Department of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada
Proc Natl Acad Sci U S A. 2021 Jun 8;118(23). doi: 10.1073/pnas.2105067118.
Liquid crystal displays (LCDs) have profoundly shaped the lifestyle of humans. However, despite extensive use, their impacts on indoor air quality are unknown. Here, we perform flow cell experiments on three different LCDs, including a new computer monitor, a used laptop, and a new television, to investigate whether their screens can emit air constituents. We found that more than 30 volatile organic compounds (VOCs) were emitted from LCD screens, with a total screen area-normalized emission rate of up to (8.25 ± 0.90) × 10 molecules ⋅ s ⋅ cm In addition to VOCs, 10 liquid crystal monomers (LCMs), a commercial chemical widely used in LCDs, were also observed to be released from those LCD screens. The structural identification of VOCs is based on a "building block" hypothesis (i.e., the screen-emitted VOCs originate from the "building block chemicals" used in the manufacturing of liquid crystals), which are the key components of LCD screens. The identification of LCMs is based upon the detailed information of 362 currently produced LCMs. The emission rates of VOCs and LCMs increased by up to a factor of 9, with an increase of indoor air humidity from 23 to 58% due to water-organic interactions likely facilitating the diffusion rates of organics. These findings indicate that LCD screens are a potentially important source for indoor VOCs that has not been considered previously.
液晶显示器（LCD）深刻地塑造了人类的生活方式。然而，尽管广泛使用，其对室内空气质量的影响尚不清楚。在这里，我们对三种不同的 LCD 进行了流动池实验，包括新的电脑显示器、使用过的笔记本电脑和新的电视机，以研究它们的屏幕是否可以排放空气成分。我们发现，超过 30 种挥发性有机化合物（VOC）从 LCD 屏幕中排放出来，总屏幕面积归一化排放量高达（8.25 ± 0.90）×10 分子 ⋅ s ⋅ cm。除了 VOC 之外，还观察到 10 种液晶单体（LCM）从这些 LCD 屏幕中释放出来，LCM 是一种商业上广泛用于 LCD 的液晶单体。VOC 的结构鉴定是基于“构建块”假设（即屏幕排放的 VOC 来源于制造液晶的“构建块化学品”），这是 LCD 屏幕的关键组成部分。LCM 的鉴定是基于目前生产的 362 种 LCM 的详细信息。由于水-有机相互作用可能促进有机物的扩散速率，室内空气湿度从 23%增加到 58%，导致 VOC 和 LCM 的排放率增加了 9 倍。这些发现表明，LCD 屏幕是一个以前未被考虑的室内 VOC 的潜在重要来源。
