Polystyrene ordered arrays

In order to investigate this effect, ordered arrays of metallic nano-islands were fabricated on glass substrates by a process of natural lithography using monodisperse polystyrene nanospheres. The metal particle dimensions were tailored in order to tune the plasmon resonance wavelength to match the spectral absorption of the fluorophore. The fluorophore, Cy5 dye, which is widely used in optical immunoassays and has a medium quantum efficiency ( 0.3), was used in this preliminary study of the plasmonic enhancement effect. 

Colloidal zeolites have been used as building blocks to fabricate hierarchical porous materials. Infiltrating ethanol sol of zeolite nanoparticles into an ordered array of polystyrene spheres resulted in macroporous zeolites, which involves a self-assembly process. After ethanol evaporation, zeolite nanoparticles were aggregated by capillary forces. High concentration of external silanol groups favored the formation of hydrogen bonds between particles and eventually Si-O-Si bonds after calcination. The method has been further developed to produce transparent and self-standing zeolite membranes with controlled mesoporosity. Concurrently, the preformed zeolite-coated polystyrene spheres have been... 

Polystyrene microspheres are deposited in a hexagonally ordered array... 

A sophisticated enhancement of metal vapor deposition involves silver deposition over an ordered array of polystyrene spheres with submicron diameters (41-43). The Ag atoms deposit both on the spheres and on the flat substrate below the spheres. After deposition, the spheres may be removed to leave an ordered array of microscopic Ag pyramids with regular size and shape. The pyramids have dimensions of a few hundred nanometers, in the range required for EM field enhancement. These arrays of Ag microparticles have provided a direct test of EM field enhancement theory (44), and have been modified with platinum and organic thin films (45). 

Recently, membranes with SP nanoparticles have been introduced which operate on a slightly different principle, as illustrated in Fig. 13.7. The membranes contain an ordered array of stimuli-responsive core-shell type magnetic polystyrene latex particles. The particles change their size in response to external stimuli, acting as on-off switches or permeability valves , regulating the permeation through membrane channels. 

The sol-gel method was widely used in the preparation of photonic materials and structures during the last decades. The design and preparation of hybrid nanocomposites for photonics are widely described in Refs [7,145-147]. The wide range of photonic structures prepared using the sol-gel method include colloidal crystals based on silica or polystyrene spherical particles [148,149], photonic crystals [150-152], photonic bandgap materials [153-155], and opals based on the deposition of silica, titania, and/or ceria in the voids of an ordered array of PMMA spheres [156]. A more extensive overview of photonic materials by sol-gel method can be found in Chapter 28. 

Ordered Array Structure of Polystyrene-Encapsulated Polydiacetylene Nanocrystals... 

---