An Investigation of Boron Nitride Nanomaterial Functionalization

At the Army Research Laboratory

by Kevin Waters

Who am I?

  • Computational "Physicist"
  • Started at Michigan Tech. in 2013
  • Working with Ravindra Pandey
  • Currently at PNNL on a Fellowship
  • Defending in August

Hypothesis

"We can accurately predict the interface between biological molecule and nanomaterials in physiological conditions."

Nanomaterials

Materials with at least one dimension in the sub-micron range.

Nanomaterials

  • Ratio of surface to bulk atoms changes
  • Bulk properties are not present at this scale
  • Adding one atom changes the properties of the material
  • Exhaustive searches and research must be done

Morphological Dependent Properties

  • Clusters
  • Nanoparticles
  • Fullerenes
  • Nanotubes
  • 2D-Materials
  • A. K. Geim et. al Nature Materials (2007) 6: 183
  • Boron Nitride Nanotubes

    • Predicted by 1994
    • Synthesized in 1995
    • Typically considred a wide band gap semiconductor
    • Parameters to consider
      • Chirality (n,n), (n,0), (n,m)
      • Diameter
      • Layers

    Boron Nitride Nanotubes

  • Steel, "A Primer on Carbon Nanotubes – Part 1"
  • Boron Nitride Nanotubes (Band Gap)

    Boron Nitride Nanotubes (Strain Energy)

    Rimola et. al. (2013) PCCP 15:13190

    Biological Molecules

    • Carbohydrates
    • DNA (Nucleotides)
    • Lipids
    • Proteins (Amino Acids, Peptides)
    • etc.

    Methods and Tools

    • Solving the system's electronic wavefunction
      • Schrödinger Equation
      • Density Functional Theory (DFT)
      • Ab Initio Molecular Dynamics (AIMD)
      • High Performance Computing Platform

    Conjugated Boron Nitride Nanomaterials

    Waters et. al. (2017) ACS Omega 2:76

    Proteins

    pdb : 3V03
    Waters et. al. (2017) ACS Omega 2:76

    Conjugated Structures

    Binding Energies

    Binding Energies

    BNML (eV)
    Pro. Dep.
    Trp -1.04
    Arg -0.92 -0.96
    Asp -0.55 -0.57
    BNNT
    Pro. Dep.
    Trp -0.71
    Arg -0.85 -2.12
    Asp -0.89 -2.17

    Mechanical Properties of 2D BN2

    Waters et. al. (2018) Journal of Physics: Condensed Matter 30: 13

    Chemical Functionalization

    Experimental Functionalization


    Sainsbury et. al. (2007) JACS 111:12992

    BN Electronic Structure Evolution

    Coverage (%) Band Gap (eV) Binding Energy (eV)
    0 4.25
    16 3.34 -0.74
    25 3.11 -0.70
    50 2.25 0.72

    BN2 Monolayer

    • Atoms 2B + 4N
    • Symmetry : Amm2 (38)
    • Lattice Vectors
      • a : 6.84
      • b : 2.55
    • Bonds
      • N-N : 1.29
      • B-N : 1.50
      • N-B : 1.34

    BN2 Band Structure (Orbital Projected)

    BN2 Band Structure (Atom Projected)

    Hooke's Law / Elastic Tensor


    • σij is the stress tensor
    • Cijkl is the elastic tensor
    • εkl is the stain tensor

    Elastic Tensor

    Orthorhombic Symmetry (Amm2)

    Orthorhombic Symmetry in 2D

    Deformation Matrices

    Workflow

    • -2% to 2% in steps of 0.2%
    • Generate optimized structure
    • Apply deformation matrix to optimized structure
    • Optimized atoms with modified unit cell
    • Extract Cauchy stress data (σij)
    • Calculate mechanical properties of interest

    Properties Derived from Elastic Constants

    Results


    N/m Graphene1 This Work BN2 This Work BN2
    C11 358.1 353.7 293.2 290.5 368.8
    C12 60.4 61.7 66.1 64.4 47.2
    C22 153.3
    C66 144.9 113.1 58.7

    Mechanical Properties of Crystalline Poly Ether Ether Ketone (PEEK)

    Pisani et. al. (2018) In Prepartation

    US-COMP

    • The Institute for Ultra-Strong Composites by Computational Design
    • NASA Space Technology Research Institute
    • Computationally-driven development of CNT-based ultra high strength lightweight structural materials
    • Project lead by Dr. Odegard at Michigan Tech.

    PEEK

    • Polyether ether ketone
    • Investigating properties of the polymer future applications
    • ReaxxFF force field testing and validation
    • Comparing crystalline classical MD with DFT calculations
    • Challenging to model Amorphous PEEK with electron approach

    PEEK Structure

    • O12C48H78
    • Symmetry : Pbcn (60)
    • Lattice Vectors
      • a : 7.38
      • b : 5.92
      • c : 30.09



    Orthorhombic Symmetry (Pbcn)

    PEEK Elastic Constants

    Elastic Constants

    (GPa) MD DFT
    C11 140.5 ± 7.31 133.3
    C22 4.87 ± 1.56 15.5
    C33 7.18 ± 1.34 24
    C44 0.24 ± 0.16 14.0
    C55 3.79 ± 3.00 9.0
    C66 3.37 ± 0.36 4.8

    Poisson's Ratio

    MD DFT
    ν12 0.88 ± 0.24 0.38
    ν13 -0.01 ± 0.58 -0.33
    ν23 0.50 ± 0.12 0.38

    Gold Deposition Boron Nitride Nanomaterials

    Waters et. al. (2018) In Prepartation

    Gold Quantum Dots on Boron Nitride

    Boron Nitride Nanotubes Functionalized with Gold Quantum Dots

    Gold Flakes on Boron Nitride

    Gold Flakes on Boron Nitride

    Unpublished work from Bhandari et. al.

    Gold Cluster Structures

    2D 3D
  • Unpublished work from Waters et. al.
  • L. Xiao et al. (2004) Chemical Physics Letters 392, 452
  • L. Xiao et al. (2006) The Journal of Chemical Physics 114309
  • G. Chen et. al. (2010) The Journal of Chemical Physics 194306
  • Gold Clusters Structural Parameters

    2D Cluster
    Structure Avg. Bond (Å) Bonds (#) Symmetry
    Au6 2.69 9 D3h
    Au10 2.71 19 D2h
    Au12 2.71 24 D3h
    Au14 2.71 29 D2h
    Au16 2.72 34 Cs
    3D Cluster
    Structure Avg. Bond (Å) Bonds (#) Symmetry
    Au6 2.73 10 Cs
    Au10 2.72 23 C2v
    Au12 2.75 26 C2v
    Au14 2.74 33 Cs
    Au16 2.73 36 Td

    Gold Cluster Cohesive Energy

    Gold Clusters on BN

    Gold/BN Clusters Parameters

    2D Cluster
    Structure Avg. Bond (Å) Bonds (#) Symmetry
    Au6 2.69 (2.70) 9 (9) D3h (D3h)
    Au10 2.71 (2.72) 19 (19) D2h (D2h)
    Au12 2.71 (2.72) 24 (24) D3h (D3h)
    Au14 2.71 (2.72) 29 (29) D2h (D2h)
    Au16 2.72 (2.72) 34 (34) Cs (Cs)
    3D Cluster
    Structure Avg. Bond (Å) Bonds (#) Symmetry
    Au6 2.73 (2.74) 10 (10) Cs (Cs)
    Au10 2.72 (2.72) 23 (18) C2v (Cs)
    Au12 2.75 (2.76) 26 (24) C2v (C2v)
    Au14 2.74 (2.74) 33 (29) Cs (C1)
    Au16 2.73 (2.72) 36 (32) Td (C1)

    Gold Clusters

    2D Cluster Band Gap (eV)
    Structure Ref 1 Isolated Cluster/BN
    Au6 2.06 1.76 (2.76) 1.73
    Au10 1.28 0.96 (1.47) 0.81
    Au12 0.97 0.65 (1.47) 0.63
    Au14 0.19 0.00 (0.35) 0.00
    Au16 0.24 (0.95) 0.18
  • L. Xiao et al. (2004) Chemical Physics Letters 392, 452
  • Gold Clusters

    3D Cluster Band Gap (eV)
    Structure Ref 1,2 Isolated Cluster/BN
    Au6 1.75 1.22 (1.91) 1.53
    Au10 0.91 0.29 (0.72) 0.45
    Au12 0.95 0.92 (1.43) 0.72
    Au14 0.44 0.35 (0.53) 0.18
    Au16 0.24 (0.95) 0.54
  • L. Xiao et al. (2004) Chemical Physics Letters 392, 452
  • L. Xiao et al. (2006) The Journal of Chemical Physics 114309
  • Gold Cluster Electronic Gap

    Conjugated Gold Cluster Electronic Gap

    Current/Future Work

    • Improve accuracy for the exact exchange integral in PBC (NWChem)
    • AIMD studies on the peptide/BNNTs interface in a solvated environment
    • Test plane-wave AIMD simulations with O(N) DFT methods

    Challenges

    • Computation power (Hardware/Software)
    • Scaling of theories (CCSD vs. DFT vs. MD)
    • Choosing the "right" theory
    • Inclusion of all releveant paramters (ions, solution, pH)
    • Asking the right questions

    Conclusion

    • Layed the foundation for protein BNNT simulations
    • Started to investigate functionalized structurs
    • Building framework for future large scale applications
    • Flexibility to look a similar structures (e.g. Polymers)

    Acknowledgements

    • Ravindra Pandey
    • Eric Bylasksa
    • Gregory Odegard
    • Nabanita Saikia
    • Max Seel
    • Wil Slough
    • Yoke Khin Yap

    Questions