Grantee Research Project Results

Dendritic Nanoscale Chelating Agents: Synthesis, Characterization, Molecular Modeling and Environmental Applications

EPA Grant Number: R829626
Title: Dendritic Nanoscale Chelating Agents: Synthesis, Characterization, Molecular Modeling and Environmental Applications
Investigators: Diallo, Mamadou S. , Goddard, William A. , Johnson, James H. , Balogh, Lajos
Institution: Howard University , University of Michigan , California Institute of Technology
Current Institution: California Institute of Technology , Howard University , University of Michigan
EPA Project Officer: Hahn, Intaek
Project Period: May 1, 2002 through April 30, 2005
Project Amount: $400,000
RFA: Exploratory Research: Nanotechnology (2001) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Nanotechnology , Safer Chemicals

Description:

Dendrimers are monodisperse and highly branched nanostructures with controlled composition and architecture. Poly(amidoamine) (PAMAM) dendrimers possess functional nitrogen and amide groups arranged in regular "branched upon branched" patterns. This high density of nitrogen ligands enclosed within a nanoscale container makes PAMAM dendrimers particularly attractive as high capacity chelating agents for toxic metal ions [Cu(II)], electron transfer mediators [Fe(II)], redox active metal clusters [FeS] and metal clusters with catalytic properties [Pt (II)]. PAMAM dendrimers can also be functionalized with surface groups that make them soluble in appropriate media or bind onto appropriate surfaces. This project explores the fundamental science of metal ion uptake by PAMAM dendrimers in aqueous solutions and assesses the extent to which this fundamental knowledge can be used to develop:

high capacity and reusable chelating agents for industrial and environmental separations; and
FeS laden nanoparticles with enhanced reactivity, selectivity and longevity for reductive detoxification of PCE in aqueous solutions and subsurface formations.

Approach:

To achieve these objectives, we propose an integrated project that combines: 1) materials synthesis and characterization; 2) bench scale measurements of metal ion [Cu(II), Fe(II), Co(II), Ni(II), Cd(II) and Ag(I)] uptake by PAMAM dendrimers in aqueous solutions; 3) X-ray absorption spectroscopic (XAS) investigations of metal ion-PAMAM dendrimer complexes in aqueous solutions; 4) bench scale measurements and spectroscopic investigations of the reduction of PCE by water soluble FeS-PAMAM dendrimer nanocomposites and solid particles coated with FeS-PAMAM dendrimer nanocomposites; and 5) molecular modeling of (i) metal ion uptake by PAMAM dendrimers in aqueous solutions and (ii) PCE reductive dechlorination by FeS clusters.

Expected Results:

The successful completion of this research is expected to result in 1) more effective functional materials for recovering precious metal ions [e.g., Ag (I)] and toxic metal ions [e.g., Cu (II)] from industrial wastewater solutions by low cost membrane based processes [e.g., ultrafiltration], and 2) more effective reactive media for reductive detoxification of PCE in aqueous solutions and subsurface formations.

Publications and Presentations:

Publications have been submitted on this project: View all 41 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 7 journal articles for this project

Supplemental Keywords:

water, soil, heavy metals, DNAPL, nanotechnology, waste reduction, waste minimization, pollution prevention, environmental chemistry and modeling., Sustainable Industry/Business, RFA, Scientific Discipline, Water, Technology for Sustainable Environment, Ecological Risk Assessment, Civil/Environmental Engineering, Sustainable Environment, Environmental Chemistry, Engineering, Chemistry, & Physics, Chemistry and Materials Science, Biochemistry, New/Innovative technologies, Environmental Engineering, sustainability, dendrimers, detoxification, membrane technology, membranes, innovative technologies, environmental sustainability, membrane filtration, industrial wastewater, environmentally applicable nanoparticles, ultrafiltration system, nanotechnology, groundwater, PCE, membrane-based, reductive detoxification, innovative technology

Progress and Final Reports:

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.