Self-assembled hydrophobic out-coating of the surface of porous adsorbents for moisture resistance and warfare-agent protection

Abstract

Personal protective equipment (PPE) comprising activated carbon fabrics (ACFs) is required to protect an individual against chemical warfare agents (CWAs) used as chemical weapons. ACFs has micropores, high surface area, and oxygen functional groups. The nucleophilic oxygen functional groups assist electrophilic CWAs adsorption by H-bonding and nucleophilic interaction. Due to many oxygen functional groups, ACF exhibit excellent CWAs adsorption performance. However, they are sensitive to moisture and difficult to selectively adsorb because of their characteristics, which limit their practical use and storage. Herein, we report a hydrophobic out-coating method that imparts hydrophobicity to only the ACF surface while maintaining the inherent structure and microporosity. The hydrophobic out-coated ACF (NML-F) is prepared by self-assembling hydrophobic agents on the ACF surface through a selective urethane reaction with the water affinity groups. NML-F is prepared by immersing ACF in a precursor solution. NML-F has a hydrophobic surface without blocking the microporous structure of ACF by controlling the reaction time. The hydrophobic surface of NML-F enables antimoisture adsorption and selective adsorption. NML-F as PPE shows excellent comfort and effective protection against sulfur mustard (HD) in high humid condition.