接触冷水滴的水晶有机酸的接触冷
Zachary R Schiffman1,2,3, Kyle A McMillan1,2, Dharma M Johnson1,2
1Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, Colorado 80309, United States.
The journal of physical chemistry. A
|August 4, 2025
概括
某些有机固体作为冰核粒子 (INP),在比纯水更高的温度下促进水滴中的冰形成. 这一发现对于理解大气冰核形成过程至关重要.
科学领域:
- 大气化学 大气化学
- 云物理 云物理
- 材料科学 材料科学 材料科学
背景情况:
- 混合相云中的冰晶形成显著影响云的特性和降水量.
- 接触结,即与粒子接触时发生冰核形成,是关键的,但不太了解的冰核形成途径.
- 大气中的气溶,包括有机化合物,可以作为冰核粒子 (INPs).
研究的目的:
- 在接触冷模式下研究各种大气相关有机酸的冰核化能力.
- 确定在更高温度下可以作为有效的冰核粒子 (INP) 的特定有机固体.
- 确定与接触模式下冰核化效率提高相关的物理和化学特性.
主要方法:
- 利用配备拉曼显微镜的环境室研究冰核形成.
- 暴露的水滴与十一种不同的有机化合物的固体晶体.
- 测量了这些有机固体诱导接触结的温度.
主要成果:
- 在11种被测试的有机固体中,有10种 (多可桑醇,酸,酸,酸,4-基酸,棕酸,酸,脂酸,酸,酸,酸和香草酸) 在明显高于纯水的温度下 (-15.0~-18.5°C vs. -21.3°C) 促进接触冷.
- 酸是唯一一种在较高温度下不促进接触冷的化合物.
- 在接触模式下INP的有效性与水晶格子与冰的不匹配,碳数和水中的不溶性相关.
结论:
- 有关大气的有机固体可以在接触冷模式下作为强大的冰核粒子 (INPs).
- 这些有机固体可以在比原先预期的纯水温度更高的温度下促进冰核形成.
- 这些发现表明,有机气溶在大气冰核形成中起着重要作用,影响云的特性和气候.
相关概念视频
Crystal Growth: Principles of Crystallization
2.6K
Crystallization is a phase transformation process in which crystals are precipitated from a supersaturated solution or formed from other sources. During crystallization, atoms or molecules arrange themselves into a well-defined, rigid crystal lattice to minimize energy.
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
2.6K
Freezing Point Depression and Boiling Point Elevation
35.8K
Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
35.8K
Recrystallization: Solid–Solution Equilibria
1.2K
Recrystallization is a purification technique used to separate impurities from solid compounds. In this technique, no chemical reactions occur. Instead, it exploits physical properties only, specifically, the solubility differences between the desired compound and impurities, either at a single temperature or at different temperatures, and under other selected conditions. The solid-solution equilibrium (solubility equilibrium) of each component in the solution represents a binary phase...
1.2K
Colloidal precipitates
759
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
759
Types of Coprecipitation
874
Coprecipitation is the contamination of a precipitate by otherwise soluble species and occurs via different processes. In colloidal precipitates, coprecipitation occurs via surface adsorption. For instance, barium sulfate has a primary layer of adsorbed barium ions and a secondary layer of nitrate counterions. This results in contamination of the precipitate by barium nitrate.
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...
874
States of Water
53.6K
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
53.6K


