Air positive and negative ions can be divided into large, medium and small ions according to their mobility. What is beneficial to the human body are small ions, also called light ions, which have good biological activity. Only small ions or small ion clusters can enter the organism.
The moving speed of ions under the action of an electric field of unit strength (V/m) is called ion mobility, which is an important parameter to distinguish the diameter of the measured ion. The smaller the diameter of air ions, the faster their migration speed. Ion mobility is an important parameter to express the size of the measured ion. The ion movement speed is inversely proportional to the ion diameter, and the ion mobility is directly proportional to the ion movement speed, so the ion mobility is negatively proportional to the ion diameter.
Air positive and negative ions can be divided into large, medium and small ions according to their mobility. Ion mobility greater than 0.4c㎡/(V`s) is a small ion, less than 0.04/(V`s) is a large ion, and between the two is a medium ion. Charged atomic groups or molecular groups that are close to the molecular size are all small air ions. These small air ions have a high speed of movement, collide with each other in the atmosphere, and continue to gather to form large or medium ions.
How negative ions are produced

Negative ions use the pulse oscillation circuit of the negative ion generator to boost the low voltage to DC negative high voltage through the high voltage module. The negative DC high corona is continuously generated through the tip of the carbon fiber, and a large number of electrons (e-) are emitted at a high speed. Electrons cannot exist in the air for a long time (the life of electrons in the air is only ns level), and they will be captured by oxygen molecules (O2) in the air immediately to form negative ions. Its working principle is the same as the natural phenomenon of "thunder and lightning". The phenomenon of negative ions is the same.
Negative ions are everywhere in nature. Natural phenomena such as thunder and lightning, plant photosynthesis, and waterfall water impact can all produce a large amount of negative ions. This is why people feel fresh air in thunderstorms, forests, and waterfalls.

The role of negative ions

(1) Fresh air, smoke and dust removal: negatively charged negative ions and positively charged smoke and dust floating in the air are neutralized by electrodes to make them naturally deposited.
(2) Negative ions can enhance the moisture retention of hair. Normally, the hair surface is in the form of scattered fish scales. Negative ions can regain the scattered fish scales on the surface of the hair so that the hair looks more shiny, and at the same time it can neutralize the hair. The static electricity that exists between prevents the hair from splitting ends.

application:

At present, there are many products on the market that claim to use negative ions, such as: electric fans, air purifiers, air conditioners, hair dryers, hair straighteners, electric splints, electric combs, monitors, computer cases, desk lamps, energy-saving lamps, night lights, Humidifiers and other products.
However, it should be noted that long-term continuous use of negative ions can cause headaches, asthma, low immunity and other problems. Therefore, the amount and proportion of negative ions should be controlled when using negative ions.

Precautions:
Negative ions are colorless and odorless, and there should be no ozone smell (similar to seaweed smell and fishy smell) at 30 cm. Ozone is a strong oxidant that can age cells and is a healthy killer. Some irresponsible businesses will interpret the taste of ozone as the taste of negative ions. The national standard of ozone is 0.5ppm (as long as it smells, it has exceeded the standard). A good negative ion machine will not produce ozone smell no matter how long it is turned on in a closed room.