在C60表面上的聚合及其对储存的影响
Qiang Sun1, Qian Wang, Puru Jena
1Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
Journal of the American Chemical Society
|October 20, 2005
概括
过渡金属原子如 (Ti) 可以增强碳纳米结构中的储存. 然而,Ti原子倾向于聚集在富勒烯表面上,对储能能力和热力学产生负面影响.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术 纳米技术
- 物理化学 物理化学
背景情况:
- 碳纳米结构由于其高重力密度,对储存具有前景.
- 纯碳材料表现出较弱的键,限制了储存能力.
- 用隔离过渡金属 (Sc,Ti) 涂层纳米结构预测可以增强结合和容量.
研究的目的:
- 为了研究 (Ti) 原子在C60富勒烯表面的行为,用于储存应用.
- 为了确定Ti原子是否在烯表面保持孤立或聚集.
- 评估原子聚合对储能性能的影响.
主要方法:
- 基于密度函数理论 (DFT) 的第一原则计算.
- 在C60表面上模拟Ti原子相互作用.
- 对结能量的分析,热力学和动力学.
主要成果:
- (Ti) 原子倾向于在C60富勒烯表面聚合.
- 聚类显著改变了分子的结合能量.
- 原子的聚合会对储能能力和热力学/运动性质产生负面影响.
结论:
- 对于增强存储的孤立过渡金属原子的假设受到Ti原子聚类的挑战.
- 在C60表面上聚合会降低其作为储存材料的有效性.
- 需要进一步的研究来理解和控制金属原子聚合,以在纳米结构材料中进行最佳的储存.
相关概念视频
Cohesion
Cohesion is the attraction between molecules of the same type, such as water molecules. Water molecules have an overall neutral charge but are polar molecule. An oxygen atom in one water molecule has a partial negative charge that can bind to a hydrogen atom with a partial positive charge in a second water molecule, forming a hydrogen bond. Each water molecule can form up to four hydrogen bonds with other water molecules. Hydrogen bonds are responsible for water's cohesive nature.
On a surface,...
On a surface,...
Chair Conformation of Cyclohexane
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
Stability of Substituted Cyclohexanes
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Stability of Conjugated Dienes
Introduction
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
Complexation Equilibria: Factors Influencing Stability of Complexes
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...


