Metal organic framework against chemical warfare agents in gas adsorption

• Main Author: Chia, Chan Wing
• Other Authors: Zhao Yanli
• Format: Theses and Dissertations
• Language: English
• Published: 2019
• Subjects: Science::Chemistry
• Online Access: https://hdl.handle.net/10356/106783; http://hdl.handle.net/10220/49679
• Institution: Nanyang Technological University

Metal Organic Frameworks (MOFs) are a class of porous materials with highly desirable properties that enabled these materials to deliver excellent results to a wide range of application such as gas storage, gas capture, and catalysis. These properties make MOFs a potential alternative to be deployed as an active adsorbent and decontaminant against chemical warfare agents rather than the conventional approach of using activated carbon. In this study, two representative MOFs, HKUST-1 and UiO-66, were chosen as test specimen to evaluate its performance by doing a comparison with activated carbon, the widely used adsorbent in chemical protective equipment. The test methodology (Chapter 2) includes the synthesis of the two MOFs, and stored them in standard room condition (STP) for a period of six months. These aged MOFs were then exposed to a constant stream of HD vapour at a concentration of 5 mg/m3, for a period of 24 hours to determine its adsorption capacity and its first breakthrough volume. The test results (Chapter 3) illustrated the structural stability of the two MOFs under pro-longed storage in room condition. The aged MOFs retained their structure and crystallinity with indication on the presence of water picked up from the environment during storage. However, the presence of water did not hinder the MOFs from capturing HD vapour for a period of 24 hours. In comparison with activated carbon, the aged MOFs adsorption capacity for HD were as good. For HKUST-1, it outperformed activated carbon by having a significant longer first breakthrough volume. Despite the promising results, more work has to be done to ensure a wide adoption of MOFs in the area of chemical defense. Recommendation on future work (Chapter 4) includes the extension of this study to the different classes of chemical agents and toxic gases, such as the nerve agents and toxic industrial chemicals (TICs). Studies are needed to demonstrate the catalytic degradation reaction will occur in the vapour phase for a wide range of chemical agents and toxic gases. Novel MOFs could also be designed to include useful functionalities, such as the detection of CWAs, to yield smart materials for deployment in the three aspects of mitigation efforts in chemical defense.