Towards industrializing metal-organic frameworks : scalable synthetic means and their transformation into functional textile materials

• Main Author: Teo, Wei Liang
• Other Authors: Zhao Yanli
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Science::Chemistry; Engineering::Materials
• Online Access: https://hdl.handle.net/10356/153504
• Institution: Nanyang Technological University

For over two decades, metal–organic frameworks (MOFs) have drawn significant attention in the scientific community. Compared to other porous material types, MOFs possess unique properties due to the presence of both metallic and organic components embedded within the framework structure. This gives rise to a multitude of structural variations via permutation and combination. Furthermore, post-synthetic methods for material modification allow for greater customizability to suit the intended purpose, with the hope to solve a wide variety of real-world problems. Indeed, the development of MOF for various practical applications has created fascinating new areas of research and pushed the boundary of scientific advancement. Despite overwhelming interests for this unique class of porous materials, the progress towards actual utilization falls short of the expectation due to the challenging transition from academia to industry. Despite their importance to the commercialization of MOFs, large-scale production and processing of MOFs materials are not well explored. For MOFs to realize their full potential as a solution to real-world problems, it is critical to develop effective strategies which are cost effective and feasible to be adapted for industrial use. In this thesis, I will explore efficient MOF synthetic methodologies and processing techniques, with the aim towards the eventual goal of MOF commercialization. In chapter 1, a broad overview of MOFs will be introduced. An extensive literature review exploring the current state of MOF research will be presented. Specifically, progress on large-scale MOF synthesis and their subsequent processing into functional materials will be discussed in detail. At the end of the chapter, opportunities for MOF research towards industrialization and commercialization will be highlighted and the thesis objective will be defined. After which, in chapter 2, a facile synthetic methodology which eliminates the use of HF and solvent to produce flexible chromium-based MOFs will be discussed. Using this methodology, 2 different isomorphous flexible MOFs can be obtained selectively, depending on the type of metallic salt used. This improved green synthetic procedure could be adapted for the large-scale preparation of these flexible MOFs in the future. Then, in chapter 3, a facile and efficient strategy to embed MOF powder onto fabric substrates using a poly(acrylic acid) binder will be introduced. This process minimizes waste production and can be applied to different types of MOFs and fabric substrates. The prepared MOF-fabric composites can be used for the industrial production of functional protective wearables against microbial activities. Following that, in chapter 4, the development of a gram-scale synthesis for archetypical ZIF-8 MOF and its subsequent processing into fabric substrate will be described. This procedure allows for low temperature, instantaneous production of ZIF-8 in high yield. The prepared ZIF-8 was also easily coated onto fabric substrates using poly(styrene) as a binder. The resultant composite was shown to be effective in dye adsorption and possess anti-bacterial properties. Lastly, in chapter 5, a summary concluding the various projects, which constitute this thesis, will be presented. A brief outlook of the future for MOF industrialization will also be discussed. Through various methods of producing and processing MOF material discussed in this dissertation, I hope to bridge the gap between scientific research and industrial needs, to truly develop MOFs into useful and functional materials for the future.