Ion screening effect of graphene oxide thin film

Wuhengan, a professor at the University of Science and Technology of China, has worked with Nobel Prize winner Andelie·haimu, a professor at the University of Manchester in the United Kingdom, to discover that graphene oxide films have the properties of precision and rapid ion screening. The results were recently published in the journal Science.

According to the report, graphene surface was originally rejected water, but after immersion in the water, the capillary channel in the graphene film allowed rapid water penetration. The researchers found that the graphene oxide film in the water environment interacts with water to form a capillary channel of about 0.9 nm wide, allowing ions or molecules less than 0.9 nm in diameter to pass quickly, while ions larger than 0.9 nm in diameter are completely blocked. This screening effect not only requires very accurate ion size, but also spreads thousands of times faster than the traditional concentration.

Using theoretical analysis and molecular simulation, Wuhengan studied the mechanism of graphene nanoscale fast ion filtration. Computer simulation studies have shown that the interaction between graphene and ions causes ions to aggregate in nanoscale channels, which promotes the rapid diffusion of ions. This discovery gives a reasonable explanation for the experimental results, also known as the "ion sponge effect."

Experts say further mechanical compression of the capillary channels in the films would efficiently filter salt from the water. This means making a filter that can dilute a glass of seawater into drinking water in a matter of minutes is no longer a science fiction scenario.

It is reported that during the same period, the "Science" magazine specifically reviewed the study and believed that the discovery made graphene oxide thin films have important significance in many separation applications. For example, it has broad application prospects in the fields of seawater desalination and purification, sensing technology and energy conversion.

The page contains the contents of the machine translation.