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Studies of absorption of metals and its recovery in hydrogels obtained from poly(acrylamide) and biopolymers (chitosan and polyhydroxyalkanoates)

Abstract:

In this paper we present the results of semi-interpenetrating (semi-IPNs) hydrogels (HG) of poly (acrylamide)/chitosan and poly(acrylamide)/poly (hydroxyalkanoates). The maximum hydration degree reached by the semi-IPN poly(acrylamide)/chitosan HG as compared with polyacrylamide hydrogel showed that the presence of chitosan (Q) occluded in its network expansion favored greater swelling degrees. Similar results were obtained when the synthesis was made with the biopolymer PHB, poly (hydroxybutyrate) in poly(acrylamide)/PHB hydrogels. However, when in the HG synthesis were feed 10 and 20% of P(HB-co-HV), poly (hydroxybutyrate-co-hydroxyvalerate), were generated gels of poly (acrylamide)/P (HB-co-HV) with minor swelling degree. We compared their absorptive properties with semi-IPN poly(acrylamide)/poly (acrylic acid), PAAm/PAAc and poly (acrylamide-co-acrylic acid) AAm-co-Aac hydrogels. The results suggest that, at least when low proportions of biopolymer Q or PHB was feed, increases the expansion of the network in the semi-IPN by adding the biopolymer. However, analyzes performed by optical emission spectrometry and inductively coupled plasma (ICP-OES) demonstrated that the interaction of these HG with metal ions was weak as compared to copolymers of hydrogels AAm-co-AAc and the semi-IPN PAAm/PAAc. But it was shown that subsequent recovery of the elements in a solution of HNO3 is effective. © 2012 Universidad Simón Bolívar.