New synthetic polymer is light, very hard and kills viruses
A new polymer has unusual properties: it is very stable, lightweight, can be flexible and can kill viruses. It is also easy to produce.
(Image: Das sehr stablie Polymer sieht unscheinbar aus. Hier wird es gerade in eine Petrischale gelegt.)
A team of scientists at the University of Tokyo has developed a synthetic polymer that combines various unusual properties. The polymer is extremely light, very stable when dry, flexible when wet and can be used as a filter to kill viruses.
Hard polymer
The properties of the newly developed material are similar to those of a natural loofah sponge. The polymer has a similar porosity, the structure of which gives the material extreme strength when dry. With a density of just 0.5 g/cmÂł, it achieves a stiffness of eleven gigapascals. This is around four times as strong as conventional polymers.
“One disadvantage of lightweight polymers is their mechanical weakness – they tend to be very soft,” says Yoshimitsu Itoh, professor in the Department of Chemistry and Biotechnology at the University of Tokyo. “But ours has a low density and yet, a stiffness of eleven gigapascals.”
If the material is exposed to moisture, however, it becomes soft. The polymer reacts to the pH value. Depending on the acidity of the liquid, it becomes stiffer or more flexible. The pores of the polymer are large enough to allow liquids to pass through. At the same time, they are so small that viruses and bacteria can be filtered out. These are killed at the same time.
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The production of the polymer is quite straightforward, the scientists write in the study “Electric double-layer synthesis of a spongelike, lightweight reticular membrane”, which has been published in Science. According to the study, pure water and a mixture of resorcinol and aldehyde, to which a voltage is applied, are sufficient. The substances then spontaneously combine to form an ultra-thin membrane with a porous structure. As the substance is similar to lignin, a substance that is a natural component of wood, it is also environmentally friendly. No further production steps are necessary. The membrane can then be processed into a thin film and synthesized in large quantities.
The polymer can be applied to various surfaces of objects, improving their rigidity and durability without significantly increasing their weight. The material can also be used as a filter.
(olb)
