Preferential Self-Assembly of Surface-Modified Si/SiOx Nanoparticles on UV/Ozone Micropatterned Poly(dimethylsiloxane) Films

Abstract

The specific self‐assembly of Si/SiOx core–shell nanoparticles onto UV/ozone micropatterned poly(dimethylsiloxane) (PDMS) films is reported here. Auger and Raman spectroscopic mapping document the preferential Si/SiOx nanoparticle adsorption within PDMS domains (see Figure). These nanoparticles display a high refractive index, which renders them potentially important for photonic bandgap applications.

Chemical Reduction and Dimerization of 1‐Chloro‐2,3,4,5‐tetraphenylborole

“…Other methods have been employed for directed self‐assembly, including surface templating2, 3, 29 and adaptations of photolithography 30, 31. However, the surface templating employs conventional lithographic or micromachining methods for patterning specific features onto the surface.…”

“…Exquisite control is possible, but this approach becomes complicated and very expensive as the size scale decreases. The “bottom‐up” strategy creates structures from smaller subunits through thermodynamically driven self‐assembly, and has been employed with diverse objects such as nanotubes,1 nanoparticles for synthesis of photonic bandgap crystals,2, 3 antibodies on gold surface for immunosensing,4 and miniature electrical components (solder dots, wires, dies, and diodes) for electrical networks 5, 6. Cost is greatly reduced, but reliable control over patterning remains problematic due to entropy effects that become prominent at small length scales.…”

Organic-Inorganic Nanohybridization by Block Copolymer Thin Films

“…It is known that free radicals and activated species, which have been generated in situ from atmospheric oxygen by UV light, remove organic polymer. [42,57,58] Figure 6A clearly shows that highly dense arrays of titania dots were generated over the wide area of the surface, keeping the lateral positional and orientational order. The height of the dots estimated from the side view (Fig.…”

Biochips: non-conventional strategies for biosensing elements immobilization

“…Once polymerized, PDMS reveals a very hydrophobic surface due to methyl groups beard by the Si atoms of the polymer chain, and this lack of functional groups restrains covalent immobilization of biomolecules. Oxygen plasma treatment is to date the most widespread technique used to convert the methyl groups into hydroxyl ones rendering the surface reactive and hydrophilic (19), but UV-light irradiation (at 184 nanometers and 254 nanometers) (20) or ozone production using a corona discharge have also been used (21). Nevertheless, this modification is only temporary since un-polymerized buried chain could migrate to the surface, leading to the recovery of the PDMS hydrophobic property (22).…”