Membrane-supported metal organic framework based nanopacked bed for protection against toxic vapors and gases
Membrane-supported metal organic framework based nanopacked bed for protection against toxic vapors and gases
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DOI：
10.1016/j.seppur.2020.117406
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发表时间：
2020-11
影响因子：
8.6
通讯作者：
Yufeng Song;J. Chau;K. Sirkar;G. Peterson;U. Beuscher
中科院分区：
文献类型：
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作者：
Yufeng Song;J. Chau;K. Sirkar;G. Peterson;U. Beuscher
对小分子有毒气体的防御是防止化学和生物威胁以及工业事故中化学物质释放的一个重要方面。目前的防护口罩/服装不能有效地阻挡小分子有毒气体和蒸气，并在没有沉重负担的情况下保持水分传输能力。在这里，我们开发了UIO-66-NH_2金属有机骨架(MOF)纳米颗粒的纳米孔床，通过在微孔膨胀聚四氟乙烯(EPTFE)膜的孔道中合成它们。亚微米级的膜孔尺寸保证了MOF纳米颗粒具有较大的比表面积，能够有效地捕获/吸附有毒气体分子并与其发生反应。研究表明，在膜内和膜周围生长UIO-66-NH_2MOF的微孔ePTFE膜，在允许水分和氮气通过的同时，可以在相当长的时间内抵御氨气。研究还表明，负载MOF的ePTFE膜可以有效地抵御Cl2的入侵和2-氯乙基乙基硫化物(CEES)(一种硫芥末的模拟物)的入侵。经NH3穿透实验排出的MOF填充膜，可在60℃真空下加热一周方便地再生，一次再生膜可阻隔NH3 200-300分钟。这种膜/纳米孔床的透湿性远高于透气性阈值2000微克/平方米·天。结果表明，填充了反应性MOF纳米颗粒的微孔膜可以被设计为防止有毒气体/蒸气(如NH3和Cl2)的屏障，但对H2O和空气具有良好的渗透性。
Defense against small molecule toxic gases is an important aspect of protection against chemical and biological threat as well as chemical releases from industrial accidents. Current protective respirators/garments cannot effectively block small molecule toxic gases and vapors and retain moisture transmission capability without a heavy burden. Here, we developed a nanopacked bed of nanoparticles of UiO-66-NH2metal organic framework (MOF) by synthesizing them in the pores of microporous expanded polytetrafluoroethylene (ePTFE) membranes. The submicron scale size of membrane pores ensures a large surface area of MOF nanoparticles which can capture/adsorb and react with toxic gas molecules efficiently. It was demonstrated that the microporous ePTFE membrane with UiO-66-NH2MOF grown inside and around the membrane can defend against ammonia for a significant length of time while allowing passage of moisture and nitrogen. It was also demonstrated that the MOF-loaded ePTFE membrane could provide significant protection from Cl2intrusion as well as intrusion from 2-chloroethyl ethyl sulfide (CEES) (a simulant for sulfur mustard). Such MOF-filled membranes exhausted by NH3breakthrough experiments were regenerated conveniently by heating at 60 °C for one week under vacuum for further/repeated use; a single regenerated membrane could block NH3for 200–300 min. The moisture permeability of such a membrane/nanopacked bed was considerably above the breathability threshold value of 2000 g/m2-day. The results suggest that microporous membranes filled with reactive MOF nanoparticles could be designed as protective barriers against toxic gases/vapors, e.g., NH3and Cl2and yet be substantially permeable to H2O and air.