在液-蒸汽界面上,的表面积累和酸平衡
Clemens Richter1, Rémi Dupuy2, Florian Trinter1
1Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany. bluhm@fhi-berlin.mpg.de.
Physical chemistry chemical physics : PCCP
|August 27, 2024
概括
研究醇的研究.
科学领域:
- 物理化学 物理化学
- 表面科学是一门学科.
- 解决方案化学 解决方案化学
背景情况:
- 的表面活性物质在各种化学过程中至关重要.
- 了解和酸在空气-水界面上的行为是必不可少的.
- 之前的研究还没有完全阐明整个pH依赖物种的吸附行为.
研究的目的:
- 为了确定基布斯吸附的自由能量和和酸盐的表面过量.
- 通过使用表面敏感技术,研究散装pKa (9.99) 的吸附行为.
- 为了比较纯/酸盐溶液的吸附性能与pKa.的吸附性能.
主要方法:
- 液体喷射光电子光谱 (LJ-PES) 用于表面分析.
- 用于热力学评估的表面张力测量.
- 改变pH值和散装度以研究-酸的物种化.
主要成果:
- 对于纯/酸盐溶液,LJ-PES与表面张力之间在吉布斯自由吸附能量中的极佳一致性.
- 在散装pKa时,LJ-PES揭示了比酸盐的表面丰富,这与散装预期相反.
- 与纯溶液相比,和酸盐在散装pKa时的吉布斯自由吸附能量的偏差.
结论:
- 和酸盐表现出不同的表面倾向.
- 和酸盐之间的合作相互作用可能会影响近表面成分.
- 表面特异性不同于pKa的散装特异性,影响吸附热力学.
相关概念视频
Acidity and Basicity of Alcohols and Phenols
18.7K
Like water, alcohols are weak acids and bases. This is attributed to the polarization of the O–H bond making the hydrogen partially positive. Moreover, the electron pairs on the oxygen atom of alcohol make it both basic and nucleophilic. Protonation of an alcohol converts hydroxide, a poor leaving group, into water—a good one. The two acid–base equilibria corresponding to ethanol are depicted below.
18.7K
Physical Properties of Alcohols and Phenols
14.1K
Alcohols are organic compounds in which a hydroxy group is attached to a saturated carbon. Phenols are a class of alcohols containing a hydroxy group attached to an aromatic ring. The physical properties of the alcohols and phenols are influenced by hydrogen bonding due to the oxygen–hydrogen dipole in the hydroxy functional group and dispersion forces between alkyl or aryl regions of alcohol and phenol molecules.
Alcohols possess a higher boiling point than aliphatic hydrocarbons of...
Alcohols possess a higher boiling point than aliphatic hydrocarbons of...
14.1K
Distillation: Vapor–Liquid Equilibria
2.7K
Distillation is a separation technique that takes advantage of the boiling point properties of disparate elements in a mixture. To perform distillation, we begin by heating a miscible mixture of two liquids with a significant difference in boiling points (at least 20°C). As the solution heats up and reaches the bubble point of the more volatile component, some molecules of the more volatile component transition into the gas phase and travel upward into the condenser, which is a glass tube...
2.7K
Phase Diagrams
40.3K
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...
40.3K
Vapor Pressure Lowering
26.3K
The equilibrium vapor pressure of a liquid is the pressure exerted by its gaseous phase when vaporization and condensation are occurring at equal rates:
Dissolving a nonvolatile substance in volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be explained by considering the effect of added solute molecules on the liquid's vaporization and condensation processes. To vaporize, solvent molecules must be present at the surface of the solution....
Dissolving a nonvolatile substance in volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be explained by considering the effect of added solute molecules on the liquid's vaporization and condensation processes. To vaporize, solvent molecules must be present at the surface of the solution....
26.3K
Vapor Pressure
34.7K
When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules move randomly about, they will occasionally collide with the surface of the condensed phase, and in some cases, these collisions will result in the molecules re-entering the condensed phase. The change from the gas phase to the liquid is called condensation. When the rate of condensation becomes equal to the rate of vaporization, neither the amount of the liquid nor the amount of the vapor...
34.7K


