使用小角度X射线散射和原子力显微镜来确定AOT + 有机的微结构
B A Simmons1, C E Taylor, F A Landis
1Contribution from the Department of Chemical Engineering, Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, USA.
Journal of the American Chemical Society
|July 18, 2001
概括
阳离子表面活性剂 bis(2-乙) 硫酸盐 (AOT) 与非极性溶剂中的p-类一起形成有机凝. 这些凝呈现出独特的纤维捆结构,由AFM和SAXS可视化.
科学领域:
- 超分子化学 超分子化学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 器官凝是可以在固体网络中封装液体的材料.
- 表面活性剂是可以在溶液中自组装成各种结构的分子.
- 了解表面活性剂的自我组装对于设计新型材料至关重要.
研究的目的:
- 为了研究由 bis ((2-乙烯) 硫酸盐 (AOT) 和p-醇形成的有机凝的形成和微观结构.
- 阐明非极性溶剂在自组装过程中的作用.
- 为了描述由此产生的有机凝的分子结构.
主要方法:
- 在各种非极性溶剂中使用AOT和p-chlorofenol形成有机凝.
- 用于结构分析的小角度X射线散射 (SAXS).
- 触摸模式原子力显微镜 (AFM) 用于直接可视化.
主要成果:
- 在,和等溶剂中,有机凝以1:1的AOT:摩尔比率自发形成.
- 萨克斯数据揭示了AOT/链的溶剂依赖的特性长度尺度,这些AOT/链可以自组装成纤维.
- AFM成像证实了有机凝结构包括聚合纤维束.
结论:
- 机体凝结构基于与结合的AOT/链形成纤维,然后聚合成捆.
- 提出了一个分层的分子架构,有三个不同的长度尺度 (链,纤维,捆).
- 溶剂的化学性质显著影响自我组装和由此产生的凝特性.
相关概念视频
X-ray Diffraction of Biological Samples
X-ray diffraction or XRD is an analytical tool that utilizes X-rays to study ordered structures such as crystalline organic and inorganic samples, polycrystalline materials, proteins, carbohydrates, and drugs.
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
Atomic Force Microscopy
Atomic force microscopy (AFM) is a type of scanning probe microscopy that can analyze topographic details of various specimens like ceramics, glass, polymers, and biological samples. AFM offers over 1000 times more resolution than the optical imaging system. Images generated from AFM are three-dimensional surface profiles, offering an advantage over the flat, two-dimensional images from other imaging techniques.
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
The AFM Probe
The probe is regarded as the heart of any AFM setup and comprises the...
Electron Microscope Tomography and Single-particle Reconstruction
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Overview of Microscopy Techniques
The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes that leveraged nonvisible light, such as fluorescence microscopy that uses an ultraviolet light source and electron microscopy that uses short-wavelength electron beams. These advances significantly improved magnification, image resolution, and contrast. By comparison, the...
Atomic Absorption Spectroscopy: Atomization Methods
Atomic Absorption Spectroscopy (AAS) atomizes samples through flame atomization or electrothermal atomization. Flame atomization typically involves a nebulizer and spray chamber assembly to combine the sample with a fuel–oxidant mixture, creating a fine aerosol mist that enters a burner. Typically, the fuel and oxidant are combined in an approximately stoichiometric ratio. However, for atoms that are easily oxidized, a fuel-rich mixture may be more advantageous. Only about 5% of the aerosol...
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 are...


