A simple technique to recreate Swiss-cheese-like nanomaterials has been developed by researchers at KAUST. This material, and the method needed to make it, could help create more advanced materials with applications in photocatalysis and optoelectronics.
Porous materials are solids of low density and these voids give the porous material a large surface area, which is ideal for adsorbing other chemicals and acting as an improved catalyst for chemical reactions.
Porous organic polymers, or POPs, have shown particular promise for these applications due to their high porosity and their chemical and thermal stability, as well as the flexibility to capture specific target molecules and sustain a chemical response to enhance selective reactions.
Kafer Yaouz and his colleagues at KAUST, along with colleagues from Korea and the United States, have demonstrated a simple „one-pot” catalyst-free process for producing a highly porous POP called poly(aryl thioether). „We have shown that polyarylthioethers can be easily produced from sodium sulfide and perfluorinated aromatics,” says Yausz.
„We believe we have discovered a powerful strategy that defies common understanding and can be used to develop sulfur-based materials in a tunable fashion.” Their works have been published in journals Applied Chemistry International Edition.
Poly(aryl thioether)s are composed of perfluorinated aromatic compounds linked by sulfur linkers. One of the challenges in reproducing the material is that sodium sulfide can react with perfluorinated aromatic compounds at some of the different atomic sites.
Yavuz and team made their poly(aryl thioether) using a technique called polycondensation. They show that by careful temperature control, it is possible to ensure that a particular atom forms bonds over other potential atoms. This prevented uneven cross-linking and enabled a greater degree of control over the porosity of the material.
They demonstrated that the resulting microscopic organic polymer had a pore size of less than one nanometer and exhibited a high surface area of up to 753 square meters per gram of material. The team was able to demonstrate the material’s utility by removing organic micropollutants and toxic mercury ions from water.
„We now want to produce large-scale modules and offer these new micromaterials for electronic or photocatalytic applications,” says Yausz. For this we will work with electronics sector and water treatment facilities.
More information:
Doyun Kim et al., Covalent Scrambling in Porous Polyarylthioethers with a Stepwise SNR for Tunable Bandgap and Porosity, Applied Chemistry International Edition (2023) DOI: 10.1002/anie.202304378