For a long time, it was believed that rainwater damages objects\nbecause its acidic and saline content dissolves paint and erodes metal\nsurfaces. However, recent research has uncovered a far more powerful\ncause. Raindrops actually carry an electrical charge strong enough to\ninstantaneously puncture protective coatings, acting like miniature\nlightning strikes every time it rains.<\/p>\n
This finding implies that our current methods for protecting\nvehicles, buildings, and outdoor equipment may be inadequate, according\nto reports from Ars Technica and the journal Nature. Researchers from\nthe Max Planck Institute for Polymer Research in Germany discovered that\nas water droplets slide down any surface\u2014be it leaves, walls, windows,\nor car bodies\u2014they absorb electrical charges from the surfaces they\ntraverse. These seemingly ordinary droplets can carry electrical\nvoltages of up to thousands of volts.<\/p>\n
When these droplets strike another surface, the charge jumps,\npuncturing the coating much like a spark jumping between two poles. This\nmeans the damage to paint layers is not merely due to water slowly\ndissolving the coating. Instead, the phenomenon resembles microscopic\nlightning strikes penetrating the paint layer directly to the metal\nunderneath. Once the paint layer is breached, salt and acid-laden water\nenter, accelerating rust and much more severe damage.<\/p>\n
How can raindrops puncture paint? In the study, researchers dropped\nwater droplets, sized like raindrops, down an inclined surface so the\nwater would slide before hitting a copper plate coated with a\nnanometer-thick protective layer. After approximately 3,000\ndroplets\u2014equivalent to several hours of moderate rain\u2014the protective\nlayer, which was designed to be acid and water-resistant, was punctured\nthrough to the metal.<\/p>\n
Water that fell directly without sliding and carried no electrical\ncharge did not damage the protective layer at all. This proves that the\ndamage is caused by the electrical charge carried by the droplets,\nrather than the properties of the water itself. As the droplets approach\nthe metal surface, the charge forms an increasingly strong electric\nfield until it exceeds the resistance of the coating, resulting in an\ninstantaneous electrical discharge that pierces the layer. Protective\nlayers designed to withstand water and chemicals were not designed to\nwithstand this electrical voltage.<\/p>\n
The damage starting from these small holes expands over time. After\nabout 50,000 droplets, the holes widen to one millimetre. As the holes\ngrow larger, more water becomes trapped, further accelerating the\ndegradation. This means that objects frequently exposed to rain do not\njust suffer slow damage, but rather damage that accelerates over\ntime.<\/p>\n
This discovery suggests that almost all current protective coatings\nused for cars, bridges, ships, and buildings are inadequate.\nHistorically, protective materials have been chosen based on their\nresistance to water and chemicals, without considering their resistance\nto the electrical voltage carried by raindrops. Researchers noted that\nthicker protective layers can withstand these electrical discharges, as\na thicker layer weakens the electric field. However, not all objects can\nsupport thick coatings; window glass, aircraft coatings, and outdoor\nelectronics must remain thin and lightweight. Consequently, researchers\nsuggest the design of new protective materials that are not only water\nand acid-resistant but also capable of resisting electrical voltage.<\/p>", "url": "https:\/\/jawawa.id\/newsitem\/new-phenomenon-car-paint-pierced-by-raindrops-leading-to-rust-1788271018", "image": "" }, "sponsor": "Okusi Associates", "sponsor_url": "https:\/\/okusiassociates.com" }