限制在纳米孔中的离子液晶中的相位过渡和动态
Hiroki Nobori1, Daisuke Fujimoto1, Jun Yoshioka1
1Department of Physics, Ritsumeikan University, Noji-Higashi 1-1-1, Kusatsu 525-8577, Japan.
The Journal of chemical physics
|January 23, 2024
概括
纳米孔中的限制会改变离子液晶相变. 在较小的毛孔内,质阶段变得更加稳定,影响它们的行为和动态.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 离子液晶表现出复杂的相位行为.
- 限制效应可以显著改变材料的特性.
- 了解这些变化对于设计先进材料至关重要.
研究的目的:
- 为了研究1 - 甲基-3 - 基利米达四甲酸 ([Cnmim]BF4) 离子液晶在圆柱状纳米孔中限制的相变行为.
- 为了阐明孔径大小和基链长度对相位过渡和动态的影响.
- 为了探索不同阶段的热力学稳定性在限制下.
主要方法:
- 差分扫描热量计 (DSC) 用于热分析.
- 用于结构特征的X射线散射.
- 介电放松光谱 (DRS) 对于动态性质.
主要成果:
- 纳米孔的限制导致相位过渡温度的改变,通常随着孔径的反向而下降.
- 在冷却过程中观察到一个转移稳定的阶段,在加热后通过晶体阶段过渡到异型.
- 与散装相比,涂抹阶段在纳米孔中显示了增强的热力学稳定性.
- 玻璃过渡温度取决于孔径和基链长度,表明链的动态发生了变化.
结论:
- 纳米孔中的限制显著影响[Cnmim]BF4离子液晶的相位行为和动态.
- 状阶段可以由于被限制而变得热力学稳定,这种现象在批量中没有观察到.
- 基链动态显然受到孔隙封闭的影响,这对材料设计有影响.
相关概念视频
Molecular and Ionic Solids
17.1K
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
17.1K
Ionic Crystal Structures
14.3K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
14.3K
Crystal Field Theory - Octahedral Complexes
26.5K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
26.5K


