Chemical heard good people, more clean cup brush?

Following do Liangpi (cold noodle heard people learn better polymer is also doing good? Yes, yes!), We found that people with good chemistry, as if the cup can be more clean brush. Surely the fear many people have been dominated by \”chemical formulas.\” You may remember, chemistry teacher always talking about: When cleaning glass container, if the container surface is neither covered drops of water, above water and not stocks shed, as evidenced by a clean container.

听说化学好的人,杯子刷得更干净?
did not wash clean tube

However, Xiao Bian believe that most people just remember this rule, but did not understand the hidden principles. Now, let us see what the scientific principles which in the end yes.

and non-invasive infiltration

we have in the past the park to watch the lotus experience. If you look closely, you will find that the surface of the lotus leaf drop is usually full round spherical form of small droplets, it is easy to swing with the blade and rolled.

听说化学好的人,杯子刷得更干净?
drops lotus leaf surface

Other plant leaves, especially yellow blade above puddles of water droplets is usually attached to the leaf surface, a substantially semi-ellipsoidal. The same water is what causes the differences in shape them? In fact, this phenomenon is called wetting and non-wetting on the physics, distinguished by the size of the contact angle. The contact angle refers to the angle of the liquid, solid surface, contacting air at three, curved liquid surface is formed with the solid surface, as shown below. When 听说化学好的人,杯子刷得更干净? In certain liquid droplet surface, the contact angle is small, almost bonded to the solid surface, a phenomenon called infiltration; while some liquid droplets on a solid surface, the contact angle is large, approximately spherical shape, this phenomenon is called non-wetting. Water on the lotus leaf lotus nonwettable precisely because the surface layer of a hydrophobic waxy, and further distribution of many small nano-particles, this structure can effectively increase the contact angle of water droplet. In addition to the liquid infiltration or not related to the microstructure of the material and the solid surface, also be influenced by the kind of liquid and solid surface impurities. 听说化学好的人,杯子刷得更干净? In general, a contact angle between water and a clean glass not greater than 90 °. In this case, the water can be well bonded to the glass surface, it will not form substantially spherical beads. However, once the glass heteroaryl taintedQuality and dirt, the contact angle will be significantly increased. When the contact angle is greater than 90 °, water glass surface was significantly drops will form. If more water collected in the water drops, larger water droplets by weight, it will flow down along a stranded glass surface. 听说化学好的人,杯子刷得更干净? talking about this, presumably small partners to understand why the chemistry teacher always said \”neither condenses into water droplets, and not shares shed\” even clean up. Unit is condensed into water and flows down into the water with the glass surface of the means of contact angle greater than 90 °, and the contact angles greater than 90 ° means that the glass dirt and impurities adhered on the surface, indicating that the glass is not clean.

molecular force – the nature of infiltration

earlier, we use physics to figure out infiltration and infiltration is not considered how the glass clean. But the curious little friends must ask, what is the nature of infiltration is it? This phenomenon is what is how to generate it? 听说化学好的人,杯子刷得更干净? Here, we went into the microscopic world, look solid and liquid surface in the end what happened? We know that most substances are composed of molecules or atoms, molecules or between atoms are not independent, there is interaction between each other, this interaction is called Molecular Forces , if there is a each spring invisible molecules up. All directions 听说化学好的人,杯子刷得更干净? of the liquid inside the molecule are other molecules adjacent to it, this will also be the natural molecule molecular forces from all other molecules. The size of these molecular force is almost the same, but different direction, so for a left-molecular forces, I can always find a corresponding approximately the same size, direction and force it to the right of offset. Similarly, a molecular force in any direction can be reversed with another offset corresponding to molecular force. Due to such offsetting, Overall, the interior of the liquid molecules almost unstressed. However, the situation is completely different liquid interface. For a molecule at the interface, the side with its millions of identical molecules, each adjacent to a molecule with molecular forces will pull it tight. And the other side of the molecule is empty, no molecules pull it, so in this direction it is almost unstressed.

听说化学好的人,杯子刷得更干净?
Liquid different positionsThe forces molecules

This means that each molecule will be on the liquid interface a strong force to the interior of the liquid, this force is pulling its numerous molecules of molecular forces in the liquid sum , we call surface tension . Due to the surface tension, the liquid surface will naturally shrink inwardly, so that it tends to minimize the surface area, i.e. the spherical form (equivalent to the minimum volume of a sphere surface area), which is microscopically due to the internal force of the liquid molecules are pulled inward the sake of molecules on the surface. The above is an isolated case within the droplet, the droplet and solid at the interface of what would happen then? In this case, one side of the liquid molecules at the interface is identical with its numerous liquid molecules, the liquid molecules are each adjacent inwardly pulling it, the tension is the sum of these previously described Liquid Surface Tension [ 123]. While the other side is composed of numerous solid molecules, these molecules can also interact with the liquid molecules at the interface, trying to pull the liquid molecules at the interface to their sum of these tensile forces, which we call Adhesion . Thus, the liquid molecules at the interface of the respective side surface tension is pulling, pulling the other side of the adhesion. Liquid momentary contact solid surfaces, if the adhesion is greater than the surface tension, the liquid molecules at the interface will be firmly dragged a solid surface, the contact area between the liquid and the solid surface increases, the contact angle decreases, i.e., the occurrence of infiltration. If adhesion is less than the surface tension, the liquid molecules on the side of the interface will be pulled back inside the liquid, the liquid with the solid surface contact area decreases, the contact angle is increased, approximately spherical droplet formation, non-wetting phenomenon. 听说化学好的人,杯子刷得更干净? For water, the waxy hydrocarbon molecules constituting material is not big attraction of the attraction between the water molecules of water molecules, thus drops to 听说化学好的人,杯子刷得更干净? Paraffin represented by a hydrophobic surface condenses the small drops into a ball. Various configurations of glass metal ion and attractive to water molecules radicals is greater than the attraction between the molecules of water, so water droplets drop fit tightly attached to the glass surface, generally not form a spherical shape. Once the glass surface contaminated with oil, the actual contact interface of the glass is no longer water molecules, but the greasy surface, in the hydrocarbon oil Attraction for water molecules is much smaller than glass, so, the water droplets will aggregate into small droplets in the oil, while larger droplets will flow down into strands. see little friends here have not surprised it? I did not expect this to wash the glass in the little things in life even hidden so profound physical principles! Molecular force seemingly always in touch with us actually affects our daily lives! In fact, the scientific principles in life, there are many hidden, as long as you have sufficient scientific knowledge and a pair of sharp eyes, will be able to find more wonderful truth in commonplace phenomenon.

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