Silver ion is silver in which the silver atom loses more than one electron, which means that silver exists in ionic state and is usually positively charged. Ag+ 1, Ag2+, Ag3+, etc. Silver ion medical products have been listed in China Pharmacopoeia since last century, such as silver nitrate solution. The oxidation activity of silver ions varies with the price, and the oxidation degree of +2 and +3 silver ions is high. The redox potential of Ag+ measured by voltammetry is (0.798 ev, 25℃), while Ag2+ has a higher redox potential (0. 102 ev, 25℃). The effectiveness of high-valent silver ions is 300 to 17000 times that of metallic silver or silver salts. Silver ions with high valence are also called active silver ions because of their high reduction potential.
Therefore, as far as "silver ion" is concerned, it is characterized by:
1. Silver ion is a positively charged "cation", which is formed by electron transfer through chemical reaction;
2. The application of silver ion depends on the nature of the ion and the charged electricity price, and has nothing to do with the size of the ion, so there is no nano effect.
3. Silver ions exist in the form of aqueous solution. Colorless and transparent, without any solid particles;
4. Silver ion drug products have been included in the national pharmacopoeia as early as last century, such as silver nitrate solution.
Antibacterial effect of silver ion
Silver is one of the trace elements in human tissues, and trace silver is harmless to human body. WHO stipulates that the safe value of silver to human body is below 0.05ppm, and the limit of silver ion in drinking water is 0.05 mg/L.
The antibacterial mechanism of silver is metal ions and photocatalysis. Mr. Zhang Wenzheng once said that the chemical structure of silver determines that silver has high catalytic ability, and the reduction potential of highly oxidized silver is extremely high enough to generate atomic oxygen in the surrounding space. Atomic oxygen is highly oxidizing and can kill bacteria. Ag+ can strongly attract sulfhydryl group (-SH) on protease in bacteria, and quickly combine with it, making protease inactive and leading to bacterial death. When the bacteria are killed by Ag+, Ag+ is released from the bacterial carcasses and then comes into contact with other colonies. The above process is repeated, which is also the reason for the persistence of silver sterilization. According to the determination, when the content of Ag+ in water is 0.0 1mg/ 1, Escherichia coli in water can be completely killed, and no new flora is produced within 90 days.
Nano-silver particles can identify the flora well in the sterilization process, maintain the living environment of beneficial flora well, and do no harm to the normal flora, normal cells and human immune system. Therefore, nano-silver will not produce any toxic or irritating reaction to human body.
From ancient times to the present, jade has been regarded as a sacred and auspicious thing from emperors to ordinary people. Apart from being rare and precious, jade is considered to have magical health care effects on human body. Shennong's Classic of Materia Medica, Compendium of Materia Medica and other ancient medical classics all record that jade has the following functions: "removing heat, relieving annoyance, moistening the heart and lungs, helping the voice and throat, nourishing hair, nourishing the five internal organs, calming the heart and calming the nerves, dredging blood vessels and brightening eyes and ears"; It is also recorded: "If you take it for a long time, you will be cold-resistant and heat-resistant, and you will not die if you are not hungry." These propaganda made the emperors and generals eat jade and live forever, which was called "jade food".
According to the theory of "cool head and warm feet" in traditional Chinese medicine, modern clinical medicine has proved that jade pillow has different degrees of curative effect on hypertension, nervous headache and cerebrovascular disease.
The calming, calming and beautifying effects of jade are vividly reflected in the beauty secret method of Empress Dowager Cixi, that is, rubbing, kneading and squeezing the face with a jade stick. Its medical explanation is that cool jade massage can calm facial nerves, shrink facial pores and promote facial blood circulation, and of course the effect will be good.
From the analysis of modern biology, physics, chemical medicine and other fields, the results show that jade itself is the most abundant gas storage material, equivalent to a large magnetic field. Wearing jade ornaments or displaying jade articles indoors often can improve human microcirculation, accelerate metabolism and activate cell tissue, thus enhancing people's immunity and achieving the functions of disease prevention and fitness.
Health care function of silver: silver has bactericidal effect, and food with silver tableware is not easy to ferment and turn sour; Silver compounds can treat burns and bandage wounds;
Silver chopsticks can detect sulfur-containing poisons in food.
No one knows when humans discovered metallic silver, but our ancestors have long known that this metal has magical purification ability: 2,500 years ago, King cyrus the great of Persia ordered all his troops to hold water in silver jars, because the water released by silverware was cleaner than other containers. In ancient Rome, silver nitrate was used as medicine, which was recorded in the Pharmacopoeia of Rome Publishing House in 69 BC. In 78 AD, Pliny Sr described the characteristics of silver in his book Natural History: "It has therapeutic effect ... especially in promoting wound healing."
Rich Romans used silver wine glasses and silverware every day, not only because silver was a symbol of wealth: aristocratic families fed their babies with silver spoons, which they thought would drive away diseases. "At that time, people didn't know the sterilization mechanism of silver," said A.Bart Flick, a plastic surgeon and trauma rehabilitation expert in Clayton, Georgia. Frick often uses silver to treat local wounds. He said: "Obviously, silver is good for people's health, and it was not harmful at that time. Therefore, people regard silver as a "safe metal" "
Today, more than half of the airlines in the world have used silver water filters. The water in swimming pools in many countries is also purified with silver. Unlike chemicals, this purified water will not irritate the swimmer's skin and eyes. Silver stockings produced by a company contain silver-plated fibers, which can inhibit the propagation of fungi and prevent beriberi and foot odor. Another company has developed a warm water washable toilet, which is made of ultra-smooth ceramics and contains silver, which plays an antibacterial role with the slow release of silver ions.
So why is silver antibacterial? Silver is one of the earliest metals used by human beings. Herders in Inner Mongolia grassland have long noticed that horse milk in a silver bowl will not turn sour for a few days. Modern research has further revealed the mystery: silver can kill bacteria. As long as a small amount of silver is dissolved in water and becomes silver ions, it has high bactericidal ability. Scientists have done experiments. Twenty-three liters of sewage (containing more than 7,000 Escherichia coli per milliliter) were treated with silver electrode for three hours, and all the Escherichia coli died. A few parts per billion of silver can make a liter of water clean. According to the experiment, typhoid bacilli can only survive 18 hours on silver tablets, and diphtheria bacilli can only survive for 3 days on silver tablets. If the skin is scratched and there is no medicine for a while, put silverware on the wound immediately to prevent infection.
Four silver-containing drugs, silver nitrate, protein silver, silicon carbon silver and sulfadiazine silver, have been included in modern pharmacopoeia, which are used to treat conjunctivitis, gonorrhea, cystitis, dysentery, enteritis, burns and other diseases.
To sum up, silver ions have antibacterial and bactericidal functions and have been recognized by human beings since ancient times. Therefore, activated carbon loaded with silver ions is often used for water purification. As for the decomposition of formaldehyde and harmful gases, there is no scientific basis.