A new microscopy technique takes images with atomic resolution of the structure of salts dissolved in water

 A team of researchers from the Higher Council for Scientific Research (CSIC) has developed a new technique of microscopy of forces in three dimensions that allows taking images with atomic resolution of the organization and structure of salts dissolved in water. The results of the study, published in the journal Nature Communications, could be applied in various scientific fields such as materials science, energy, and molecular biology.

“This technique breaks an existing paradigm in force microscopy that establishes that atomic resolution is only obtained on flat surfaces, that is, in two dimensions. The new technique displays atomic resolution images in a three-dimensional volume. This technique has allowed us to observe that in the proximity of a solid surface, common salt is organized with a structure that simultaneously presents the properties of a solid and a liquid. It is the first time that this type of behavior has been observed ”, explains the CSIC researcher Ricardo García, from the Madrid Institute of Materials Science.

The developed method provides images of how the atoms of electrolyte salts dissolved in water such as common salt (sodium chloride) or potassium chloride are arranged in the vicinity of a surface. The images show that in the vicinity of a solid surface and below the saturation concentration, the sodium and chlorine atoms organize themselves with a different structure than their crystalline structure.

“We have been able to observe that common salt is organized with a structure that simultaneously presents properties of a solid and a liquid (the high mobility of ions and water molecules). This technique may have applications in the development of new methods to accumulate energy and in nanomedicine to understand the interaction between drugs and proteins at the molecular level.

The research is funded by the European Science Foundation, 3DNanoMech project, aimed at designing and constructing a high-speed force microscopy method to characterize solid-liquid interfaces with atomic and molecular resolution.