Water electret charging based polypropylene/electret masterbatch composite melt-blown nonwovens with enhanced charge stability for efficient air filtration

ABSTRACT

With rapidly increasing demand for clean air, especially in this covid era, high efficiency filtration materials have gained massive significance and have become need of the hour. Currently, corona-electret-based filtration materials are the most used filtration materials. However, their instability in hot and humid environment demands for designing better and stable alternative filtration materials. Herein, we report novel electret polypropylene/electret masterbatch (PP-EM) composite melt-blown nonwovens with enhanced charge stability using water electret charging (WEC). WEC based nonwovens not only display improved the filtration efficiency (99.3%) but also offer tuned pore size to reduce the pressure drop from 71.6 Pa to 63.2 Pa. Significantly, the micro mechanism of triboelectric initiation between single fiber and deionized water in WEC has also been proposed. Benefiting from the process of charging by friction and hot air drying, the charge stored inside the fibers is insensitive to temperature and humidity. The successful fabrication of WEC PP-EM composite melt-blown nonwovens paves the pathway forward for the design and development of air filters with reinforced charge stability.