Zhang Haifeng, Liu Jinxin, Zhang Xing, Huang Chen, Jin Xiangyu
Engineering Research Center of Technical Textiles, Ministry of Education, College of Textiles, Donghua University No. 2999 North Renmin Road, Songjiang Shanghai 201620 China
RSC Adv. 2018 Feb 19;8(15):7932-7941. doi: 10.1039/c7ra10916d.
Particulate matter (PM) pollution has become a serious threat to public health, climate and ecosystems. Therefore, filtration materials with high filtration efficiency and low air resistance are in urgent need. Electret filters that can significantly improve filtration efficiency without increasing pressure drop are widely used for air filtration. However, long-term maintenance of the electrical charges on electret filters, particularly at high temperatures and in wet conditions, is still a challenge. Herein, we report the fabrication of a novel electret filter with a fluffy structure, high porosity and satisfactory filtration stability using polypropylene (PP) as the matrix polymer and magnesium stearate (MgSt) as the charge enhancer. Benefiting from the fluffy structure created by melt blown at a large die-to-collector distance (DCD), the pressure drop decreased from 67.0 Pa to 52.9 Pa at an air flow rate of 85 L min. Furthermore, the introduction of MgSt changed the crystal structure of the melt blown nonwovens, thus improving the electret properties to achieve a high filtration efficiency of 99.22%, a low pressure drop of 92 Pa and a satisfactory QF of 0.054 Pa. In particular, the electret filtration materials exhibited excellent filtration stability and loading performance. Thus, this electret material may become a good candidate for personal protective filtration materials against PM2.5.
颗粒物（PM）污染已对公众健康、气候和生态系统构成严重威胁。因此，迫切需要具有高过滤效率和低空气阻力的过滤材料。能在不增加压降的情况下显著提高过滤效率的驻极体过滤器被广泛用于空气过滤。然而，驻极体过滤器上电荷的长期维持，尤其是在高温和潮湿条件下，仍然是一个挑战。在此，我们报道了一种新型驻极体过滤器的制备，该过滤器以聚丙烯（PP）为基体聚合物、硬脂酸镁（MgSt）为电荷增强剂，具有蓬松结构、高孔隙率和令人满意的过滤稳定性。受益于在大模头到收集器距离（DCD）下通过熔喷形成的蓬松结构，在85 L/min的空气流速下，压降从67.0 Pa降至52.9 Pa。此外，MgSt的引入改变了熔喷非织造布的晶体结构，从而改善了驻极体性能，实现了99.22%的高过滤效率、92 Pa的低压降和0.054 Pa的令人满意的品质因数（QF）。特别是，驻极体过滤材料表现出优异的过滤稳定性和负载性能。因此，这种驻极体材料可能成为用于防护PM2.5的个人防护过滤材料的良好候选者。
