Environmental Liquid Cell Technique for Improved Electron Microscopic Imaging of Soft Matter in Solution

Area of Science:

• Materials Science
• Microscopy Techniques
• Nanotechnology

Background:

• Liquid-phase transmission electron microscopy (LTEM) conventionally uses thin liquid layers (~0.5 μm) between Si3N4 windows.
• Conventional LTEM limits the ability to control the liquid environment and observe dynamic processes effectively.

Purpose of the Study:

• To develop an improved environmental liquid cell (ELC) for LTEM.
• To enable stable liquid layers with controllable thickness for high-resolution imaging.
• To investigate hydration effects on nanomaterials in a liquid environment.

Main Methods:

• A modified ELC design with a 10-μm spacer allowing gas flow.
• Controlled introduction of humid air to create stable liquid layers of varying thickness.
• High-resolution imaging of gold nanoparticles, polystyrene particles, and nanogels.

Main Results:

• Demonstrated controllable liquid thicknesses from 40 ± 8 nm to 340 ± 71 nm.
• Achieved high-resolution edge imaging of gold nanoparticles (0.8 ± 0.06 nm to 1.7 ± 0.8 nm).
• Successfully imaged low-contrast polystyrene particles and studied hydration effects on nanogels.

Conclusions:

• The developed ELC facilitates stable liquid layers for high-resolution LTEM.
• The ELC is suitable for in situ investigations of liquid specimens and dynamic processes.
• This technique enhances the study of hydration effects and low-contrast materials.