Electrospun Al-MOF fibers as D4 Siloxane adsorbent: Synthesis, environmental impacts, and adsorption behavior

Abstract

Here, we unveil the great potential of metal-organic framework (MOF) composite fibers produced by the electrospinning method to remove D4 siloxane from gaseous solutions. The fibers are based on polyacrylonitrile (PAN) and a microporous aluminum-based MOF known as DUT-4. The electrospinning configuration and DUT-4:PAN ratio in the precursor solutions play an important role in the textural properties of the fibers. Characterizations of morphology and textural properties demonstrated that the best dispersion on the fiber surface was achieved using coaxial electrospinning with a relationship of 1:1.4 of DUT-4:PAN. The Al-MOF fiber composite was evaluated as a D4 siloxane adsorbent, reaching over 85% of the D4 siloxane uptake capacity of individual DUT-4 crystals but with faster adsorption kinetics (effective diffusion coefficient 3.31 times higher). In addition, the synthesis of the composite showed a lower environmental impact and better thermal stability than that observed for DUT-4. This work shows the novel DUT-4 fibers have an outstanding potential for siloxane removal from biogas streams.