Responsive Hybrid Nanotubes Composed of Block Copolymer and Gold Nanoparticles

Abstract

We demonstrate the facile fabrication of high aspect ratio nanotubes from responsive block copolymer, polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP), and in situ grown gold nanoparticles. PS-b-P2VP nanotubes are fabricated by template-assisted assembly by utilizing cylindrical pores of porous alumina membranes followed by its dissolution. Solvent annealing was employed to facilitate ordered phase separation of the block copolymer with in the nanotube structure, followed by in situ formation of gold nanoparticles in the P2VP domains occupying the inner and outer shell of the nanotubes. Owing to the pH-sensitive nature of P2VP block, which exhibits a coil to globule transition above pH 3.6, the PS-b-P2VP-gold nanoparticles hybrid nanotubes show reversible changes in topology, size (up to 25%), and collective plasmon resonance appearance. We suggest that PS-b-P2VP-gold nanoparticles hybrid nanotubes with their pH-responsive properties, large surface-to-volume ratio, and through open pore can find intriguing applications in sensing and microfluidic systems.

Smart surfaces with switchable superoleophilicity and superoleophobicity in aqueous media: toward controllable oil/water separation

“…[34][35][36] The X-ray photoelectron spectroscopy measurement of the functionalized textile indicated that the grafting of the block copolymer on the surface of the textile was achieved via a very small number of 2-vinylpyridine monomer units, and most of the pyridyl groups on P2VP-b-PDMS copolymer remained unchanged during the grafting process, which preserved the pH-responsive property of P2VP (Supplementary Figure S1). CA measurements were first conducted in air to probe the responsive wettability of the functionalized textile surface by using water droplets with different pH (Supplementary Figure S2).…”

“…As a weak polybase, P2VP has a pK a of about 3.6. 34 When in contact with a water droplet with a pH of 6.5, P2VP is therefore in the deprotonated state and exhibits a collapsed conformation due to the hydrophobic interaction between the deprotonated P2VP chains. On the other hand, the PDMS block has a desirably low glass transition temperature (Tg) of about À62 1C (according to the supplier), and it can be considered as a liquid-like polymer with high flexibility at ambient temperature.…”

Remotely Controllable Liquid Marbles

“…As has been reported, owing to its pH-responsive property, P2VP can alter its wettability as well as its conformation by protonation and deprotonation of its pyridyl groups in response to pH changes,26, 28, 29 and thus the grafted BCP endows the core/shell-structured particles with a pH-responsive property. Dynamic light scattering (DLS) and zeta potential measurements were first employed to characterize the pH-responsive property of the as-prepared RMPs in water with different pH values.…”

Selective and Sequential Re‐Assembly of Patterned Block Copolymer Thin Film for Fabricating Polymeric, Inorganic, and Their Composite Nanostructured Arrays

“…[6] For example, pH-responsive nanotubes composed of gold nanoparticles--polystyrene-block-poly(2-vinylpyridine) (PSb-P2VP), which were fabricated by template-assisted assembly with cylindrical porous alumina membranes followed by its dissolution, exhibited a reversible change in the plasmon resonance position which is extremely beneficial in microfluidics and biosensing. [7] Patterned nanomaterials with different structures have attracted much research attentions due to their unique properties and wide applications. Different nanostructures, such as wires, rods, tubes, particles, flowers made from polymeric, metals, ceramics, composites, etc.…”