High-Temperature Melt Stamping of Polymers Using Polymer/Nanoporous Gold Composite Stamps.

Parallel lithographic deposition of polymers onto counterpart substrates is a widely applied surface manufacturing operation. However, polymers may only be soluble in organic solvents or are insoluble at all. Solvent evaporation during stamping may trigger hardly controllable capillarity-driven flow processes or phase separation, and polymer solutions may spread on the counterpart substrates.

Manipulating Semicrystalline Polymers in Confinement.

Because final properties of nanoscale polymeric structures are largely determined by the solid-state microstructure of the confined polymer, it is imperative not only to understand how the microstructure of polymers develops under nanoscale confinement but also to establish means to manipulate it. Here we present a series of processing strategies, adapted from methods used in bulk polymer processing, that allow us to control the solidification of polymer nanostructures. First, we show that supramolecular nucleating agents can be readily used to modify the crystallization kinetics of confined poly(vinylidene fluoride) (PVDF).

Honeycombs in honeycombs: complex liquid crystal alumina composite mesostructures.

Small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM) were used to study orientation patterns of two polyphilic liquid crystals (LC) confined to cylindrical pores of anodic aluminum oxide (AAO). The hierarchical hybrid systems had the LC honeycomb (lattice parameter 3.5-4 nm) inside the pores of the AAO honeycomb (diameters 60 and 400 nm).

Formation of straight 10 nm diameter silicon nanopores in gold decorated silicon.

We observe pore formation with diameters in the 10 nm range in silicon when it is covered with gold particles. This pore etching occurs when the sample is put in 5 wt % hydrofluoric acid (HF) solution for a few minutes. The pores form along the 100 direction, which is also the preferred direction of macro- and mesopores electrochemically etched into silicon.