Block Copolymer-Templated Au@CdSe Core-Satellite Nanostructures with Solvent-Dependent Optical Properties.

In the present work, we report the fabrication and characterization of well-defined core-satellite nanostructures. These nanostructures comprise block copolymer (BCP) micelles, containing a single gold nanoparticle (AuNP) in the core and multiple photoluminescent cadmium selenide (CdSe) quantum dots (QDs) attached to the micelle's coronal chains. The asymmetric polystyrene--poly(4-vinylpyridine) (PS--P4VP) BCP was employed to develop these core-satellite nanostructures in a series of P4VP-selective alcoholic solvents.

Silica-supported Au@hollow-SiO particles with outstanding catalytic activity prepared via block copolymer template approach.

Catalytically active Au@hollow-SiO particles embedded in porous silica support (Au@hollow-SiO@PSS) were prepared by using spherical micelles from poly(styrene)-block-poly(4-vinyl pyridine) block copolymer as a sacrificial template. Drastic increase of the shell porosity was observed after pyrolytic removal of polymeric template because the stretched poly(4-vinyl pyridine) chains interpenetrating with silica shell acted as an effective porogen. The embedding of Au@hollow-SiO particles in porous silica support prevented their fusion during pyrolysis.

Helical packing of nanoparticles confined in cylindrical domains of a self-assembled block copolymer structure.

Theoretical models predict that a variety of self-assembled structures of closely packed spherical particles may result when they are confined in a cylindrical domain. In the present work we demonstrate for the first time that the polymer-coated nanoparticles confined in the self-assembled cylindrical domains of a block copolymer pack in helical morphology, where we can isolate individual fibers filled with helically arranged nanoparticles. This finding provides unique possibilities for fundamental as well as application-oriented research in similar directions.

Control on molecular weight reduction of poly(ε-caprolactone) during melt spinning--a way to produce high strength biodegradable fibers.

Poly(ε-caprolactone) (PCL) is known for its biocompatibility and biodegradability. These features of PCL have resulted into significant academic as well as industrial research interests for use of this polymer in various areas including biomedical and tissue engineering. Three-dimensional porous scaffolds, controlled drug release systems and nerve guides are some of the forms in which this polymer has been used.