Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States.
Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, United States.
ACS Appl Mater Interfaces. 2022 Jun 8;14(22):25135-25146. doi: 10.1021/acsami.2c04165. Epub 2022 May 25.
N95 respirator face masks serve as effective physical barriers against airborne virus transmission, especially in a hospital setting. However, conventional filtration materials, such as nonwoven polypropylene fibers, have no inherent virucidal activity, and thus, the risk of surface contamination increases with wear time. The ability of face masks to protect against infection can be likely improved by incorporating components that deactivate viruses on contact. We present a facile method for covalently attaching antiviral quaternary ammonium polymers to the fiber surfaces of nonwoven polypropylene fabrics that are commonly used as filtration materials in N95 respirators via ultraviolet (UV)-initiated grafting of biocidal agents. Here, C-quaternized benzophenone is simultaneously polymerized and grafted onto melt-blown or spunbond polypropylene fabric using 254 nm UV light. This grafting method generated ultrathin polymer coatings which imparted a permanent cationic charge without grossly changing fiber morphology or air resistance across the filter. For melt-blown polypropylene, which comprises the active filtration layer of N95 respirator masks, filtration efficiency was negatively impacted from 72.5 to 51.3% for uncoated and coated single-ply samples, respectively. Similarly, directly applying the antiviral polymer to full N95 masks decreased the filtration efficiency from 90.4 to 79.8%. This effect was due to the exposure of melt-blown polypropylene to organic solvents used in the coating process. However, N95-level filtration efficiency could be achieved by wearing coated spunbond polypropylene over an N95 mask or by fabricating N95 masks with coated spunbond as the exterior layer. Coated materials demonstrated broad-spectrum antimicrobial activity against several lipid-enveloped viruses, as well as and bacteria. For example, a 4.3-log reduction in infectious MHV-A59 virus and a 3.3-log reduction in infectious SuHV-1 virus after contact with coated filters were observed, although the level of viral deactivation varied significantly depending on the virus strain and protocol for assaying infectivity.
N95 口罩作为有效的物理屏障，可防止病毒通过空气传播，尤其在医院环境中。然而，传统的过滤材料，如无纺聚丙烯纤维，本身没有抗病毒活性，因此，随着佩戴时间的增加，表面污染的风险会增加。通过在接触时使口罩具有灭活病毒的功能，有可能提高口罩的防护能力。我们提出了一种简便的方法，通过光引发的生物杀灭剂接枝，将抗病毒季铵盐聚合物共价附着到通常用作 N95 口罩过滤材料的无纺聚丙烯纤维表面上。在这里，C-季铵化苯甲酮同时聚合并接枝到熔喷或纺粘聚丙烯织物上，使用 254nm 的紫外光。这种接枝方法生成了超薄的聚合物涂层，赋予了永久的阳离子电荷，而不会显著改变纤维形态或过滤层的空气阻力。对于熔喷聚丙烯，它构成了 N95 口罩的主动过滤层，对于未涂层和涂层的单层样品，过滤效率分别从 72.5%降至 51.3%。同样，直接将抗病毒聚合物应用于完整的 N95 口罩，使过滤效率从 90.4%降至 79.8%。这种效果是由于熔喷聚丙烯暴露于涂层过程中使用的有机溶剂。然而，通过在 N95 口罩上佩戴涂覆的纺粘聚丙烯或通过使用涂覆的纺粘聚丙烯作为外层面制造 N95 口罩，可以实现 N95 级别的过滤效率。涂覆材料对几种脂质包膜病毒以及 和 细菌表现出广谱抗菌活性。例如，与涂覆的过滤器接触后，观察到传染性 MHV-A59 病毒减少了 4.3 个对数，传染性 SuHV-1 病毒减少了 3.3 个对数，但病毒失活的程度因病毒株和检测感染性的方案而异。
