For in-situ TEM measurement in liquid environment, the TEM sample holder is specially designed so that a small chamber can be filled with liquid (sample) and imaged through a SiN3 window that is transparent to the electron beam. Liquid cell TEM is currently the cutting-edge technique to follow self-assembly of nanoparticles, and to visualize nucleation, internal structure evolution, and aging of nanocrystals. The method gives deep and comprehensive insight to each stage of self-assembly and will allow the direct and live visualization of micelle formation, nanoparticle assembly, diffusion, association and lattice formation in dependence of environmental conditions (temperature, pH, salinity, etc.).
Soft matter imaging is currently still challenging. Although examples for the successful imaging of soft matter are increasing, the visualization of organic matter is not straightforward due to low electron contrast compared to the liquid background (50nm-5µm of liquid). Since liquid cell TEM has predominantly been utilized to analyze inorganic nanomaterials, part of our research specifically focuses on concepts to tackle the issue of low contrast and to optimize this method for soft matter analysis. We are convinced that liquid cell TEM has great potential for investigating soft matter self-assemblies.