馬里蘭大學(xué)新發(fā)明的織物可以在紅外輻射通過時(shí)自動調(diào)節(jié)熱量。“這是第一項(xiàng)允許我們動態(tài)選擇紅外輻射的技術(shù)，”化學(xué)與生物化學(xué)教授，該研究的發(fā)明人解釋道。如果條件溫暖潮濕，織物允許紅外輻射（熱量）通過。如果條件變得更涼爽和干燥，織物可以減少逸出的熱量。

  “人體是一個完美的散熱器。它可以快速散熱，”馬里蘭大學(xué)物理學(xué)教授Min Ouyang說。“在過去，調(diào)節(jié)散熱的唯一方法就是脫掉衣服或穿上衣服。但這種面料是一種真正的雙向調(diào)節(jié)器。”

該織物由涂有導(dǎo)電金屬的工程紗線制成。在炎熱的條件下，紗線緊湊并激活涂層，改變織物與紅外輻射相互作用的方式 - 使其成為可調(diào)節(jié)的窗簾，傳遞或阻擋熱量。

    “你可以把這種耦合效應(yīng)想象成無線電天線的彎曲，以改變它產(chǎn)生共振的波長或頻率，”王說。“這是一種非常簡單的思考方式，但想象一下將兩個觸角靠近在一起以調(diào)節(jié)它們拾取的電磁波的種類。當(dāng)光纖靠近在一起時(shí)，它們相互作用的輻射會發(fā)生變化。在服裝中，這意味著織物與人體散發(fā)的熱量相互作用。“

    這是第一個紡織品調(diào)節(jié)與環(huán)境的熱交換能力的研究。

    “這項(xiàng)開創(chuàng)性的工作為舒適調(diào)整服裝提供了令人興奮的新的可切換特性，”德克薩斯大學(xué)化學(xué)教授Ray Baughman說，他沒有參與這項(xiàng)研究。“眾所周知，紡織品會增加汗液或增加溫度的孔隙度，以及傳遞與體溫相關(guān)的紅外輻射的紡織品。但是，為了適應(yīng)環(huán)境條件而提供更高的舒適度，之前沒有人找到一種方法來改變紡織品的孔隙率和紅外透明度。“

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."