Frontal polymerization preparation of poly(acrylamide-co-acrylic acid)/activated carbon composite hydrogels for dye removal

A series of poly(acrylic acid-co-acrylamide) (PAA)/activated carbon (AC) composite hydrogels were rapidly prepared via frontal polymerization (FP). It was found that an increase in the concentration of AC caused an increase in the front velocity (Vf) and the highest front temperature (Tmax). It may be attributed to that AC particles could increase the liquid viscosity of reaction mixture and remain the reaction heat during FP. The Fourier transform infrared and scanning electron microscopy (SEM) confirmed that AC particles had entered the hydrogel network, and many spherical AC particles with an average diameter of 0.5-1 m had been dispersed homogeneously in the PAA hydrogel matrix. The swelling behavior showed that the equilibrium swelling values of hydrogels increased when the concentration of AC particles increased. Adsorption studies showed that incorporation of AC particles into PAA hydrogel matrix could increase the sites of interaction between the hydrogels and crystal violet molecules and result in an increase of adsorption capacities of hydrogels toward dyes. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013