Search

A series of post-crosslinked resins were synthesized from macroporous chloromethylated styrene-divinylbenzene copolymer by controlling post-crosslinked reaction conditions. Adsorption study towards aniline showed that the three resins, ST-DVB-WH5, ST-DVB-WH6, and ST-DVB-WH7, prepared at different temperatures, and which had nearly identical static adsorption capacity, displayed great disparity in kinetic behavior. The rate constant of ST-DVB-WH7 by the pseudo-first-order model was 1.50 and 1.19 times higher than that of ST-DVB-WH5 and ST-DVB-ST-DVB-WH6. Further analysis of the diffusion model showed that the three resins exhibited different diffusion rates due to the difference in oxygen content and pore structure of each resin. The results showed that the adsorption capacity was mainly decided by the pore volume within 1.14 and 3.42 nm and the adsorption rate was mainly decided by the oxygen content of the resin. In addition, as the best synthetic resin for aniline adsorption, the equilibrium adsorption capacity of ST-DVB-WH7 was 1.57 times and 1.44 times higher than that of H-103 and NKA-II, respectively.

In the present study, a series of hypercrosslinked resins (CH series) was prepared in systematically designed conditions for the adsorption of nitroaromatics from aqueous solution. The newly synthesized CH-10 possesses a Brunauer–Emmett–Teller (BET) surface area up to 1,329.3 m2/g which is larger than that of the widely used hypercrosslinked resin H-103 and it exhibits great advantage over H-103 when subjected to nitrobenzene at low concentrations. The adsorption capacity of CH-10 for nitrobenzene is 1.4 times as much as that of H-103 at the concentration of 100 mg/L. Kinetic study by film diffusion model and intra-particle diffusion model revealed that its distinctive mesoporous structure within pore diameters between 2 and 6 nm played significant role in the mass transfer at low concentrations, and these unique mesopores also resulted in better adsorption capacity, which was confirmed by adsorption thermodynamics study. Moreover, the CH series displayed a good affinity to a wide scope of nitroaromatics and exhibited excellent dynamic adsorption and desorption properties in fixed bed.