What is plasma?
Plasma is an ionized gaseous substance consisting of positive and negative ions produced by the ionization of atoms and groups of atoms after partial deprivation of electrons and is considered to be the fourth form of matter in addition to solids, liquids, and gases, which is externally electrically neutral.
The device that generates the plasma is the plasma generator.
• The main working principle of the plasma generator is to raise the low voltage through a booster circuit to positive and negative high voltage, using the positive and negative high voltage to ionize the air (mainly oxygen) to produce a large number of positive and negative ions, the number of negative ions is greater than the number of positive ions (the number of negative ions is about 1.5 times the number of positive ions).
• The plasma generator simultaneously generates positive ions and negative ions in the air to neutralize the positive and negative charges at the same time generating a huge release of energy, which leads to a change in the structure of the bacteria around it or conversion of energy, thus causing the bacteria to die and achieving its sterilizing effect. As the number of negative ions is greater than the number of positive ions, the excess negative ions still floating in the air can achieve the health effects of smoke elimination, dust removal, odor elimination, and improvement of air quality to promote human health.
The principle of anion sterilization and air purification
First of all, what we need to understand is: sterilization is sterilization, and air purification is air purification. These are two completely different concepts.
Sterilization refers to the adoption of some measures to hinder the growth and reproduction of bacteria within the scope of the measures, or even die.
Air purification refers to the removal of unnecessary impurities within the scope of the measures through some measures so that the air in the range of space can reach a certain degree of cleanliness.
1、Sterilization mechanism of negative ions
The negative ions (negative oxygen ions) in the air come into contact with bacteria, molds, viruses, etc., because the negative ions themselves carry excess electrons, which will destroy their molecular protein structure, resulting in structural changes (protein polarity reversal) or energy transfer, resulting in the death of bacteria, viruses and other microorganisms. However, an appropriate concentration of negative ions is not only harmless to the human body, but also beneficial to human health (as detailed below), so "negative ion sterilization" is a more environmentally friendly way of sterilization than ozone or ultraviolet sterilization.
2、Purification mechanism of negative oxygen ions.
Negative ions, as a kind of charged particles, their purification principle is actually like the common phenomenon in our daily life, that is, rubbing rubber sticks with fur can absorb small confetti, or using plastic combs to comb hair will absorb hair, and so on. It is realized by using electrification to attract light and small objects.
In other words, air negative ions can make particles invisible to the naked eye (as small as 0.01 microns) and floating dust and odor molecules in the air to form neutral molecular clusters and sink to the ground by attracting, colliding, and neutralizing each other between positive and negative ions. To achieve the effect of dust reduction, deodorization, and purification.
Some experiments have proved that when the concentration of negative ions in indoor air reaches 20000 per cubic centimeter, the amount of particulate dust in the air will be reduced by more than 98%!
In addition, negative ions can also play a certain role in cleaning up indoor decoration pollution. Because negative ions have the characteristics of small particle size and high activity, the diffusion of gas can quickly spread to every corner of the room, and actively combine with air pollutants, such as formaldehyde, toluene, TVOC, and other decoration pollutants, and decompose them into non-toxic carbon dioxide and water, which can alleviate the decoration pollution residue to a certain extent. To a certain extent, it is because the release of volatile pollutants such as formaldehyde is a slow process for many years, and it will continue to be produced along with the removal, so the newly renovated house must be supplemented by frequent window ventilation to accelerate the volatilization of formaldehyde.
In summary, it can be seen that in theory, negative ions do have a certain sterilization and purification effect. And its sterilization method is more environmentally friendly and safer for the human body. Its purification effect is also extremely simple and natural. More importantly, it is also very effective in removing TVOC. For example, it can decompose formaldehyde and benzene into carbon dioxide and water, which is safe and environmentally friendly. It plays a good role in purifying the air.
However, it should be noted that the "removal" of small particles by negative ions only sinks them and falls on the surface or the ground, not completely removed. Therefore, it is necessary to wipe the ground and the surface of the object.
Plasma Treatments Can Quickly Kill Coronavirus on Surfaces
From the Journal: Physics of Fluids
Link to article: Cold atmospheric plasma for SARS-CoV-2 inactivation
Zhitong Chen, Gustavo Garcia, Vaithilingaraja Arumugaswami, Richard Edward Wirz
University of California, Los Angeles
At this special period, we need to consider all aspects of life and work to protect our health, so a plasma sterilizer/purifier is a good choice.
WASHINGTON, November 10, 2020 — Researchers from UCLA believe that using plasma could promise a significant breakthrough in the fight against the spread of COVID-19.
In Physics of Fluids, published by AIP, modeling conducted in June showed strains of the novel coronavirus on surfaces such as metal, leather, and plastic could be killed in just 30 seconds after being treated with cold atmospheric plasma injected with argon.
A schematic of UCLA’s cold atmospheric plasma device with an image of it in operation. CREDIT: Wirz Research Group, UCLA
The researchers used an atmospheric pressure plasma jet which was built with a 3D printer to spray surfaces that were treated with SARS-CoV-2 cultures. The surfaces included plastic, metal, cardboard, and basketball, football, and baseball leather.
The spray using plasma fed by argon killed all the coronavirus on the six surfaces in less than three minutes, and most of the virus was destroyed after 30 seconds. Additional testing showed the virus was destroyed in similar times on cotton from face masks.
This kind of novel coronavirus can remain contagious for hours on the surface. . Author Richard E. Wirz said the findings show great potential for the use of plasma in halting the virus’s transmission cycle.
“This is just the beginning,” Wirz said. “We are very confident and have very high expectations for plasma in future work. In the future, a lot of answers for the scientific community will come from plasma.”
Plasma is one of the four basic states of matter, which can be produced by heating neutral gas or placing it in a strong electromagnetic field. As a relatively new technology, cold atmospheric plasma is an ionized, near-room temperature gas that has been proved to be effective in cancer treatment, wound healing, dentistry, and other medical applications.
The authors ran a similar coronavirus test with helium-fed plasma, but the helium was not effective, even with treatments up to five minutes. The authors believe this was due to lower rates of reactive oxygen and reactive nitrogen when using helium-fed gas, compared to argon.
Zhitong Chen said the authors are building a compact device that could be used widely to treat coronavirus surfaces with plasma. He says this is a safer and healthier option than chemicals or other treatments.
“Everything we use comes from the air,” he said. “Air and electricity: It’s a very healthy treatment with no side effects.”
The researchers hope that the benefits of plasma, as shown in this study, will be made available to people around the world.