Macroporous PDVB microspheres (3.02 g) with diameter of
350–450m and dichloromethane (75.0 mL) were added into a
250mL three-neck bottle. The solution was cooled to 0 ◦C in an
ice bath, before another 75.0 dichloromethane containing 0.8mL
chlorosulfuric acid was dropwise added into the stirred solution.
Then, the reaction was performed at room temperature for 24 h
with magnetic stirring. The sulfonated products were filtrated
by a sintered glass funnel, and washed by dichloromethane for
three times. After dried in a vacuum oven, the sulfonated microspheres
were washed with deionized water for five times, and
dried in vacuum oven. The sulfonated microspheres were marked
as PDVB–SO3H.