According to Science China, with the development of nanotechnology and nanomaterials, a variety of functional materials are gradually introduced as additives to enhance specific aspects of performance, such as anti-inflammatory and anti-bacterial, anti-aging, catalytic, etc.
For example, adding a certain amount of nano-silica to rubber can improve the physical and mechanical properties of rubber, enhance its wear resistance, tensile and tear strength and hardness, and play a reinforcing role. Adding a small amount of layered hydrotalcite nanomaterials to plastics and rubber can improve the performance of flame retardant and anti-UV oxidation.
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Nowadays, more and more lifestyle products are labeled with advanced nanomaterials to enhance product performance and even develop unprecedented new functions. So are these products using nanomaterials really as advertised? Are nanomaterials really that god?
Today, let's talk about nanomaterials.
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What is Nano?
First of all, what is nano? Actually it is a unit of length, 1 nanometer (nm) is equal to 1 billionth of 1 meter, which is roughly equivalent to the length of 10 hydrogen atoms arranged together. It is generally believed that a material with a dimensional size of less than 100 nm in three-dimensional space can be called a nanomaterial. The processes and methods involved in the preparation, processing and application of nanomaterials are collectively referred to as nanotechnology. Since the first discovery of the nanoscopic world by scanning tunneling microscopy in the 1980s, nanotechnology and nanomaterials have developed rapidly in the following decades and have emerged in various fields.
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When the material size reaches the nanometer scale, it usually has properties that the bulk material does not have. This is mainly because the surface atoms of nanomaterials are very active and more reactive, and the presence of quantum size effect makes them have special physical and chemical properties, including optical properties, electrical conductivity, catalytic activity, and antibacterial properties.
Take gold as an example, the ordinary nugget material is a golden yellow solid, with good electrical conductivity and ductility. And when it turns into nanomaterial, it can be stably dispersed in the solvent to form a sol, and present different colors according to the size and shape of gold nanomaterials.
Among them, gold nanomaterials with infrared or near-infrared light absorption can also be used for photothermal treatment of cancer. As carbon materials with better biocompatibility, they have significantly improved electrical and thermal conductivity when they are transformed from conventional carbon materials to monolayer graphene.
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Nano Products in Life
So the products that we see in life mixed with nanomaterials, can they also have such magical effects? Is the content of nanomaterials in products high? In fact, for nanomaterials, the root of their special properties is their nanoscale size. Due to their large specific surface and active nature, nanomaterials are not easy to be stably dispersed and thus tend to agglomerate and lose their original properties when preparing composites. It is a difficult process to prepare products that fully retain the properties of nanomaterials.
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At the same time, the manufacturing cost of nanomaterials is high, and it is difficult to prepare functional products entirely using nanomaterials. For example, graphene underwear with various functions such as sterilization and sweat absorption. Although graphene is also a carbon material, its preparation process is demanding and difficult to mass produce, and the value of each gram of graphene product is about 1000 yuan. To completely use graphene to manufacture a pair of underwear, the cost is conservatively estimated to be tens of thousands of dollars.
But we buy products that are just a hundred or so, or even a few dozen dollars, indicating that the content of nanomaterials in the product is certainly not very high. In addition to the above-mentioned exaggerated propaganda, there are also some belong to the "nothing".
For example, the nano kit, which claims to "balance yin and yang, dredge the meridians, and play a healthy role in all aspects of the body", mentions in the publicity that the nano fabric is close to the human skin and can rely on the strong catalytic decomposition to break down the garbage on the walls of the blood vessels and expel it from the body through metabolism. Such products are obviously fictional and exaggerate their functions, even if the nano materials have certain efficacy, it is not possible to replace the existing medical means.
Despite the exaggerated claims of these lifestyle products, nanotechnology and nanomaterials do play an increasing role in the military, science and technology, and other fields.
For example, the superhydrophobic material designed based on the bionic structure of lotus leaf surface is water, oil and dust resistant, which is important in precision equipment and surface cleaning. And ordinary daily necessities with the word "nano", we do not have to worship too much, according to the normal commodity treatment is good.
In the future, we hope that through further development of nanotechnology, nanomaterials will be truly used in ordinary household products to enhance user experience.
