidal Model with sticky potentials [P. Monasterio, 2010]
Model is undergoing further
development to incorporate
C-S-H nucleation/growth
Energy Landscape Perspective
Transition State Pathway Sampling (ABC)
TSP trajectories → Q(T)
Calculate viscosity of supercooled liquids
Connection with other materials ageing phenomena
Cement setting
corrosion
creep
viscosity
Energy Landscape Perspective
TSP trajectory
ABC
viscosity
Energy Landscape Perspective
TSP trajectory
ABC
Cement setting
corrosion
creep
viscosity
Energy Landscape Perspective
TSP trajectory
ABC
processes relevant to materials ageing
Cement setting
corrosion
creep
viscosity