In-situ synthesis of Metal Organic Frameworks (MOFs)-PA12 powders and their laser sintering into hierarchical porous lattice structures

This paper demonstrates the utilisation of in-situ synthesised novel metal organic framework (MOF)-polymer nanocomposite laser-sintered parts with enhanced CO₂ adsorption properties. Making use of polyamide PA12, one of the most common materials in powder bed fusion process as the base polymer, an in-situ synthesis of nanofiller ZIF-67 crystals on the surface of polyamide polymer particles was proposed to allow the fabrication of a nanocomposite powder with a good dispersion, reducing any health and safety handling issue arising from use of loose nanoparticles. This in-situ synthesis method allowed a maximum exposure of the ZIF-67 nano-porous sites. Laser sintering was used to fabricate porous structures with additional macro-pores and controlled cavities to increase the surface area. The laser-sintered ZIF67-PA12 part at only 2.6% wt ZIF-67 concentration exhibited a CO₂ capacity of 3.02 and 4.89 cm³/g at 298 K and 273 K at 1 bar. This in-situ synthesis method of making ZIF67-PA12 powders combined with the design freedom and the ease of fabrication of parts opens opportunities in a wider range of applications for MOFs such as energy storage and conversion.