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开发一种替代方法来测量允许通过面罩的粒子大小,使用扫描电子显微镜进行测量

J Arenas-Alatorre¹, S Tehuacanero Cuapa¹, C Magaña-Zavala¹

¹Instituto de Física UNAM, Circuito de la Investigación Científica S/N, Ciudad Universitaria, Delegación Coyoacán, Mexico City, Mexico.

Microscopy research and technique

|March 20, 2025

概括

一种新的方法评估了使用盐水滴和扫描电子显微镜的面罩颗粒过效率. 结果显示,K95和KN95口罩允许小颗粒通过,而商业口罩具有不同的过能力.

科学领域:

材料科学材料科学材料科学
纳米技术纳米技术
公共卫生公共卫生

背景情况:

随着COVID-19的流行,人们越来越需要有效的呼吸道防护设备.
面罩的耗尽和质量变化需要可靠的测试方法.
像风洞这样的现有方法可能无法完全模拟粒子驱逐的现实世界场景.

研究的目的:

开发和验证一个用于评估面罩颗粒过效率的补充方法.
评估不同类型的面罩的性能,包括N95呼吸器和常见的商业面罩.
在模拟呼吸事件下量化颗粒通过面罩的尺寸和通道速度.

主要方法:

一种新的技术,使用60 PSI的重力养气刷枪,将20%的NaCl溶液喷到面罩上.
模拟咳或打喷事件,沉积时间为1秒.
采集了穿过面具的颗粒,使用带有扫描电子显微镜 (SEM) 幻灯片的样本持有器.
在黄金喷后使用场辐射SEM (FSEM) 分析颗粒大小 (0.21.0μm).

主要成果:

K95和KN95口罩允许85%和88%的NaCl颗粒 (0.21.0μm) 通过,分别具有低沉积密度 (0.1颗粒/μm2).
商用双层聚烯口罩允许大于5微米的颗粒通过.
商用三层面罩允许颗粒小到2微米通过.

结论:

开发的方法提供了一个对传统风洞测试的补充方法,用于面罩过.
在测试条件下,N95型口罩显示了微微粒的显著通过.
商用口罩对较小的空气颗粒提供有限的保护,三层面罩的性能优于两层面罩.

关键词:

在FSEM,FSEM是FSEM.在SARS-CoV-2中.面罩是面具的使用方式.面具效率面具效率面具效率面具效率

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