Synthetic modification of silica coated magnetite cored PAMAM dendrimer to enrich branched Amine groups and peripheral carboxyl groups for environmental remediation

Abstract

Dendrimer with amine groups have several applications in gene delivery, drug delivery, metal encapsulation for catalysis and environmental remediation. Specifically, dendrimers having enriched amino groups with accessible void makes significant impact in the above fields. Besides, the carboxylic acid terminated amine dendrimers may enhance the efficacy as well. Therefore, herein we report the synthetic modification of poly(amidoamine) G3 dendrimer with magnetite core to enrich branched amine groups and peripheral carboxyl groups. To deliver this nanohybrid material, for the first-time silica coated magnetite cored poly(amidoamine) G3 dendrimer was synthesized by microwave assisted method. Subsequently amide groups present in the PAMAM have been reduced using lithium aluminum hydride to yield polyamine dendrimer namely poly (N-propylethane-1,2-diamine) G3. Further, peripheral amine groups were grafted with succinic anhydride to achieve carboxylic acid terminated dendrimer. The resulting nanomaterial was confirmed by FTIR, XRD, VSM, TGA, HRTEM and conductometry methods. In order to emphasize the structural efficacy of polyamine dendrimer, the metal ion uptake behavior has been discussed for the representative cations such as Pb2+, Cu 2+, Cr6+, Ca2+ and Ni2+ under the environmental concern. Magnetite cored polyamine dendrimer had evaluated for its recyclability test in the subsequent metal ion uptake studies and found to be satisfactory.