Ultrahigh Density Array of Free-Standing Poly(3-hexylthiophene) Nanotubes on Conducting Substrates via Solution Wetting

An ultrahigh density array of vertically and laterally aligned poly(3-hexylthiophene) (P3HT) nanotubes on conducting substrates was successfully fabricated by solution wetting in the anodized aluminum oxide (AAO) template. After solvent annealing, the conductivity of P3HT nanotubes was significantly increased due to highly aligned P3HT chains along the nanotube direction (or perpendicular to the substrate). This approach also provides a facile route for the preparation of ultrahigh density array of various conjugated polymer nanotubes. The conducting polymer nanotube array could be used for high performance organic devices, such as sensors, organic photovoltaic cells, and electrochromic devices

Hierarchically Well-Ordered Array of Concentric Silver Nanorings for Highly Sensitive Surface-Enhanced Raman Scattering Substrate

We fabricated a high density array of concentric silver nanorings in a large area (over in.²) with uniform gap distance by utilizing half onion-shaped microdomains prepared by symmetric polystyrene-<i>block</i>-poly­(methyl methacrylate) copolymers (PS-<i>b</i>-PMMA) confined within hemispherical cavities in anodized aluminum oxide (AAO) template. Silver nanoparticles with 6 nm height were selectively deposited only on the PS microdomains by thermal evaporation. The gap distance of two neighboring silver nanorings was controlled from 12 to 24 nm by changing the total molecular weight of PS-<i>b</i>-PMMAs. The substrate showed high surface-enhanced Raman scattering (SERS) enhancement factor as high as 4.3 × 10⁷ with good reproducibility (±7%). It could be used for biosensing, detection of trace-level explosive and hazardous chemicals, and reaction monitoring