字幕列表 影片播放 列印英文字幕 I remember watching this video online and being mesmerized. The more liquid they spilled on the items the more I thought “how was this even working?, what's going on here?” This is a superhydrophobic coating with properties that are seemingly impossible. But this material science field is making some exciting developments with materials that are even more impressive, and omniphobic. You might have heard of a term called hydrophobic, which can mean you're really scared of water, but in this case we're talking about an object being extremely water repellent. You might see this with water on a nonstick cooking pan when it beads up and rolls around with ease. But surfaces can not only be only hydrophobic, but omniphobic, meaning virtually any kind of liquid, from water to oil can slide off a surface with ease. Which isn't material you'd find in nature. The applications for a property like this are endless. They could help with the day to day cleaning of your house, make electronics water resistant, could help ships glide through water faster and even help heat transfer at nuclear power plants. Reasons like these are probably why scientists have spent years trying to get it right. Soo what's the hold up? Well let's start with the fact not all liquids are the same and they have different surface tensions, which causes them to interact with materials differently. Let's take water for example. Inside the liquid, there are intermolecular attractive forces at play, meaning the water molecules want to cling together. But when there are dissimilar molecules above them, like air for instance– those cohesive forces help the water molecules bond stronger with their neighbors - creating a thin “barrier” of sorts. This is the phenomenon that creates droplets, and help water bugs stay afloat. But like I mentioned before, this surface tension changes from liquid to liquid. Water has a very high surface tension whereas oil has a very low surface tension, so it seeps into everything. So knowing that, material scientists have created nanostructures made of small pillars spaced out just enough so that liquid can sit on small pockets of air. That way the liquid's own surface tensions lifts it up, causing all of these beads and droplets to form. And it totally works! Buut it relies on every pillar being perfect and this structure is only as strong as its weakest link. If one pillar breaks, the liquid can seep through the air pockets and there goes all your omniphobicity. And just to keep things more complicated, the materials also have to withstand condensation. If water vapor makes its way into the pockets within the omniphobic structure, it can condense into liquid and destroy repelling properties. This has been one of the biggest hurdles that material scientists have tried to overcome. And now researchers at MIT are tackling this problem head on, They've used nanotechnology to create not only microscopic, but condensation-resistant “T” shaped structures. The difference between this new development and earlier studies is that they made the air pockets disconnected, rather than connected. The disconnection would prevent a liquid from penetrating a single air pocket and spreading throughout the whole material, which helps with the issue of condensation! They've nailed a proof of concept, but they still need more work to bring it into market. But MIT isn't the only team working on omniphobic materials. A US Navy funded project from the University of Michigan made an omniphobic coating. Instead of building it, the material can be sprayed on. And as far as durability and clarity goes, it's one of the best coatings yet. Typically, researchers mix together a filler, giving it repelling properties, and a binder, giving it durability. But that doesn't always work, instead the team focused on a property called “miscibility”. They did mathematical calculations of the properties of many chemical substances in order to predict the best solution. And it worked. Their coating is clear, durable, can be applied to numerous surfaces and sheds just about any liquid. They're hoping it could last up to a year. Which sounds like a good goal since they're interested in putting it on naval ships to reduce drag and save on fueling cost. However, some of the chemicals they used might not be the safest and they want to reformulate so they're nontoxic and more commercially viable. They have a goal to get the coating out in the next year or two, so we'll keep a lookout. It's almost a race of who will create the perfect omniphobic innovation, but regardless who gets there first, the real winner will be us, reaping the benefits of decades of work like we always do and it's going to be amazing. Don't let this sponsor slide right by you, stick around and make your website, with Domain.com. Domain dot com has all your website needs, including dot com and dot net domain names and intuitive website builders.These guys are awesome - they're affordable, reliable, and have all the tools you need to build a new website. And if you want to brand yourself online, Domain dot com has over three hundred domain extensions to fit your needs, from dot pizza to dot space. The guys at Domain dot com love Elements, and to show their love they're giving you 20% off their already affordable prices. Use coupon code ELEMENTS at Domain dot com's checkout for 20% off. When you think domain names, think Domain dot com. One last fun fact before you go, The MIT design is so nice to look at because the periodic, nanoscale features on the surface diffract light, causing the colors in the image. If you love material sciences like this then go ahead and subscribe. And don't forget to watch this video about how we're making these even stranger materials better for electronics. Thanks so much for watching!
B1 中級 美國腔 液體排斥材料(These Liquid-Repelling Materials Defy Nature’s Design, Here’s How) 15 1 joey joey 發佈於 2021 年 04 月 12 日 更多分享 分享 收藏 回報 影片單字