相关实验视频

Updated: May 5, 2026

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

Published on: December 20, 2012

液体酸的光学克尔效应通过五秒钟时间分辨率的X射线液相探测

Hosung Ki^1,2, Seungjoo Choi³, Jungmin Kim^1,2

¹Department of Chemistry and KI for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.

Journal of the American Chemical Society

|August 30, 2021

概括

五秒时间解析的X射线液态图 (fs-TRXL) 提供了一种研究超快分子动态的新方法. 这种X射线散射方法揭示了液体中明显的重定向和转移运动,补充了光学克尔效应光谱学.

科学领域:

物理化学
材料科学
化学物理

背景情况:

光学克尔效应 (OKE) 光谱研究液体中的超快分子动力学.
OKE依赖于测量由激光脉冲诱导的依赖时间的双折射.
了解这些动态对于各种化学和物理过程至关重要.

研究的目的:

引入 femtosecond 时间分辨率的X射线液态图 (fs-TRXL) 作为OKE光谱的替代方案.
证明fs-TRXL在解决与OKE反应相关的微观结构运动的能力.
使用X射线散射选择性监测液体中的不同类型的分子运动.

主要方法:

使用X射线溶液散射作为超快动态的探测器.
将fs-TRXL应用于乙二和乙二中的染料溶液.
分析2D散射模式和q空间数据的异构性,以获得结构信息.

主要成果:

fs-TRXL在没有理论建模的情况下选择性地解决了光对齐分子周围的不同分子运动.
非同位素散射信号捕获重定向动态 (释放,定向扩散).
同位素散射信号捕获转换动态 (相互作用诱导的运动).
不同的重定向运动通过特有的散射模式和时间尺度进行区分.
测量到的散射信号与分子动力学模拟非常一致.

结论:

fs-TRXL提供了液体乙酸中OKE反应的详细结构见解.
这种方法可以分离和描述各种分子运动.
fs-TRXL是研究液体超快动态的强大替代品.

更多相关视频

Sub-nanometer Resolution Imaging with Amplitude-modulation Atomic Force Microscopy in Liquid

Sub-nanometer Resolution Imaging with Amplitude-modulation Atomic Force Microscopy in Liquid

Published on: December 20, 2016

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

相关概念视频

UV–Vis Spectroscopy: Beer–Lambert Law

UV–Vis Spectroscopy: Beer–Lambert Law

The Beer-Lambert law describes the relationship between absorbance and concentration, which combines the principles established by scientists Johann Heinrich Lambert and August Beer. Lambert's law states that when light passes through a medium, the loss in intensity is directly proportional to the original intensity and the path length of the light. Beer's law proposed that the transmittance of a solution remains constant if the product of concentration and path length is constant. The modern...

IR and UV–Vis Spectroscopy of Carboxylic Acids

IR and UV–Vis Spectroscopy of Carboxylic Acids

In IR spectroscopy of carboxylic acids, the C=O bond shows a characteristic band between 1710 and 1760 cm⁻¹, and the O–H bond exhibits a broad band between 2500 and 3300 cm⁻¹.
However, the stretching absorptions for the C=O bond vary depending on the structure of carboxylic acids. The C=O bond of the free carboxylic acids shows a higher stretching frequency, 1760 cm−1, while H-bonded carboxylic acids (dimers) exhibit stretching absorptions at a lower frequency,...

UV–Vis Spectrometers

UV–Vis Spectrometers

The absorbance of UV and visible (UV–visible) radiations is measured using a UV–visible spectrophotometer. Deuterium lamps, which emit UV radiation, and tungsten lamps, which produce radiation in the visible region, are used as light sources in UV–visible spectrophotometers. A monochromator or prism is used for diffraction grating, i.e., to split the incoming radiation into different wavelengths. A system of slits is used to focus the desired wavelength on the sample cell.

Atomic Spectroscopy: Absorption, Emission, and Fluorescence

Atomic Spectroscopy: Absorption, Emission, and Fluorescence

Atomic spectroscopy is a vital tool in elemental analysis, both qualitatively and quantitatively. It can be broadly divided into optical spectroscopy, mass spectroscopy, and X-ray spectroscopy methods. The optical spectroscopic methods are atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), and atomic fluorescence spectroscopy (AFS). The first step in all three methods is atomization, where the solid, liquid, or solution-phase samples are converted into gas-phase atoms and...

Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation

Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation

Inductively coupled plasma (ICP) is the common plasma source used in atomic emission spectroscopy (AES), a technique that detects and analyzes various elements in a sample. This method is often called inductively coupled plasma atomic emission spectroscopy (ICP-AES).
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used....

Atomic Fluorescence Spectroscopy

Atomic Fluorescence Spectroscopy

Atomic fluorescence spectroscopy (AFS) is an analytical technique that involves the electronic transitions of atoms in a flame, furnace, or plasma being excited by electromagnetic (EM) radiation. When these atoms absorb energy, they become excited and subsequently release energy as they return to their original state. This emitted light, or "fluorescence," is observed at a right angle to the incident beam. Both absorption and emission processes transpire at distinct wavelengths, which...