PREPARATION OF TYPE 2 AND TYPE 3 POROUS LIQUIDS
FOR THE ABSORPTION OF VOLATILE ORGANIC
COMPOUNDS

Abstract

Porous materials have been widely used in various applications from gas capture to
electrochemistry. So far, the utilised materials have been of solid phase. However, it has been
established that liquid phase materials are more efficient in industrial settings. Thus,
engineering accessible porosity into the liquid phase can result in highly efficient and soughtafter materials.
The aim of this work was to prepare Type 2 and Type 3 porous liquids for the capture
of volatile organic compounds. For the former, dimeric and hexameric nanocapsules were
selected due to their relatively small cavity window sizes, which would allow for the
encapsulation of small VOCs, yet prevent the entrance of larger solvent molecules. To
prepare Type 3 porous liquids, a commercially available Basolite® F300 MOF was selected
due to its well-defined pore size and thermal stability. Two types of ionic liquid were
employed: imidazolium- and phosphonium-based ionic liquids. Due to the unknown
solubility of the porous solids, it was desirable to select both types of IL.
Type 2 porous liquids were not successfully prepared. This was due to the presence
of solvent molecules within the cavities of the nanocapsules as evidenced via mass
spectrometry and NMR spectroscopy and single crystal X-ray diffraction. NMR results
showed that the Zn-PgC3 nanocapsule was incapable of guest exchange. Thus, these
nanocapsules were not used for the preparation of Type 2 porous liquids.
On the other hand, stable colloids of Basolite® F300 with the phosphonium-based
ILs were prepared. To characterise the presence of empty pores within these colloids, a
biphasic dye extraction setup was used and analysed with UV-Vis spectroscopy. The results
show that PL2 does not possess superior dye absorption capabilities compared to its ionic
liquid counterpart, indicating that there is no intrinsic porosity within these porous liquids,
or that it does not affect dye absorption.