The reason for the uneven distribution of electrons is that electrons are out of orbit due to external forces, which include various energies (such as kinetic energy, potential energy, thermal energy, chemical energy, etc.). ). In daily life, any two objects with different materials will generate static electricity after contact out.
When two different objects touch each other, one object will lose some charges, for example, electrons will be transferred to the other object to make it positively charged, and the other object will get some remaining electrons to be negatively charged. If it is difficult to neutralize the charge in the separation process, the charge will accumulate and make the object electrostatic. Therefore, when an object contacts and separates from other objects, it will be charged with static electricity. Usually peeling off a plastic film from an object is a typical "contact" electrification, and the static electricity generated by undressing in daily life is also a "contact" electrification.
Solids, liquids and even gases will be charged with static electricity due to contact. This is because gas is also composed of molecules and atoms. When air flows, molecules and atoms will also produce "contact" and electricity.
We all know friction electrification, but we seldom hear of contact electrification. Triboelectrification is essentially a process of contact and separation, resulting in the imbalance of positive and negative charges. Friction is a process of continuous contact and separation. Therefore, triboelectrification is essentially contact electrification. In daily life, all kinds of objects may generate static electricity due to movement or friction.
Another common electrification is induction electrification. When a charged object approaches an uncharged object, it will induce negative electricity and positive electricity at both ends without electrical conductor.
In dry and windy autumn, we often encounter this phenomenon in our daily life: when we take off our clothes and sleep at night, we often hear a crackling sound in the dark, accompanied by blue light. When you meet and shake hands, as soon as your fingers touch each other, you will suddenly feel the tingling of your fingertips, which is shocking; When I get up in the morning to comb my hair, my hair tends to "float", and the more I manage it, the more chaotic it is. When you pull the door handle and turn on the tap, you will get an electric shock, and you will often make a "bang, bang" sound. This is static electricity generated in the human body. All the above phenomena are the result of the external "discharge" of static electricity in the body.
When the human body is active, the friction between skin and clothes, and the friction between clothes will generate static electricity. With the increase of household appliances and the increase of people wearing chemical fiber clothes in winter, the electrostatic charges generated by household appliances will be absorbed and accumulated by the human body. In addition, the walls and floors of the room are mostly insulators, and the air is dry, which is more susceptible to static interference.
Because the skin of the elderly is relatively dry than that of the young, and the cardiovascular system of the elderly is aging, the anti-interference ability is weakened, and the elderly are more susceptible to static electricity. In the elderly with various diseases of cardiovascular system, static electricity will aggravate the condition or induce arrhythmia such as ventricular premature beats. Too much static electricity often makes people fidget, headache, chest tightness, dyspnea and cough.
In order to prevent the occurrence of static electricity, it is necessary to maintain a certain humidity indoors, often mop the floor, often sprinkle water, or humidify with a humidifier; Take a bath and change clothes frequently to eliminate the static charge accumulated on the surface of human body. When you find that your hair can't be combed, soak the comb in water for a while, and then comb your hair after the static electricity is eliminated. After taking off your clothes, gently touch the wall with your hands, and touch the wall with your hands before touching the door handle or faucet to "discharge" the static electricity in your body, so as not to hurt you. For the elderly, we should choose soft and smooth cotton or silk underwear and underwear, and try not to wear chemical fiber clothing to minimize the harm of static electricity.
How to prevent static electricity
When the human body is active, the friction between skin and clothes, and the friction between clothes will generate static electricity. With the increase of household appliances and the increase of people wearing chemical fiber clothes in winter, the electrostatic charges generated by household appliances will be absorbed and accumulated by the human body. In addition, the walls and floors of the room are mostly insulators, and the air is dry, which is more susceptible to static interference.
Because the skin of the elderly is relatively dry than that of the young, and the cardiovascular system of the elderly is aging, the anti-interference ability is weakened, and the elderly are more susceptible to static electricity. In the elderly with various diseases of cardiovascular system, static electricity will aggravate the condition or induce arrhythmia such as ventricular premature beats. Too much static electricity often makes people fidget, headache, chest tightness, dyspnea and cough.
In order to prevent the occurrence of static electricity, it is necessary to maintain a certain humidity indoors, often mop the floor, often sprinkle water, or humidify with a humidifier; Take a bath and change clothes frequently to eliminate the static charge accumulated on the surface of human body. When you find that your hair can't be combed, soak the comb in water for a while, and then comb your hair after the static electricity is eliminated. After taking off your clothes, gently touch the wall with your hands, and touch the wall with your hands before touching the door handle or faucet to "discharge" the static electricity in your body, so as not to hurt you. For the elderly, we should choose soft and smooth cotton or silk underwear and underwear, and try not to wear chemical fiber clothing to minimize the harm of static electricity.
1, wash your hands before going out, or put your hands on the wall to remove static electricity, and try not to wear fancy clothes.
2. In order to avoid electrostatic strike, you can use small metal devices (such as keys) and cotton cloth to touch doors, door handles, faucets, chair backs, bed railings, etc. To eliminate static electricity, and then touch them with your hands.
3. Wear cotton underwear.
4. When you are ready to get off, hold the gear with your right hand, then touch the iron part below with your fingers, then open the door, and put your left hand on the iron part of the door, but don't let go of your left hand, then let go of your right hand and get off. At this time, if you hold the door with your right hand, you will not get an electric shock. . Then push hard and it's done ~ ~
5. To deal with static electricity, we can adopt both "prevention" and "release". "Prevention", we should try to choose pure cotton products as fabrics for clothes and home decoration, and try to avoid using chemical fiber carpets and furniture with plastic as surface materials to prevent friction and electrification. Try to stay away from TV, refrigerator and other electrical appliances to prevent induction electrification. "Discharge" is to increase humidity and make local static electricity easy to release. When you turn off the TV and leave the computer, wash your hands and face immediately, so that the electrostatic charge on the skin surface can be released in the water. Try to choose high moisturizing cosmetics in winter. Commonly used humidifier. Some people like to keep ornamental fish and daffodils indoors, which is also a good way to adjust indoor humidity.
In addition, I recommend an economical and practical humidification method: put a basin of water under the heating, use an old towel (or absorbent cloth), put one end in the water and the other end on the heating, so that about three liters of water can be evaporated into the house day and night. If every heater does this, the whole room will feel damp and pleasant. it wont hurt you to try it
6. Bathing and changing clothes frequently can effectively eliminate the static electricity accumulated on the surface of human body.
In daily life, people often accumulate static electricity because of clothes, climate, friction and other reasons. When you suddenly come into contact with metal, you will feel the pain of electric shock, which may even cause certain psychological pressure when it happens frequently at a certain stage. If you avoid contact with iron for a while, you may accumulate more charges and get a bigger electric shock sooner or later.
Here are two tips to help prevent this kind of electric shock.
1. indoors, static electricity may be generated after the carpet rubs the sole, and the wind outside may make the body charged. Be careful to touch the iron gate when entering and leaving at this time, and your hands may get an electric shock. After repeatedly encountering such a situation, you can take the following measures to avoid electric shock:
When touching the iron gate, don't touch the iron gate directly with your hands. Instead, grab a bunch of keys in your pocket with your hand (usually it won't get an electric shock), and then touch the iron gate with the tip of the key, so that the electricity on your body will be discharged without getting an electric shock.
Principle: The pain of hand discharge is caused by high-voltage discharge. When discharging, the hand suddenly touches the iron gate very little, resulting in instantaneous high voltage. If you take the key out of your pocket, first press the key in a large area (a string of keys itself can't transfer much charge, so it won't get an electric shock at this time), and then use the key tip to touch the big conductor. At this time, the contact point of discharge is not a certain point on the skin of your hand, but the tip of the key, so your hand will not feel pain (maybe the key will! -If it hurts.
2. You often get an electric shock when you get off a taxi. It is mainly the static electricity accumulation caused by the friction between the body and the seat when getting off the bus. When closing the door after getting off the bus, the hand suddenly touches the iron gate and will get an electric shock.
When this often happens, it is best to pay attention to: when you get off the bus, that is, when your body rubs against the seat, you can hold the metal door frame in advance, so that static electricity can be discharged from your body at any time when it is generated by friction, so as to avoid discharging when you suddenly hit the iron gate after getting off the bus.
Advantages and disadvantages of static electricity
We know that friction can generate electricity. The positive and negative charges after friction are bound to the charged body. It can't move directionally like the charge in a wire, so people call it electrostatic charge, or static electricity for short.
There are many hazards of static electricity, first of all, it comes from the interaction of charged bodies. When the aircraft fuselage rubs against air, water vapor, dust and other particles, it will make the aircraft charged. If no measures are taken, it will seriously interfere with the normal work of aircraft radio equipment and make the aircraft deaf and blind. In a printing factory, the static electricity between pages will make the pages stick together, making it difficult to separate them, which will bring trouble to printing; In the pharmaceutical factory. Because static electricity attracts dust, the drug can't reach the standard purity; When the TV is turned on, the static electricity on the screen is easy to absorb dust and oil, forming a dust film, which reduces the clarity and brightness of the image; The common dust that is difficult to pat off on blended clothes is also a ghost of electrostatic rammer. The second biggest hazard of static electricity is that it may explode because some flammable objects are ignited by electrostatic sparks. In the dark night, when we take off our nylon and woolen clothes, there will be sparks and a beep, which is basically harmless to the human body. But on the operating table, in addition to electric spark, it will also cause the explosion of anesthetic, hurting doctors and patients; In coal mines, gas explosion will be caused, resulting in the death and injury of workers, and the mine will be scrapped.
In a word, electrostatic hazards are caused by electricity and electrostatic sparks, and the most serious electrostatic discharge in electrostatic hazards causes fires and explosions of combustible substances. People often say that preventive measures are generally to reduce the flow and velocity, transform the process links with strong electrification and adopt equipment and materials with less electrification. The simplest and most reliable method is to ground the equipment with wires, which can attract charges to the earth and avoid electrostatic accumulation. Careful passengers will probably find out; The discharge brushes are installed at the wing tip and tail of the aircraft. When the plane lands, in order to prevent passengers from getting electric shock when flying down, special grounding tires or grounding wires are often used on the landing gear of the plane. Release the static charge generated by the aircraft in the air. We often see a chain dragging at the tail of the tanker, which is the grounding wire of the tanker. Properly increasing the humidity of the working environment and letting the charge discharge at any time can also effectively eliminate static electricity. It is for this reason that it is not easy to do a good electrostatic test in wet weather. The antistatic agent studied by the researchers can eliminate the static electricity inside the insulator well.
However, everything has two sides. For the troublemaker of electrostatic hiding. As long as we understand its temper, foster strengths and avoid weaknesses, we can also make it serve mankind. For example, electrostatic printing, electrostatic spraying, electrostatic flocking, electrostatic dust removal, and Hongkong Electric sorting technology have been widely used in industrial production and life. Static electricity has also begun to play a great role in seawater desalination, pesticide spraying, artificial rainfall, low temperature freezing and many other aspects, and even electrostatic feeders and other electrostatic devices have been installed on spacecraft.