Controllable Location of Inorganic Nanoparticles on Block Copolymer Self-Assembled Scaffolds by Tailoring the Entropy and Enthalpy Contributions

摘要

Precisely controlling the spatial location and alignment of functional nanoparticles (NPs) on polymeric scaffolds is of great importance to not only create novel nanostructures but also enhance the properties of the hybrid nanomaterials. Herein, we demonstrate a strategy of tailoring the entropic and enthalpic contributions to precisely position gold nanoparticles (AuNPs) on block copolymer (BCP) scaffolds through the confined coassembly of BCPs and AuNPs within the emulsion droplet. According to this strategy, entropic effect arisen by the loss in conformational entropy and the enthalpic attraction between ligands on AuNPs and surfactants at the oil/water interface induce the solid AuNPs to move to the BCP surface, while the enthalpic interaction between the ligands on AuNPs and the corresponding polymer chains guides the AuNPs to position at the appropriate place. By this strategy, both the location and alignment of AuNPs on BCP scaffolds can be controlled at will, such as at the two terminals or along the lamellar boundary of the pupa-like scaffolds, or at the bases of pinecone-like or bud-like scaffolds, or at the head of one hemisphere, the entire hemisphere, or along the boundary between the two distinct hemispheres of the Janus-like scaffolds. We believe that this methodology can offer a universal route to achieve the precise positioning of functional NPs on the BCP scaffolds.