Remazol red dye removal using poly (acrylamide-co-acrylic acid) hydrogels and wáter absorbency studies. Colloid and polymer science.

Corona-Rivera Miguel A., Bernal-Jácome Luis Armando, Ovando-Medina Víctor M., Cervantes-González Elsa, Dávila-Guzmán n.,Antonio-Carmona I.
Colloid and polymer science. 1(295) pp227-236., 2017.


Acrylamide (AAm) and acrylic acid (AAc) were copolymerized in aqueous solution using 2,2-azobis(2amidinopropane) hydrochloride (V-50) as initiator and N,N?methylenebisacrylamide (NMBAM) as cross-linking agent to obtain high swelling hydrogels. The effects of AAm/AAc ratio and the amount of cross-linking agent on the swelling properties were studied. It was observed that swelling characteristics of hydrogels are highly affected by the presence of carboxylic groups of AAc units in the hydrogels and by the cross-linking amount in the polymer chains. Hydrogel with 70/30ratioofAAm/AAcshowedthehighestswellingdegree, until 69.2 g of water/g of dried hydrogel, which represents approximately 7000% of swelling. Swelling kinetic was well represented by a second-order kinetic model for all the AAm/ AAc compositions with maximum weight swelling ratio between20.4and82.6g/gforthehydrogelssynthesizedusing 1%ofNMBAM.Diffusionbehavioranalysesdeterminedthat water diffusion into hydrogels followed the anomalous Fickian behavior. The as synthesized hydrogels were used in theremovalofRemazolRed3BS(RR3BS)dyefromaqueous solutions, finding that the maximum dye adsorption capacity for an equilibrium aqueous concentration of 130 mg/L of RR3BS was 44.19 mg of RR3BS/g of dried hydrogel with 1% of NMBAM, with an adsorption mechanism well represented by the Langmuir model. Keywords Hydrogel .Acrylamide .Acrylicacid .Remazol reddye .Waterdiffusion