马里兰大学发明首个可以自动调节温度的织物

    马里兰大学新发明的织物可以在红外辐射通过时自动调节热量。“这是第一项允许我们动态选择红外辐射的技术，”化学与生物化学教授，该研究的发明人解释道。如果条件温暖潮湿，织物允许红外辐射（热量）通过。如果条件变得更凉爽和干燥，织物可以减少逸出的热量。

  “人体是一个完美的散热器。它可以快速散热，”马里兰大学物理学教授Min Ouyang说。“在过去，调节散热的唯一方法就是脱掉衣服或穿上衣服。但这种面料是一种真正的双向调节器。”

该织物由涂有导电金属的工程纱线制成。在炎热的条件下，纱线紧凑并激活涂层，改变织物与红外辐射相互作用的方式 - 使其成为可调节的窗帘，传递或阻挡热量。

    “你可以把这种耦合效应想象成无线电天线的弯曲，以改变它产生共振的波长或频率，”王说。“这是一种非常简单的思考方式，但想象一下将两个触角靠近在一起以调节它们拾取的电磁波的种类。当光纤靠近在一起时，它们相互作用的辐射会发生变化。在服装中，这意味着织物与人体散发的热量相互作用。“

    这是第一个纺织品调节与环境的热交换能力的研究。

    “这项开创性的工作为舒适调整服装提供了令人兴奋的新的可切换特性，”德克萨斯大学化学教授Ray Baughman说，他没有参与这项研究。“众所周知，纺织品会增加汗液或增加温度的孔隙度，以及传递与体温相关的红外辐射的纺织品。但是，为了适应环境条件而提供更高的舒适度，之前没有人找到一种方法来改变纺织品的孔隙率和红外透明度。“

First Fabric to Automatically Regulate Temperature

The material created regulates the amount of heat automatically as it passes through. "This is the first technology that allows us to dynamically gate infrared radiation," explains YuHuang Wang, a professor of chemistry and biochemistry and the study’s corresponding author. If conditions are warm and moist, the fabric allows infrared radiation (heat) to pass through. If conditions become cooler and drier, fabric reduces escaping heat.

"The human body is a perfect radiator. It gives off heat quickly," says Min Ouyang, professor of physics at UMD. "For all of history, the only way to regulate the radiator has been to take clothes off or put clothes on. But this fabric is a true bidirectional regulator."

The fabric was created from engineered yarn that is coated with conductive metal. Under hot conditions, strands of yarn compact and activate the coating changing the way the fabric interacts with infrared radiation—making it a tunable blind that transmits or blocks heat.

"You can think of this coupling effect like the bending of a radio antenna to change the wavelength or frequency it resonates with," Wang said. "It's a very simplified way to think of it, but imagine bringing two antennae to close together to regulate the kind of electromagnetic wave they pick up. When the fibers are brought closer together, the radiation they interact with changes. In clothing, that means the fabric interacts with the heat radiating from the human body."

This was the first study to show a textile’s capability of regulating heat exchange with the environment.

"This pioneering work provides an exciting new switchable characteristic for comfort-adjusting clothing," said Ray Baughman, a professor of chemistry at the University of Texas who was not involved in the study. "Textiles were known that increase porosity in response to sweat or increasing temperature, as well as textiles that transmit the infrared radiation associated with body temperatures. However, no one before had found a way to switch both the porosity and infrared transparency of a textile so as to provide increased comfort in response to environmental conditions."