Invited Paper: Fabrication Of Antireflection Coatings For Displays

Antireflection and antifogging coatings were fabricated on polycarbonate substrates using the layer-by-layer self-assembly of polyelectrolytes and silica nanoparticles. Antireflective coatings were also built on glass substrates by alternating spraying polyelectrolyte and silica nanoparticle solutions. The transmittance of the sample with both sides coated using the dipping method is above 99 % while the coating built through spraying can reduce the one side reflection from 4% to 1 %. Such technology provides a simple approach to fabricate antireflection coatings on displays. © 2008 SID

Fabrication Of Anti-Reflection Coatings On Plastics Using The Spraying Layer-By-Layer Elf-Assembly Technique

Anti-reflection (AR) coatings on plastic substrates have been extensively investigated with the development of large-area LCD and LED displays. A robust AR coating on plastics requires strong adhesion to the substrate, precise thickness and refractive index, and abrasion resistance. In this paper, abrasion-resistant AR coatings were fabricated on polycarbonate substrates using the layer-by-layer spraying deposition of poly(allylamine hydrochloride) (PAH) and silica nanoparticles. The adhesion between the substrates and coatings was enhanced by treating the polycarbonate surfaces with aminopropyltrimethoxylsilane (APTS). The porous low-refractive-index PAH/silica-nanoparticles multilayers were constructed by the layer-by-layer spraying of PAH and silica-nanoparticles aqueous solutions onto the functionalized substrates. The subsequent treatment of the porous coatings with tetrahydroxylsilane leads to stable abrasion-resistant AR coatings. The resultant AR coatings can reduce the reflection from 5 to 0.3%. The reported technique provides a cost-effective method for large-scale production of AR coatings on plastic substrates. © Copyright 2009 Society for Information Display

Conformal Switchable Superhydrophobic/Hydrophilic Surfaces For Microscale Flow Control

The development of microvalves is essential to realize a fully integrated system for nano/microliter fluid handling in microfluidic devices. Microvalves that utilize passive fluidic manipulation employ a hydrophobic surface in a microchannel network in which the operation is controlled by the interfacial tension of the liquid-air-solid interface. In order to obtain a switchable valve in microfluidic channels, conformal hydrophobic/hydrophilic and superhydrophobic/hydrophilic thermal switchable surfaces were fabricated by the layer-by-layer deposition of poly(allylamine hydrochloride) (PAH) and silica nanoparticles followed by the functionalization of a thermosensitive polymer-poly(N-isopropylacrylamide) (PNIPAAm) and perfluorosilane. A fully integrated microfluidic valve using a thermal switchable superhydrophobic/hydrophilic polymer patch has been fabricated. At 70 °C, the valve is superhydrophobic and stops the water flow (closing status) while at room temperature, the patch becomes hydrophilic, and allows the flow (opening status)