Hydrothermal Synthesis of MOF. MIL-96 was synthesized according to the original method described previously whereas the protocol for polymer addition was adapted from another study. A typical hydrothermal synthesis solution contains Al(NO3)3.9H2O (1.3 g, 3.5 mmol), TMA (0.1 g, 0.5 mmol) and H2O (5 mL, 278 mmol) in a 23 ml Teflon liner. Firstly, to induce particle aggregation, HPAM solution (1000 mg/L) was poured into the reacting solution containing only the dissolved linker in H2O. The solution was later sonicated for 15 minutes prior to adding the metal precursor. The ratio between the volume of polymer solutions added to the volume of water (R) is defined below. The mixture was heated to 210 °C for 24 hours. After cooling to ambient conditions, the resulting solid product was recovered via filtration and consequently washed with copious amount of H2O. The washed residue was dried at 120 °C in vacuo overnight. Similar steps were implemented when using other polymer solutions (PAM and Na-PAA). Chemical structures for all the polymers are illustrated in Figure of the Supporting Information (SI).