反直觉的趋势是入压力与温度在疏水体 Cu2(tebpz) MOF
Sebastiano Merchiori1, Andrea Le Donne1, Ribhu Bhatia1
1Department of Chemical, Pharmaceutical and Agricultural Sciences, University of Ferrara, Ferrara, 44121, Italy.
Small (Weinheim an der Bergstrasse, Germany)
|August 8, 2024
概括
在疏水性MOF中,水的入压力表现出异常的温度依赖性. 增加的蒸汽压力起到值作用,在更高的温度下取代水性变化,这与预测相反.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 纳米技术纳米技术
背景情况:
- 疏水性金属有机框架 (MOF) 对于分离和储存至关重要.
- 了解纳米孔中的液体侵入是MOF应用的关键.
- 现有的模型,如扬-拉普拉斯定律,可能无法完全捕捉亚纳米尺度现象.
研究的目的:
- 在疏水性MOF中研究温度依赖的水入压.
- 澄清观察到的异常压力趋势背后的潜在机制.
- 确定孔隙疏水性,蒸汽压力和入侵动态之间的相互作用.
主要方法:
- 液体孔径实验测量入压力.
- 分子动力学模拟用于模拟流体行为.
- 测试孔状特征的同步子实验.
主要成果:
- 观察到水入压力与温度的特殊趋势,偏离了扬-拉普拉斯预测.
- 在更高的温度下,确定了MOF孔内的蒸汽密度的增加,从而产生了显著的部分压力值 (≈5 MPa).
- 发现在升高的温度下,降低的疏水性和表面张力效应变得占主导地位,扭转了压力趋势.
结论:
- 这项研究阐明了一种复杂的温度驱动机制,该机制控制了水MOF纳米孔中的水的入.
- 毛孔内的蒸汽压力积累起到关键的作用,在更高的温度下作为入侵的关键障碍.
- 这一发现挑战了简单的疏水性驱动模型,并强调了考虑纳米孔材料蒸汽相行为的重要性.
更多相关视频
07:32Pool-Boiling Heat-Transfer Enhancement on Cylindrical Surfaces with Hybrid Wettable Patterns
Published on: April 10, 2017
9.0K
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
1.9K
相关概念视频
Le Chatelier's Principle: Changing Temperature
29.5K
Consistent with the law of mass action, an equilibrium stressed by a change in concentration will shift to re-establish equilibrium without any change in the value of the equilibrium constant, K. When an equilibrium shifts in response to a temperature change, however, it is re-established with a different relative composition that exhibits a different value for the equilibrium constant.
To understand this phenomenon, consider the elementary reaction:
To understand this phenomenon, consider the elementary reaction:
29.5K
Clausius-Clapeyron Equation
56.5K
The equilibrium between a liquid and its vapor depends on the temperature of the system; a rise in temperature causes a corresponding rise in the vapor pressure of its liquid. The Clausius-Clapeyron equation gives the quantitative relation between a substance’s vapor pressure (P) and its temperature (T); it predicts the rate at which vapor pressure increases per unit increase in temperature.
56.5K
Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
44.2K
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
44.2K
Phase Diagrams
40.4K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
40.4K
Phase Diagram
5.8K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
5.8K
