American scientists successfully made nano-scale polyethylene thin film

Washington, DC — Researchers from Konstanz University have developed a new process for making ultra-thin films that is of great significance to scientists and engineers.

A team led by Stefan Mecking from Konstanz University has developed a new process for preparing extremely thin layers.

According to SpecialChem, they prepared the film by pretreating the nanocrystalline structure alone.

The traditional process for preparing an ultra-thin film (thickness less than 0.1 μm) is to dissolve the polymer in an organic solvent to form a dilute solution and apply it to the surface.

In order to destroy the solid polymer crystal structure and dissolve it in the solution at the beginning, the process is often carried out at a high temperature. The regular crystal layer is formed only after the solvent is removed or cooled.

In the new process, researchers used polyethylene (PE), a polymer that has a simple chemical structure and is widely used in fields ranging from films and packaging materials to technical parts.

PE is non-toxic and environmentally friendly - but it is very difficult to generate ultra-thin films.

Polymerization of ethylene with a nickel complex as a catalyst gives a liquid-phase suspension of crystalline polymer particles.

These are separate, separated single crystals, and it contains a thin layer of crystal about 25 x 6 nm thick surrounded by an amorphous (amorphous) layer about 1 nm thick.

The presence of an amorphous phase is often present on the surface of polymer crystals. This liquid phase suspension droplet was dropped on the glass slide and rotated at 2000 rotations per minute (rotary coating).

Excess liquid is removed by rotation, leaving a uniform thin film with a thickness of approximately 50 nm.

Although the amorphous phase only occupies a small part of the particle volume, the interaction between them is very strong, which also makes the individual particles firmly in the film.

This study was published in the journal "Applied Chemistry in Germany". Scientists prepared thin films by pretreating nanocrystalline units alone.