Research Descriptions

Green Catalysis: Colloidal Metal Nanoparticles for Selective and/or Multifunctional Chemical Transformations in Green Environments

Our research targets the preparation of ligand-capped metal nanoparticle catalysts that are soluble in water or greener organic solvents such as ethyl acetate, methyl ethyl ketone, and ethanol. The main objective is to investigate the effects of the surface density and structure/composition/conformation of thiolate ligands adsorbed on metal nanoparticle catalyst surfaces for regio-, chemo-, and/or stereoselective organic reactions. Our research group previously has shown that Pd nanoparticles exhibit a unique selectivity for organic reactions such as the isomerization of allylic alcohols and terminal alkenes and the selective hydrogenation of alkenes and dienes. Ionic or highly polar ligand-capped metal nanoparticles will allow selective chemical reactions to take place in green environments. In addition, by introducing another active functional group such as a basic tail in some organic ligands, nanoparticle catalysts can further act as tandem catalysts for multiple organic transformations.

[Funded by NIH-NIGMS]

Biocompatible Nanocatalysis: Lipid-Metal Nanoparticle Assemblies (LNAs) for Catalytic Reactions under Physiological Conditions

The development of a simple and safe way to detect and cure diseases has been considered a high-priority area in the field of biotechnology and medical research. Our research specifically targets the preparation of a biocompatible nanoparticle platform for potential therapeutic agents (pro-drug delivery and activation). The target nanocarriers are the lipid-nanoparticle assemblies (LNAs) such as carbohydrate-coated liposomes with bilayer-embedded nanoparticles and lipoprotein-encapsulated nanoparticles. Carbohydrates and proteins serve as cancer-specific targeting groups and will potentially guide LNAs to the tumor sites. Encapsulated metal nanoparticles act as activation catalysts for co-embedded pro-drug molecules. By introducing different hydrophobic functional groups in the “tail” of hydrocarbon chains of organic ligands, we can adjust both steric and non-covalent interactions in the near-surface environment in a manner analogous to changing amino acid residues (side groups) in an enzyme binding pocket.

[Funded by NSF - Chemical Catalysis]

Photocatalysis: Carbon Nanoparticles or Quantum Dot/Dye NanoHybrid Assemblies for Photo-Enhanced Chemical Reactions

Our research targets the preparation of hybrid nanoassemblies that are suitable for photocatalysis and energy applications. Photoactive materials such as carbon nanoparticle/quantum dots and laser dyes with unique physical and chemical properties are considered promising candidates for enhancing the absorption of photoenergy and catalytic efficiency of adjoining nanoparticulate materials. The controlled synthesis of metal nanoparticle-carbon quantum dot hybrid assemblies and laser dye-linked metal nanoparticles will allow the fundamental understanding of the influence of photoactive materials on the chemical and electronic properties of catalytic Pd nanoparticles. Additional research goals include fluorescent coatings suitable for sensing and electronic devices. This new project aims to develop the chemical methodology for the preparation of fluorescent silicone polymer by embedding a fluorescent tag to the material prior to cure.

[Funded by DOE-EFRC via UCI]