11. Phase Diagram of an Au–Pt Solid Core–Liquid Shell Nanoparticle
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Nadi Braidy
Abstract
Binary equilibrium phase diagrams are ubiquitous tools for predicting the behavior of multiphase systems. For a binary mixture with fixed global composition and temperature, a equilibrium phase diagram predicts the number and type of phases in equilibrium, and their respective fraction and composition. Equilibrium phase diagrams are computed from empirical thermodynamic properties of the existing phases and solutions. The calculations does not take into account energy terms that may arise because of surface, interface, strain, etc. With the emergence of nanoparticles (NPs) research, several attempts were made to compute binary nano-phase diagram. These studies consider only the energy term of the outer surface, which scales with the inverse of the radius of the NP. However, three important factors are typically omitted from the calculations: first, the shape and the energy of the solid-solid or solid-liquid interface; second, a mass balance constraint that can limit the phase composition of a nanoparticle and third the relative stability of a single, supersatured phase against a two-phase NP system. In this Chapter, we compute the nano-phase diagram of a binary mixture of Au and Pt, with a solid core-liquid shell configuration by incorporating these three principles. We demonstrate that the liquidus and solidus phase boundaries of an Au-Pt nano-phase diagram for a two-phase core-shell configuration is restricted to a much smaller compositional range than the phase composition. Of note, we show that the stability of the two-phase region shrinks significantly with decreasing size, even for NPs as large as 100 nm in diameter, and disappears below ~41.5 nm, where the NP no longer sustains an interface.
Abstract
Binary equilibrium phase diagrams are ubiquitous tools for predicting the behavior of multiphase systems. For a binary mixture with fixed global composition and temperature, a equilibrium phase diagram predicts the number and type of phases in equilibrium, and their respective fraction and composition. Equilibrium phase diagrams are computed from empirical thermodynamic properties of the existing phases and solutions. The calculations does not take into account energy terms that may arise because of surface, interface, strain, etc. With the emergence of nanoparticles (NPs) research, several attempts were made to compute binary nano-phase diagram. These studies consider only the energy term of the outer surface, which scales with the inverse of the radius of the NP. However, three important factors are typically omitted from the calculations: first, the shape and the energy of the solid-solid or solid-liquid interface; second, a mass balance constraint that can limit the phase composition of a nanoparticle and third the relative stability of a single, supersatured phase against a two-phase NP system. In this Chapter, we compute the nano-phase diagram of a binary mixture of Au and Pt, with a solid core-liquid shell configuration by incorporating these three principles. We demonstrate that the liquidus and solidus phase boundaries of an Au-Pt nano-phase diagram for a two-phase core-shell configuration is restricted to a much smaller compositional range than the phase composition. Of note, we show that the stability of the two-phase region shrinks significantly with decreasing size, even for NPs as large as 100 nm in diameter, and disappears below ~41.5 nm, where the NP no longer sustains an interface.
Chapters in this book
- Frontmatter I
- Preface V
- Contents IX
- List of Contributors XI
- 1. Design Principles for Organic Semiconductors 1
- 2. CO2-Controlled Polymer Self-Assembly and Application 51
- 3. Self-Healing Materials: Design and Applications 87
- 4. Redox-Responsive Self-Assembled Amphiphilic Materials: Review and Application to Biological Systems 113
- 5. Ultrafine Nanofiber Formation by Centrifugal Spinning 143
- 6. Rational Design of Highly Efficient Non-precious Metal Catalysts for Oxygen Reduction in Fuel Cells and Metal–Air Batteries 161
- 7. Toward the Assembly of Dynamic and Complex DNA Nanostructures 183
- 8. Alternating Copolymer Nanotubes 209
- 9. Molecular Glasses: Emerging Materials for the Next Generation 239
- 10. Production of Pluripotent Stem Cell-Derived Pancreatic Cells by Manipulating Cell-Surface Interactions 261
- 11. Phase Diagram of an Au–Pt Solid Core–Liquid Shell Nanoparticle 285
- 12. Directing the Self-Assembly of Nanoparticles for Advanced Materials 307
- 13. Toward Well-Defined Carbon Nanotubes and Graphene Nanoribbons 327
- 14. Modeling of Lithium-Ion Batteries 353
- Index 389
Chapters in this book
- Frontmatter I
- Preface V
- Contents IX
- List of Contributors XI
- 1. Design Principles for Organic Semiconductors 1
- 2. CO2-Controlled Polymer Self-Assembly and Application 51
- 3. Self-Healing Materials: Design and Applications 87
- 4. Redox-Responsive Self-Assembled Amphiphilic Materials: Review and Application to Biological Systems 113
- 5. Ultrafine Nanofiber Formation by Centrifugal Spinning 143
- 6. Rational Design of Highly Efficient Non-precious Metal Catalysts for Oxygen Reduction in Fuel Cells and Metal–Air Batteries 161
- 7. Toward the Assembly of Dynamic and Complex DNA Nanostructures 183
- 8. Alternating Copolymer Nanotubes 209
- 9. Molecular Glasses: Emerging Materials for the Next Generation 239
- 10. Production of Pluripotent Stem Cell-Derived Pancreatic Cells by Manipulating Cell-Surface Interactions 261
- 11. Phase Diagram of an Au–Pt Solid Core–Liquid Shell Nanoparticle 285
- 12. Directing the Self-Assembly of Nanoparticles for Advanced Materials 307
- 13. Toward Well-Defined Carbon Nanotubes and Graphene Nanoribbons 327
- 14. Modeling of Lithium-Ion Batteries 353
- Index 389
