Create Nanosheets in One Minute

A new technology for making nanosheets, which are thin films of 2D material several nanometers thick, in about one minute was developed by a study team led by Professor Minoru Osada (he, he) and postdoctoral researcher Yue Shi (he, he) at Institute of Materials and Systems for Sustainability (IMASS), Nagoya University in Japan.

This technology facilitates the development of large, high-quality nanosheet films with just one click without the need for special technology or knowledge. Their results are believed to add to the development of industrial manufacturing processes for various types of nanosheet devices. ACS Applied Materials & Interfaces publish this research.

Nanosheet comes with a thickness that is measured in nanometers. Nanometers are so thin that they are invisible from the side to the naked eye. They can be used in a variety of areas, in addition to catalysis, electronics, biomedicine and energy storage. Those made from inorganic and graphene nanosheets are subject to tests for applications in various devices, from sensors and batteries to solar cells, because they have the functions of transparency, electricity and heat resistance, unlike traditional bulk materials.

However, the techniques used to make these thin films, such as the Langmuir-Blodgett approach, require complex conditions and skilled operations.

Using the existing method, it will take about an hour to make one layer. This creates a major bottleneck in nanosheet manufacturing.

Professor Minoru Osada, Institute of Materials and Systems for Sustainability, University of Nagoya

The team is aiming to develop a new method that can make high-quality monolayer films of neatly stacked nanosheets smoothly and quickly. By applying a drop of aqueous colloid solution to a substrate heated on a hot plate with an automatic pipette, they set up an automated film forming process that produces nanosheets in about one minute. Furthermore, they follow this with the aim of dissolution and fluid removal. The result is a neatly tiled monolayer film with no gaps between the nanosheets.

“The reduction of the surface tension of colloidal aqueous solutions and promotion of convection of the nanosheets suppressed the overlap and gaps between the nanosheets and allowed us to control their alignment. Layer-by-layer construction of multilayer films controlled by unit thickness of nanosheets is made possible by repeating the fabrication operation of neatly stacked monolayer films..”

This newly developed method is expected to become an important technology as an industrial thin-film fabrication method and a nanocoating method for nanosheets because it is simple, fast, and requires only a small amount of solution to manufacture high-quality, large-size products. film areas with neat tile alignment.

Professor Minoru Osada, Institute of Materials and Systems for Sustainability, University of Nagoya

Dare to continue.”This technology is based on a simple drip and aspiration operation using an automatic pipette and does not require special knowledge or technology. This technology is applicable to nanosheets of various compositions and structures, such as oxide, graphene and boron nitride, and can form films on substrates of various shapes, sizes and materials, making it a very versatile film forming technology..”

Journal Reference:

Shi, Y., et al. (2023). Automatic One-Drop Assembly for Smooth 2D Film Deposition. ACS Applied Materials & Interfaces. doi.org/10.1021/acsami.3c02250.

Source: https://en.nagoya-u.ac.jp/