Chemists at Cornell University have discovered a way to use light and oxygen to upcycle polystyrene – a type of plastic found in many common items – into benzoic acid, a product stocked in undergraduate and high school chemistry labs and also used in fragrances, food preservatives, and other ubiquitous products.
聚苯乙烯泡沫塑料鸡蛋纸箱，硬塑料紧凑型盘子，红色饮用杯和许多其他常见产品由聚苯乙烯组成，占全球垃圾填埋场的三分之一。
康奈尔大学化学和化学生物学助理教授艾琳·斯塔奇（Erin Stache）领导的团队发现，这种反应甚至可以在阳光明媚的窗户中发生。
Their paper, "Chemical Upcycling of Commercial Polystyrene via Catalyst-Controlled Photooxidation“发表在《美国化学学会杂志》上。
In line with her lab's mission to tackle environmental concerns through chemistry, the new process is mild, climate-friendly and scalable to commercial waste streams, Stache said.
Moreover, the process is tolerant of additives inherent in a flow of consumer waste, including dirt, dyes and other types of plastics.
去年夏天，Stache的实验室在阳光明媚的窗户中进行了一些退化实验。在全年阳光强烈的地方，可以在户外进行反应。
"The advantage of using light is you can get exquisite control over the chemical process based on some of the catalysts we've developed to harness the white light. If we can use sunlight to drive the process, that's a win-win,"Stache said, noting that existing polymer recycling requires heating a polymer for melting and processing, which usually requires fossil fuel.
为了测试该工艺对与PS塑料混合的其他材料的耐受性，研究人员使用了几种产品，从包装材料到咖啡杯欧洲杯足球竞彩盖。
They found that three items – a white coffee cup lid, Styrofoam and a clear lid – degraded efficiently. A black coffee cup lid degraded less efficiently, possibly because the black dyes inhibit light penetration, Stache said.
"These results signify that our system could efficiently break down commercial samples of PS, even with additional composite and insoluble material,"她说。
为了证明可扩展性和潜在的商业应用，研究人员在3D打印的光电反应器中创建了一个带有两个注射器泵和两个LED灯的设置。大规模分解过程的效率与小批量相似。
"If we can make the process even more efficient, we can think about how to commercialize it and use it to address waste streams,"Stache said.
这项研究得到了国家科学基金会的部分支持。欧洲杯线上买球
来源：https://www.cornell.edu/