Grantee Research Project Results
2003 Progress Report: Dendritic Nanoscale Chelating Agents: Synthesis, Characterization, Molecular Modeling and Environmental Applications
EPA Grant Number: R829626Title: 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 Period Covered by this Report: May 1, 2003 through April 30, 2004
Project Amount: $400,000
RFA: Exploratory Research: Nanotechnology (2001) RFA Text | Recipients Lists
Research Category: Hazardous Waste/Remediation , Nanotechnology , Safer Chemicals
Objective:
Dendrimers are 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 [Pd(II)].
The objective of this research project is to explore the fundamental science of metal ion uptake by PAMAM dendrimers in aqueous solutions and assess the extent to which this fundamental knowledge can be used to develop:
- high capacity and reusable chelating agents for industrial and environmental separations;
- and iron sulfide (FeS) laden nanoparticles with enhanced reactivity, selectivity, and longevity for reductive detoxification of tetrachloroethylene (PCE) in aqueous solutions and subsurface formations.
Progress Summary:
During Year 2 of the project, we continued our measurements of metal ion binding [Co(II), Ni(II), Ag(I), and Fe(III)] to ethylene diamine core PAMAM dendrimers at Howard University (HU). The Principal Investigator (PI) of this project (Mamadou Diallo) and his group at HU also leveraged U.S. Environmental Protection Agency (EPA) funding to develop Dendrimer Enhanced Ultrafiltration (DEUF) for recovering metal ions from aqueous solutions. DEUF is a patented process that exploits the unique properties of dendritic polymers (e.g., dendrimers, dendrigraft polymers, and hyperbranched polymers) as high capacity and recyclable chelating agents. Co-PI Lajos Balogh and his group at the University of Michigan focused on the synthesis and characterization of FeS dendrimer nanocomposites in solutions, thin films, and mesoporous silica gels. The FeS nanoparticles were prepared using generation four PAMAM dendrimers with amine, hydroxyl, and succinamic acid terminal groups as templates. The ability of the FeS dendrimer nanocomposites (25 ppm of FeS) to reduce PCE (5 ppm) in aqueous solutions was evaluated at HU using gas chromatography with electron capture and flame ionization detectors. We found significant reduction of PCE (40-50% after 3 hours) with no production of tricholoroethylene in all cases.
Future Activities:
We will continue to leverage EPA funding to test the ability of DEUF to recover metal ions from membrane concentrates. We also will continue our measurements of the synthesis and evaluation of redox active FeS dendrimer nanocomposites using PCE as a model organic compound.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 41 publications | 10 publications in selected types | All 7 journal articles |
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Diallo MS, Christie S, Swaminathan P, Johnson Jr. JH, Goddard III WA. Dendrimer enhanced ultrafiltration. 1. Recovery of Cu(II) from aqueous solutions using PAMAM dendrimers with ethylene diamine core and terminal NH2 groups. Environmental Science & Technology 2005;39(5):1366-1377. |
R829626 (2002) R829626 (2003) R829626 (Final) |
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Diallo MS, Christie S, Swaminathan P, Balogh L, Shi X, Um W, Papelis C, Goddard III WA, Johnson Jr. JH. Dendritic chelating agents. 1. Cu(II) binding to ethylene diamine core poly(amidoamine) dendrimers in aqueous solutions. Langmuir 2004;20(7):2640-2651. |
R829626 (2002) R829626 (2003) R829626 (Final) |
Exit |
Supplemental Keywords:
polymer chemistry, materials chemistry, physical/theoretic chemistry, computational chemistry, molecular modeling, environmental chemistry, environmental engineering, chemical engineering, process engineering, environmental detoxification, groundwater remediation, pollution prevention, hazardous organics, industrial wastewater, membrane technology, polymer enhanced ultrafiltration, metal removal, nanocatalysts,, 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 technologyProgress and Final Reports:
Original AbstractThe 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.