Rapid Synthesis of Metal-Organic Frameworks in Novel Reaction Media
Metal Organic Frameworks (MOFs) are porous materials that have attracted a great deal of attention in the past two decades due to their adaptable structures and pore size and their applicability across a broad range of fields including in catalysis, chemical separation and storage, including gases and liquid fuels, chemical sensors, magnetism, ion exchange, nonlinear optics, MRI imaging and also in biology and the biomedical fields. This technology is based on microwave synthesis of MOFs in a proprietary reaction media that encourages formation of MOFs with advantageous qualities compared to conventional reaction media.
The essence of this technology is a novel reaction media that provides a mechanism for fast and nontoxic synthesis of MOFs in the presence of microwave radiation. By comparison, most conventional methods for microwave synthesis of MOFs are slow and require the use of toxic solvents. MOFs have been synthesized using many techniques including: slow evaporation, diffusion, direct mixing, solvothermal, ionothermal, sonochemical, mechanochemical, electrochemical, microwave, microfluidic synthesis, and dry-gel conversion. Many of these synthetic methods involve the use of structurally directing solvents such as: DMF, DEF, and DMA, which are problematic because these volatile organic compounds are carcinogens and can cause significant environmental pollution at an industrial scale. Ionic liquids (ILs), salts that are liquid below 100ºC, have also been successfully used to synthesize MOFs, but many ILs are expensive, corrosive and their toxicity to human health and environment is not well established.
In addition, microwave irradiation has been shown to typically produce microcrystalline products, as opposed to large single crystals that often results from oven or autoclave synthesis, and these microcrystalline MOFs have demonstrated improved catalytic ability. Microwave synthesis is also an attractive alternative to oven and autoclave synthesis because it often reduces the synthesis times from days to minutes or hours. Further exploration of the advantageous characteristics and qualities of MOFs created by microwave synthesis using the proprietary reaction media is required.