Japanese scientists have created a glue with reset and repeat modes
Scientists from Japan have created a completely new type of glue that can be "turned on" and "turned off" on command. The material was tested on dumbbells weighing 40 kg, and it turned out that a small plate of glue is able to hold an object for three days in a row. The study was published in Advanced Functional Materials under the title "Biotechnology-based glue with on-demand reset and Multiple Reuse modes"
When creating glues, researchers balance between two contradictory properties — how well the glue sticks and how easily it falls apart. Obviously, the improvement of one property usually worsens the other. The ideal glue will be one that holds firmly during use, but can be easily removed for adjustment or when the item is no longer needed.
Scientists from the Japanese National Institute of Materials Science have developed an adhesive that can do just that. They focused on caffeic acid, which can form and break cross-links under different wavelengths of light. In addition, catechin groups present in the chemical structure of caffeic acid are usually found in adhesive ("sticking") components secreted by attaching organisms, such as mussels.
Engineers have created a polymer containing caffeic acid. If the glue is shone with ultraviolet light with a wavelength of 365 nanometers, the substance becomes solid and able to hold heavy objects.
When "stickiness" is no longer needed, the film can be exposed to 254 nm UV radiation. Under this light, the substance returns back to a soft state. At the same time, the glue does not leave any traces on the surface and does not lose its adhesive properties, which, in fact, allows it to be reused as new.
The researchers tested the glue on dumbbells. Glued together with the help of the invented glue, two pieces of the plate were able to hold the weight of 40 kg for 72 hours in a row without signs of destruction.
In other tests, scientists used glue to repair cracks on silicon tubes, and then poured water through them under high pressure — no leaks were found. The glue can also be used underwater. In this case, the properties of the substance do not change in any way.
In this case, Japanese researchers were inspired by mussels. And recently we explained how American scientists coped with a similar "sticky" problem by looking at the solution of kirigami, the ancient Japanese art of paper cutting, which uses folding and cutting, as when creating paper snowflakes.
ORIENT news
