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Molecular-scale visualization of ligand conformation on functionalized nanoparticles: A combination of experimental and theoretical studies


EMSL Project ID
39891

Abstract

The goal of this project is to develop capabilities that will advance the fundamental understanding of the interaction between the nanoparticles surfaces and organic ligand molecules as applicable to dye-sensitized solar cells, contamination remediation in the ground water and drug delivery in the biological systems. This would be accomplished by using CeO2 nanoparticles and organic ligands with carboxylate and phosphonate functional groups, applying existing and newly developed tools at EMSL to characterize the nanoparticle-ligand interactions and by measuring the impact of the derivatives on the organic ligands, the variation of the surface potential of the nanoparticles surfaces and their particle sizes. The results on these systems will provide information about the structural and electronic aspects at molecular level, the chemical state of elements in the nanoparticle and organic coating, number of ligand molecules on the particle surface, their orientation and nature of packing. Mainly, the non-linear optical methods, sum frequency generation-vibrational spectroscopy (SFG-VS) and the second harmonic generation (SHG) will be used to characterize the functional groups and their conformation on the nanoparticle surfaces (the bonding sites, bond strength, and bond directions of ligand molecules on ceria nanoparticles) in addition to x-ray photoelectron spectroscopy, UV-Vis spectroscopy, and electron microscopy for physical and electronic structure information. First principle calculations will provide critical insights into the surface structure, the conformation of binding ligands, and the chemical nature of bonding interactions. The combined and complementary data sets from theoretical studies and experimental efforts will help us visualize and elucidate the, often complicated, nature of cerium oxide nanoparticle-ligand systems and help extend the understanding to other relevant systems in future. These efforts combining experimental measurements and theoretical studies to comprehensively understand the functionalized nanoparticles will enable a team poised to help address the issues of fundamental and applied interest in the area of nanoparticles’ research.

Project Details

Start Date
2010-04-01
End Date
2012-11-07
Status
Closed

Team

Principal Investigator

Theva Thevuthasan
Institution
Environmental Molecular Sciences Laboratory

Team Members

Weina Wang
Institution
Shaanxi Normal University

Hongfei Wang
Institution
Fudan University

Ping Yang
Institution
Los Alamos National Laboratory

Ajay Karakoti
Institution
Pacific Northwest National Laboratory

Satyanarayana Kuchibhatla
Institution
Battelle India

Ponnusamy Nachimuthu
Institution
Environmental Molecular Sciences Laboratory

Sudipta Seal
Institution
University of Central Florida

Chongmin Wang
Institution
Environmental Molecular Sciences Laboratory