The capillary effect in a liquid occurs at the boundary of two media - moisture and gas. It leads to a curvature of the surface, making it concave or convex.
Water capillary effect
When the vessel is filled with H2O, its surface is even. However, the walls are bent. If they are wetted, the surface becomes concave; if they are dry, it becomes convex. The attraction of H2O molecules to the walls of the vessel is greater than to each other. This explains the capillary effect. The force lifts the H2O molecules until the hydrostatic pressure balances it.
Observations
As part of the experiments, the researchers tried to determine how the capillary effect depends on the length of the tube. In the course of observations, it was revealed that it does not depend on the length of the tube, the thickness of the vessel matters. In narrow spaces, the distance between the walls is small. As a result of the curvature, they are connected to each other. The capillary effect is also summed up. Accordingly, the level of H2O in a thin vessel may be higher than in a wide one.
Ground
There are pores in any soil. They also have a capillary effect. Pores are the same vessels, onlyvery small. In all soils, it is observed to one degree or another.
Molecules H2O rise despite gravity. The lifting height depends on the type of soil. On clay soils, it can be up to 1.5 m, and on sandy soils, up to 30 cm. This difference is related to the pore size. In sandy soils, they are very large, respectively, the capillary force is small. Clay particles are smaller. This means that the pores in the soil are smaller, and the effect is stronger.
Practical points
The capillary effect in the soil must be taken into account when designing and laying the foundation. As mentioned above, in clay soil, moisture can rise by 1.5 m. If the foundation is laid below this mark, then it will constantly be in the water. This, in turn, will negatively affect its bearing capacity. To protect the foundation from moisture, waterproofing is required.
Concrete
This material is used in the construction of the foundation. In concrete, as well as in soil, a capillary effect is also possible, because this material has a porous structure. Through the pores, moisture spreads deep and upwards.
If the sole of the foundation rests on wet soil, the water will rise, reach the plinth and go higher. This can lead to the destruction of all structures. To prevent such consequences, waterproofing is laid between the soil and the base of the foundation, the basement and the walls of the house.
Ultrasonic capillary effect
This phenomenon was discovered by Academician Konovalov. The scientist performed a fairly simple experiment. He attached a vessel with water to the emitter of the generator, lowering a capillary tube into it. According to natural laws, the force began to influence H2O, causing it to rise to a certain level. After turning on the ultrasonic generator, the water made a sharp jerk upwards. The academician repeated this experiment by adding a dye to the vessel. After turning on the generator, rarefaction and nodes of standing waves were clearly visible in the tube.
Conclusions
Academician Konovalov found that if water in a capillary fluctuates under the influence of an ultrasonic source, then the effect of raising its level sharply increases. The height of the column becomes sometimes several tens of times larger. At the same time, the rate of ascent also increases.
The scientist was able to experimentally prove that liquid is pushed not by capillary forces and radiation pressure, but by standing waves. Ultrasound constantly compresses the column and raises it. The process will go on until the pressure arising under the influence of waves is balanced by the liquid level.
Application
The ultrasonic effect is used in non-destructive testing methods for the production of semiconductor equipment. In the old days, to control the tightness of the transistor housing, the device was placed for three days in an acetone bath. The use of ultrasound can significantly reduce the time to 3-9 minutes. Discovery of Konovalovused when impregnating the windings of electric motors with insulating compounds, when dyeing fabrics - wherever moisture penetration into the pores is necessary.
Effect of vibration
Metal cutting processes, especially at high speeds, use lubricating coolants. Due to them, a decrease in friction, a decrease in the temperature of the tool, and an increase in its wear resistance are ensured. It is known that liquid can penetrate under the incisor. How does this happen if it is pressed tightly against the part at a pressure of up to 200 kg / cm², and under such conditions, on the contrary, the lubricant should be forced out from under the cutter?
It was not possible to explain this phenomenon by the capillary effect. First of all, the strength and speed of raising moisture is very small. In addition, they are due to surface tension. The lifting height decreases significantly with increasing temperature, which in the cutting zone can reach up to 300°C. Konovalov managed to prove that, in addition to the capillary effect, the vibration of the machine has an effect. It occurs during the processing of the workpiece. This vibration has a higher frequency and lower amplitude.
Explanation of some phenomena
For quite a long time, scientists could not explain the flowering of the royal primrose before the earthquake. This flower grows on about. Java. And locals consider him a predictor of trouble. According to Konovalov, powerful shocks of the crust are preceded by minor vibrations of different frequencies, including ultrasonic vibrations. They help speed up the movement of nutrients.compounds on the elements of the plant, activate metabolic processes, which ensures flowering.
Conclusion
As you can see, the capillary effect is one of the most common natural phenomena. Stems, leaves, trunk, branches of different plants are pierced by a huge number of channels. Nutrient compounds are delivered through them to all organs. The capillary effect is used in various fields of human activity: from tarring sleepers and creating special ceramic products impregnated with molten metals, to pickling cucumbers.
