Song Yufeng, Peng Cheng, Iqbal Zafar, Sirkar Kamalesh K, Peterson Gregory W, Mahle John J, Buchanan James H
Department of Chemical and Materials Engineering, New Jersey Institute of Technology, University Heights, Newark, New Jersey 07102, United States.
Materials Science and Engineering, New Jersey Institute of Technology, University Heights, Newark, New Jersey 07102, United States.
ACS Appl Mater Interfaces. 2022 Jul 13;14(27):31321-31331. doi: 10.1021/acsami.2c07989. Epub 2022 Jun 30.
Garments protective against chemical warfare agents (CWAs) or accidently released toxic chemicals must block the transport of toxic gases/vapors for a substantial time and allow moisture transport for breathability. These demands are challenging: either the barriers block CWAs effectively but have poor breathability or barriers have excellent breathability but cannot block CWAs well. Existing protective garments employ large amounts of active carbon, making them quite heavy. Metal-organic framework (MOF)-based adsorbents are being investigated as sorbents for CWAs. Breathable laminate of graphene oxide (GO) flakes supported on a porous membrane reduces permeation rates of CWA simulants substantially. We developed a multilayered membrane-based flexible barrier: GO laminate-based membrane over a MOF nanocrystal-filled expanded polytetrafluorethylene (ePTFE) membrane having submicrometer pores. The GO laminate-based layer developed a steady breakthrough concentration level almost 2 orders of magnitude below the usual breakthrough level. This highly reduced level of CWA was blocked by the MOF nanocrystal-filled membrane substrate layer over a highly extended period. We demonstrated the blocking of CWAs, mustard (HD), soman (GD), a sarin simulant [dimethyl methyl phosphonate (DMMP)], and ammonia for an extended period while the moisture transmission rate was substantial. The times for complete blockage of ammonia, HD, GD, and DMMP were 2750 min, 1075 min, 176 min, and 7 days, respectively. This remarkable performance resulted from a very low steady-state penetrant permeation through GO-laminate membrane and substantial penetrant sorption by MOF nanocrystals; furthermore, both layers show high moisture vapor transmission.
用于防护化学战剂（CWAs）或意外释放的有毒化学品的服装必须在相当长的时间内阻止有毒气体/蒸汽的传输，并允许水分传输以保证透气性。这些要求颇具挑战性：要么屏障能有效阻挡化学战剂，但透气性差；要么屏障透气性极佳，但无法很好地阻挡化学战剂。现有的防护服使用大量活性炭，使其相当沉重。基于金属有机框架（MOF）的吸附剂正在作为化学战剂的吸附剂进行研究。负载在多孔膜上的氧化石墨烯（GO）薄片制成的透气层压板可大幅降低化学战剂模拟物的渗透率。我们开发了一种基于多层膜的柔性屏障：在具有亚微米级孔隙的填充MOF纳米晶体的膨体聚四氟乙烯（ePTFE）膜上覆盖基于GO层压板的膜。基于GO层压板的层形成了一个稳定的突破浓度水平，几乎比通常的突破水平低2个数量级。如此低水平的化学战剂在很长一段时间内被填充MOF纳米晶体的膜基底层阻挡。我们展示了在很长一段时间内对化学战剂芥子气（HD）、梭曼（GD）、一种沙林模拟物[甲基膦酸二甲酯（DMMP）]和氨气的阻挡，同时水分传输率很高。氨气、HD、GD和DMMP完全被阻挡的时间分别为2750分钟、1075分钟、176分钟和7天。这种卓越的性能源于通过GO层压板膜的极低稳态渗透物渗透率以及MOF纳米晶体对渗透物的大量吸附；此外，两层都显示出高水汽传输率。
