Does graphene really resist lung disease caused by epidemic?

Graphene and graphene oxide are very expensive experimental raw materials, which are difficult to be used for mass-produced civil products, let alone consumables. The so-called "graphene" that causes lung symptoms is not real graphene, and it is more likely to be just activated carbon.

Sun Yafei

Tsinghua University, Ph.D. in Chemistry.

Graphene has been the darling of materials science for nearly ten years. In the past two years, with the spread of the epidemic, some epidemic prevention products began to claim to use graphene as raw materials, which made a lot of profits in the market.

Interestingly, graphene, which once had infinite scenery, also suffered from Waterloo. There are many rumors on the Internet that graphene masks and graphene cotton swabs can cause lung diseases, and some people have sorted out various crimes of graphene oxide (GO, a derivative of graphene), which is an attitude of settling accounts after autumn. From the content, graphene oxide seems to have been used as a biochemical weapon.

Legend: Regarding the content of graphene, graphene oxide seems to have been used as a biochemical weapon.

From the perspective of materials science, these statements can be said to be full of loopholes. For example, GO may be activated by 5G frequency, which is actually nonsense. Because graphene oxide is not an organic substance or a molecule with life function, it naturally has no biological activity or no activity. Even in the list, there are some contradictory statements in itself. Go, for example, will produce a metallic taste in the mouth, but later it will lead to the loss of taste and smell. Obviously, this is just a joke written by some boring people, satirizing the practice of applying the concept of graphene or graphene oxide to various fields at will, but some people take these incredible statements seriously.

In fact, we can understand how ridiculous these statements are as long as we think about this problem in reverse. If GO is a chemical weapon and has so many bizarre functions, is it necessary for poisoners to process it into cotton swabs, masks and even make great efforts to add it to vaccines? Wouldn't it be easier to throw it directly into the food? Anyway, let's talk about the relationship between graphene and the COVID-19 epidemic.

1. What is graphene and how did it catch fire?

I believe that after so many years of publicity, many people are familiar with the term graphene, which is essentially single-layer graphite.

Graphite is a crystal structure formed by carbon element, which is very common in life. For example, pencil lead is mainly composed of graphite and clay. The more graphite, the softer the refill, but the darker the words written. The reason why graphite can write is mainly because it has a flaky structure and the layers are easily dislocated. When it rubs on paper, it will leave a mark.

Each piece of graphite is only as thick as a single atom. Because its chemical properties are similar to those of olefins, it has the title of graphene. This means that even if the thickness of graphite is only one millimeter, it is composed of millions of layers of graphene.

Single-layer graphene is unstable and easy to cluster together, so for a long time, no one believes that it can really be obtained.

In 2004, Andre Geim, a scientist at the University of Manchester in England, came up with a strange and simple method. Graphene materials were obtained for the first time by putting graphite between two layers of adhesive tapes and tearing the adhesive tapes to make the graphite thinner and thinner. With this invention, he won the 20 10 Nobel Prize in Physics.

As soon as graphene came out, it attracted the attention of materials scientists because of its excellent properties. For example, it retains the good conductivity of graphite, but because it is only as thick as a single atom, it is extremely outstanding in superconductivity. While studying at MIT, Cao Yuan, a talented scientist in China, took graphene as the research object, deeply discussed the internal principle of superconductivity, and published several top journals in succession, which shocked the world.

However, pure graphene is difficult to apply because it has no active chemical groups. Therefore, the general practice is to treat graphene with concentrated acid to make it into graphene oxide, so that it can interact with other substances.

Despite this, graphene and graphene oxide have not been able to go to civilian products because they are too expensive, and civilian products usually do not need their special properties. As for the so-called graphene products on the market, they are basically from false propaganda.

Second, what is the "graphene" in epidemic prevention supplies?

The cause of the incident was actually Health Canada's warning [1].

In April, 20021year, Health Canada said that some people had symptoms in their lungs after wearing a mask, which was as uncomfortable as sucking cat hair. These masks all have a common feature, that is, the words graphene are marked on the packaging. Studies have found that these "graphene particles" will be inhaled by the lungs.

I believe that many people will find two doubts when they see this: why should graphene be made into powder and put in a mask? Which mask manufacturer is so local, can use graphene as a mask?

In fact, these questions are not difficult to answer, as long as you find the original documents of Canada.

Among these materials, the following suddenly appeared:

Translated, these masks were produced by a company in Shandong, China, and nominally contained "biomass graphene". Unexpectedly, it has become a product we export abroad, which is somewhat unexpected.

This is obviously more than that, because we still have to ask, how did a company in Shandong produce a graphene mask?

In the official website of this company, it is not difficult to find the related introduction about the biomass graphene. This material was originally made of straw, but the black powder in the product picture seems unusual.

Legend: Product pictures on enterprise official website.

If we continue to search the patented technology of this company, we can easily find the production process of this biomass graphene, but it is similar.

Just watch the process carefully and people will be curious. Is graphene or nano-scale activated carbon produced? As we all know, activated carbon is also a simple substance of carbon, which is essentially graphite that has failed to form crystals and has a porous structure. Compared with graphene, which is difficult to prepare, the preparation of activated carbon is not difficult.

Further inquiry found that as early as 20 15, this patent was still in doubt. To sum up, the team involved in the invention admits that this technology is not mature [2].

Finally, there is a doubt that graphene has excellent properties, but these properties are mainly in electromagnetism and mechanics. Not an antibacterial expert, activated carbon with high adsorption is.

Improper naming and immature preparation technology all point to the same conclusion that graphene here is essentially finer activated carbon. The so-called "graphene mask" is an own goal, so it is no wonder that Health Canada will investigate the above results. Activated carbon masks are not uncommon in China, and there is indeed a risk of inhaling particulate matter when worn for a long time. Therefore, the simplest non-woven mask is more suitable for epidemic prevention.

In a word, graphene and graphene oxide are very expensive experimental raw materials, which are difficult to be used in mass-produced civil products, let alone consumables. The so-called "graphene" that causes lung symptoms is not real graphene, but more likely activated carbon.