The preparation of frozen amorphous nano-meter thin films of solutions containing particles, and imaging with energy filtered TEM, opens for the first time the possibility to map the elemental distribution in solids interacting with liquids. The future possible areas of research in solution include: dynamic of crystal growth processes, adsorption mechanisms, ion exchange, structure determination of nano-sized solids in equilibrium with different solvents, etc.
The sample preparation uses a controlled-environment vitrification system. Solidification of the liquid phase was achieved by plunging the solution, suspended in the holes of a lacy carbon on a copper grid, into liquid ethane (-174 °C). The specimen was transferred into the microscope by an Oxford CT3500 cryo-holder. The specimen temperature in the microscope column can be kept at -183 °C. The thickness of the vitrified film's, including the particles, should be about 50-100 nm or preferably less. The Philips CM120 BioTWIN Cryo microscope, here used for cryo-EFTEM, has a focal length of 6 nun and a structural resolution of 0.4 nm.