Direct Blow-Spinning of Nanofibers on a Window Screen for Highly Efficient PM<sub>2.5</sub> Removal.

Khalid, Bilal; Bai, Xiaopeng; Wei, Hehe; Huang, Ya; Wu, Hui; Cui, Yi · Nano Lett · 2017

basic_science · Level V

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Abstract

Particulate matter (PM) pollution has caused many serious public health issues. Whereas indoor air protection usually relies on expensive and energy-consuming filtering devices, direct PM filtration by window screens has attracted increasing attention. Recently, electrospun polymer nanofiber networks have been developed as transparent filters for highly efficient PM<sub>2.5</sub> removal; however, it remains challenging to uniformly coat the nanofibers on window screens on a large scale and with low cost. Here, we report a blow-spinning technique that is fast, efficient, and free of high voltages for the large-scale direct coating of nanofibers onto window screens for indoor PM pollution protection. We have achieved a transparent air filter of 80% optical transparency with >99% standard removal efficiency level for PM<sub>2.5.</sub> A test on a real window (1 m × 2 m) in Beijing has proven that the nanofiber transparent air filter acquires excellent PM<sub>2.5</sub> removal efficiency of 90.6% over 12 h under extremely hazy air conditions (PM<sub>2.5</sub> mass concentration > 708 μg/m<sup>3</sup>). Moreover, we show that the nanofibers can be readily coated on the window screen for pollution protection and can be easily removed by wiping the screen after hazardous days.