Firstly, I am feeling great honor to be invited to write a blog paper here. So, I would like to share the story behind this work.
I come from Sichuan University, Chengdu. At the same time, I am also a local man in Chengdu, who has been living here for over 23 years. Recently, as the strategy of West China development, a huge number of factories settled in Chengdu. However, Chengdu lies in Sichuan basin, which is surrounded by mountains. This makes it difficult for the monsoon to blow away the industrial emission, leading to a serve particulate matter (PM) pollution, especially in winter. In the past, it was said that “Chengdu, Land of Abundance, a city once you come you do not want to leave.” But now, it seems less convincing.
Top: Air quality index of Chengdu in Dec, 2019. Bottom: The air quality changes in Chengdu.
Our groups have focused on the green functional materials based on ionic liquids (ILs) for over 10 years. ILs are a kind of devisable material which is composed of anions and cations. Since noticing the bad weather in Chengdu, we started attempting to use ILs as purification materials to capture the PMs (J. Mater. Chem. A 7, 4619-4625, (2019); Adv. Mater. Interfaces 5, 1700448, (2018)). We found that ILs possess an admirable electrostatic potential, which can influence the motions of PMs in air. This prompted us to coat ILs on some porous sponges to enhance the contact surface area with the PMs, and the strategy achieves a certain success.
Top: Illustration of the removal mechanism of the multilayer ILP@MF filter. Bottom: Personal face masks fabricated by self-powered ILP@MF filter.
Because it is made entirely of ions, the ILs with low viscosity often have good electrochemical properties, such as high conductivity and wide electrochemical window. Therefore, in this work, we prepared an air filter based on ILs and polymers (ILP) composites, which were coated onto the melamine-formaldehyde (MF) resin sponge. Then we provide an elect-power supply platform to the ILP@MF filter to form a high electric field at low voltage. The enhanced electrostatic interaction not only realized a high removal efficiency for large particles (PM2.5 and PM10), but also an admirable purification performance for nanoscale particles (NPs). Furthermore, the low voltage allows for a portable power supply (i.e. lithium cell or solar panel) to be included with the personal face masks.
The purpose of scientific research is to make life better. Although research on air-filtering can prevent people from being exposed to PM pollution, we call on factories to save energy and reduce emissions to resolve the problems of air pollutants from the source!
If you want to know further details of this work, please click here.