As synthesized TBAP was fully dissolved 2 M KOH (aq.). The aq. solution was then placed in an ice bath for 10 minutes, and excess concentrated HCl (aq.) was added in one portion to neutralize the solution and rapidly precipitate the TBAP material. The TBAP material was collected by filtration and washed with copious amounts of water. The filtrate was then suspended in water (20 mL), sonicated for 1 hour, and re-filtered to ensure all remaining salts were washed out. This process was repeated three times in total. The amorphous TBAP sample was dried under vacuum at 120 °C and a PXRD pattern of the amorphous material was recorded, see