The silk! That expensive and elegant fabric that all of us were passionate about for the simple fact that to obtain it it was enough to raise a lot of worms adorable.
It is a beautiful and vaporous material, used especially in the textile industry, although it also has other different applications, such as the manufacture of suture not absorbable by the body. In fact, its range of uses could be much larger if it were not for the fact that it is a quite fragile material, as can be seen in the labels of the size of a bible that usually accompany garments made with it, advising of all the care that must be taken when washing and ironing it.
Therefore, one of the great objectives of scientists is to obtain modified silks with properties among which stands out a greater resistance, which would make it possible to add a large number of new uses. And as the experts on the subject have never ceased to be the worms, a team of researchers from the Tsinghua University has carried out a study in which they add carbon and graphene nanotubes to food of these weavers, managing to incorporate it into silk and bring it a great number of new characteristics.
A curious method to obtain more resistant silk
Years ago scientists have tried to modify silk through the substance addition such as pigments, antimicrobial agents, or electrically conductive polymers, but it is usually a complicated process that must be performed in the laboratory and is difficult to carry out. big scale.
Therefore, bearing in mind that silk fibers are obtained from proteins manufactured in the salivary glands of certain worms, which many of us have raised as children, a team of scientists, who published their results in Nano Letters, decided to resume an experiment that had already been carried out in the past, consisting of adding the desired substances to the mulberry leaves from which these animals feed.
To do this, they manufactured a solution with a 02% by weight of carbon and graphene nanotubes, which was sprayed on the leaves that will be ingested by the worms before making their cocoons, which were collected in the same way as is done to obtain the traditional silk.
More resistant silk, but with many questions to solve
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After analyzing the silk obtained from cocoons, it was found that, as expected, the material obtained was twice as resistant than the conventional one, being able to support a 50% more stress before breaking.
Furthermore, it also turned out to be a good conductor of electricity and have a crystal structure much more orderly.
So far, all is good news, but those responsible for the study warn that it is still necessary to answer many questions, such as the reason why these ingested additives go to silk and, above all, what proportion of them finally remains in the tissue, without being discarded by the animal.
This is an important factor, since its complete understanding can help optimize the process, administering to the animal only the amounts necessary for the silk modification.
Regarding the reason why the results of this study have been better than those of other similar previous studies, these researchers assure that the key lies in the carbon tube sizebecause in the past they had been used 30 nanometers in diameterwhile yours 1-2 nanometers, have shown that the smaller they are, the better they will be incorporated into silk.
If everything is on track, this project could lead to strong and conductive silk fibers, which could be used in the elaboration of smart fabrics, biodegradable medical implants and environmentally friendly electronic devices. It certainly sounds good, so we’ll be waiting for the results.