Biodegradable Polybutyrolactam Microfiber Membrane as a Highly Efficient Air Filter for PM2.5 Particle Filtration

Particulate matter (PM) pollution poses a significant threat to human health on a global scale. However, current conventional air filtration materials, made from nonbiodegradable petroleum-based components, contribute to resource consumption and waste emissions, and are unable to meet the public's demand for environmental protection and energy conservation. For the first time, we report environmentally friendly biobased biodegradable polybutyrolactam (also known as PA4) electrospun air filters with superior mechanical properties and high interception efficiency. Compared with the commercial particulate filtration efficiency of 95% polypropylene melt-blown nonwoven fabric (PFE95), the successfully prepared green biobased degradable PA4 electrospun microfiber membrane has a lighter texture (<3 mg/cm2) and high porosity (>80%) with as high as 99.85% for PM 2.5 filtration performance. In addition, the PA4 electrospun microfiber membranes also have very stable outstanding mechanical properties especially on tensile strength (≥4.25 MPa) and Young's modulus (≥34.82 MPa) at the same time. The biodegradability of PA4 electrospun microfiber membranes in campus soil was investigated, and the weight loss was approximately 88% within 49 days. This would not only make it a promising candidate for green and pollution-free air filtration but also provide insights into the design and development of composite membranes for multifuntionalities for various applications.