Preparation of highly porous hypercrosslinked polystyrene adsorbents: Effects of hydrophilicity on the adsorption and microwave-assisted desorption behavior toward benzene

• Sulfonated hypercrosslinked polymer adsorbents were successfully prepared.
• The polymer adsorbents were predominantly microporous.
• Sulfonation led to only a slight reduction in the surface area and pore volume.
• Sulfonation significantly enhanced microwave-assisted desorption.
• The enhancement in desorption was due to the dielectric heating of adsorbed water.

In this study, highly porous hypercrosslinked polystyrene adsorbents were synthesized and subsequently sulfonated so as to make them more hydrophilic. All of the adsorbents were predominantly microporous and partially mesoporous. After sulfonation, the specific surface area and pore volume decreased to some degree, but were still within an acceptable range. The adsorption and microwave-assisted desorption behavior of the adsorbents toward benzene was investigated under humidified conditions. Compared to the as-synthesized adsorbents, the sulfonated adsorbents showed reduced adsorption capacities, but improved desorption efficiencies during a semi-continuous 600 W microwave irradiation process. The increased desorption efficiency was mainly attributed to a larger amount of adsorbed water, which indirectly allowed heating of the polymer adsorbents to higher temperatures upon microwave irradiation.

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