Multifunctional Organic-Inorganic Nanocomposites with Unprecedented Control Over Dimensions, Compositions and Architectures as Well as Tailored Properties
Abstract
Over the past year, we have developed several robust strategies for crafting stable hairy nanoparticles (NPs). First, we report in-situ crafting of noble metal NPs (i.e., Au) intimately and permanently ligated by thermoresponsive polymers (i.e., poly (Nisopropylacrylamide); PNIPAM) using double-hydrophilic star-like block copolymer as nanoreactor to resolve the paradox noted above. The strongly ligated PNIPAM on the Au NP surface effectively eliminate the inevitable ligand dissociation issue due to the dynamic binding nature of ligands as in copious past work. As such, two seemingly contradictory observations on both temperature-dependent optical and catalytic properties largely encountered in the literature are elucidated by capitalizing on judiciously designed thermoresponsive PNIPAM-capped Au NP system. Intriguingly, as temperature increases over the lower critical solution temperature (LCST) of PNIPAM, plasmonic absorption peak of PNIPAM-capped Au NPs redshifts accompanied by an increase in intensity in the absence of free linear PNIPAM, whereas the characteristic absorption peak red-shifts greatly with a decreased intensity in the presence of deliberately introduced linear PNIPAM. Moreover, remarkably, the absence or addition of free linear PNIPAM also accounts for a non-monotonic (i.e., non-Arrhenius) or a switchable 'on/off' catalytic performance of PNIPAM-capped Au NPs, respectively. The star-like block copolymer nanoreactor strategy is robust and enables the convenient creation of a rich diversity of new hybrid materials composed of functional NPs (e.g., Ag, TiO2, SiO2, Fe3O4, and BaTiO3) permanently tethered with polymers of interest, thereby underpinning future advances in optics, optoelectronics, catalysis, medical imaging and therapy, nanotechnology, and biotechnology. Second, we also demonstrated a general amphiphilic star-like block copolymer nanoreactor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 19, 2019
- Accession Number
- AD1086108
Entities
People
- Zhiqun Lin
Organizations
- Georgia Tech Research Corporation