PLVPs were synthesized according to the approach shown in Scheme 1 by using free radical polymerization (FRP). The detailed description of synthesis can be found in the Experimental Section. To ensure that the prepared polymer is free of any chromophore, azobis(isobutyronitrile) (AIBN) was employed as the initiator. The obtained polymers were further purified by precipitation of its solution three times in hexane. After drying in a vacuum oven at 75 °C overnight, a white powder was obtained.