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Modeling Surface Stabilization in Nanoclusters and Nanoparticles
Modeling Surface Stabilization in Nanoclusters and Nanoparticles
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211152657
- ISBN
- 9798384456674
- DDC
- 620.11
- 서명/저자
- Modeling Surface Stabilization in Nanoclusters and Nanoparticles
- 발행사항
- [Sl] : University of California, Berkeley, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 95 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-04, Section: B.
- 주기사항
- Advisor: Persson, Kristin.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Berkeley, 2024.
- 초록/해제
- 요약Nanoclusters, with their atomically-precise structures that have metal cores and molecular-like electronic structures, are interesting materials with a broad range of applications in energy and chemical industries. Gold clusters are of specific interest due to their high quantum efficiency, bio-compatibility, catalytic activity and selectivity. Current characterization techniques lack the temporal and spatial resolution required to understand the behavior of nanoclusters in relevant environments, and as such, synthetic efforts to design new nanoclusters largely rely on trial and error. This thesis describes several approaches to better understand the synthesis and stability of nanoclusters using theory and modeling.As with all modeling, there are trade-offs between model complexity and efficiency. In this thesis, nanoclusters and nanoparticles are simulated with appropriate modeling techniques to answer the relevant questions that are posed at different length and time-scales. In the first part of this thesis, density functional theory (DFT) simulations are employed to map the potential energy surfaces of gold nanoclusters stabilized by ligands. Considering ensembles of clusters was very important in this work, and over 10,000 phosphine-stabilized gold clusters were generated with a ligation algorithm and their stabilities as a function of environment were calculated. These simulations give insight into the importance of ligands in determining stable cluster conformations, as well as the impact of cluster size and ligation on electronic structure and bonding. Next, simulations over longer time periods than would be tractable to calculate with DFT are performed, made possible by the development of an interatomic potential for thiolate-protected gold nanoclusters. The interatomic potential is fitted to many examples of DFT calculated nanoclusters and learns the energy-structure relationships that are present in all thiolate-protected gold nanoclusters. The potential is used to perform long (∼0.1µs) simulations of Au25(SR)18, a known nanocluster that is remarkably stable. Interesting mechanisms are uncovered in the simulations which are not yet possible to observe experimentally. Finally, in order to understand the surprising miscibility of the immiscible elements Au and Rh in ultra-small nanoparticles, I developed a continuum model informed by DFT calculations but applicable to any size of nanoparticle that depends on the enthalpy and entropy of mixing as well as surface energies and surface affinities to adsorbate species present in the synthesis conditions. The unusual mixing behavior observed experimentally is in fact due to the nature of the surface environment of the particle. Overall, at any length scale, the conclusion remains the same: the surface environment has a remarkable impact on nanocluster and nanoparticle energetics and behavior, and care must be taken to model them appropriately to achieve the goal of synthesis by design.
- 일반주제명
- Materials science
- 일반주제명
- Engineering
- 일반주제명
- Physical chemistry
- 일반주제명
- Nanotechnology
- 키워드
- Nanoclusters
- 기타저자
- University of California, Berkeley Materials Science & Engineering
- 기본자료저록
- Dissertations Abstracts International. 86-04B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008250123s2024 us c eng d■001000017163355
■00520250211152657
■006m o d
■007cr#unu||||||||
■020 ▼a9798384456674
■035 ▼a(MiAaPQ)AAI31487662
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a620.11
■1001 ▼aMcCandler, Caitlin.
■24510▼aModeling Surface Stabilization in Nanoclusters and Nanoparticles
■260 ▼a[Sl]▼bUniversity of California, Berkeley▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a95 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-04, Section: B.
■500 ▼aAdvisor: Persson, Kristin.
■5021 ▼aThesis (Ph.D.)--University of California, Berkeley, 2024.
■520 ▼aNanoclusters, with their atomically-precise structures that have metal cores and molecular-like electronic structures, are interesting materials with a broad range of applications in energy and chemical industries. Gold clusters are of specific interest due to their high quantum efficiency, bio-compatibility, catalytic activity and selectivity. Current characterization techniques lack the temporal and spatial resolution required to understand the behavior of nanoclusters in relevant environments, and as such, synthetic efforts to design new nanoclusters largely rely on trial and error. This thesis describes several approaches to better understand the synthesis and stability of nanoclusters using theory and modeling.As with all modeling, there are trade-offs between model complexity and efficiency. In this thesis, nanoclusters and nanoparticles are simulated with appropriate modeling techniques to answer the relevant questions that are posed at different length and time-scales. In the first part of this thesis, density functional theory (DFT) simulations are employed to map the potential energy surfaces of gold nanoclusters stabilized by ligands. Considering ensembles of clusters was very important in this work, and over 10,000 phosphine-stabilized gold clusters were generated with a ligation algorithm and their stabilities as a function of environment were calculated. These simulations give insight into the importance of ligands in determining stable cluster conformations, as well as the impact of cluster size and ligation on electronic structure and bonding. Next, simulations over longer time periods than would be tractable to calculate with DFT are performed, made possible by the development of an interatomic potential for thiolate-protected gold nanoclusters. The interatomic potential is fitted to many examples of DFT calculated nanoclusters and learns the energy-structure relationships that are present in all thiolate-protected gold nanoclusters. The potential is used to perform long (∼0.1µs) simulations of Au25(SR)18, a known nanocluster that is remarkably stable. Interesting mechanisms are uncovered in the simulations which are not yet possible to observe experimentally. Finally, in order to understand the surprising miscibility of the immiscible elements Au and Rh in ultra-small nanoparticles, I developed a continuum model informed by DFT calculations but applicable to any size of nanoparticle that depends on the enthalpy and entropy of mixing as well as surface energies and surface affinities to adsorbate species present in the synthesis conditions. The unusual mixing behavior observed experimentally is in fact due to the nature of the surface environment of the particle. Overall, at any length scale, the conclusion remains the same: the surface environment has a remarkable impact on nanocluster and nanoparticle energetics and behavior, and care must be taken to model them appropriately to achieve the goal of synthesis by design.
■590 ▼aSchool code: 0028.
■650 4▼aMaterials science
■650 4▼aEngineering
■650 4▼aPhysical chemistry
■650 4▼aNanotechnology
■653 ▼aNanoclusters
■653 ▼aElectronic structures
■653 ▼aGold nanoclusters
■653 ▼aDensity functional theory
■653 ▼aCatalytic activity
■690 ▼a0794
■690 ▼a0652
■690 ▼a0537
■690 ▼a0494
■71020▼aUniversity of California, Berkeley▼bMaterials Science & Engineering.
■7730 ▼tDissertations Abstracts International▼g86-04B.
■790 ▼a0028
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17163355▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
