Hybrid membrane with controllable surface microroughness by micro-nano structure processing for diluted PM_2.5 capture

Area of Science:

• Materials Science
• Environmental Science
• Nanotechnology

Background:

• Air particulate matter pollution poses significant health risks, making effective PM2.5 capture crucial.
• Existing air quality indices are challenging to meet consistently due to pollution levels.

Purpose of the Study:

• To develop an efficient and scalable hybrid membrane for capturing fine particulate matter (PM2.5).
• To investigate the surface micro-nano structure's role in enhancing filtration performance.

Main Methods:

• A one-step method was used to prepare halloysite nanotubes/polyvinyl alcohol (HNTs/PVA) hybrid membranes.
• The composite membrane incorporated 60 wt% halloysite, creating a controllable microroughness surface and hierarchical structure.

Main Results:

• The HNTs/PVA membrane achieved 45.35% filtration efficiency with a low pressure drop of 41.57 Pa.
• A PM index value of approximately 16.54 was recorded, surpassing stringent Chinese government standards (PM2.5 < 35 μg/m³).
• The filtration mechanism involves both obstruction and adsorption facilitated by the membrane's unique structure.

Conclusions:

• The one-step method effectively creates a versatile hybrid membrane for PM2.5 capture.
• This technology shows great potential for scalable application in residential and public areas to mitigate air pollution.
• The developed membranes can be adapted for various polymers, offering broad applicability in air filtration solutions.