Fabrication of functional block copolymer particle by precise control of nanoparticle location

Abstract

Precise positioning of nanoparticles(NPs) with desired inter-spacing can produce novel optical and electrical properties. Here, we developed functional block copolymer (BCP) particles of polystyrene-b-poly(4-vinylpyridine) (PS-P4VP) by precise control of nanoparticle location inside the BCP particles. Multi-color emitting hybrid BCP-QD particles with three-dimensionally controlled nanostructures were developed through location control of different-colored QDs in BCP micelles. Hydrogen interaction assisted method using supramolecular assembly of BCP micelles was exploited to achieve the location control of different colored QDs without sacrificing any quantum yield efficiency. The spatially controlled, independent light emissions from our QD-encoded particles could be beneficial for use in applications such as security inks for anti-counterfeit, bio-imaging and conducting bioassays by targeting biomarkers. In addition, a dramatic morpho-logical transition of BCP particles was driven by size-controlled Au NP surfactants. Size-induced segregation of Au NPs generated the balanced interfacial interaction between two different PS/P4VP domains of BCP particles and water, producing unique disk-like shape of BCP particles. More importantly, the neutralized interfacial interaction combined with the directionality of solvent induced solvent-induced ordering of BCP domains from the interface of the particle/water, generating defect-free, vertically ordered porous channels within the particles. The mechanism for the formation of these novel nanostructures was investigated systemically by varying the size and the volume fraction of Au NPs. Furthermore, the defect-free porous P4VP channels within the BCP particles can be successfully loaded with various nanoparticles or other materials which have selective affinity; thus these materials hold great promise for use in optical, catalytic, biological applications.