Darran R. Cairns

Template-assisted encapsulation of fluorinated silanes in silica films for sustained hydrophobic-oleophobic functionality.

This work explores the use of templated silica films as scaffolds for encapsulating surface-segregating functional organic moieties as a mesoscopically dispersed phase with the goal of imparting sustained functionality. Block copolymer surfactant templated hydrophobic-oleophobic fluorinated silica films were synthesized via sol-gel co-condensation and coated on glass substrates. Fluorosilane and surfactant template concentrations were varied, and coating surface properties measured before and after abrasion of the top surface. Surface physical and chemical properties were investigated using XPS and contact angle measurements. Nitrogen adsorption porosimetry and TEM were used to examine the effect of templating and fluorosilane encapsulation on the surrounding silica framework. The results show that surfactant template concentration may be used to tune the dispersion of the fluorosilane-rich phase within the silica film in order to allow exposed surfaces to maintain much of the original functionality of the pristine top surface.

36.2: Quantifying “Sparkle” of Anti-Glare Surfaces

Textured surfaces are widely used for anti-glare surfaces. Modern high resolution displays are placing higher demands on these layers. Developing techniques to quantify the subjective appearance of speckle caused by overlays is crucial to developing the next generation of overlays. We report on the use of a simple optical bench to measure speckle contrast and the comparison of these measurements to subjective scores for sparkle. We show that for a set of specially prepared acid etched samples there is a direct correlation between speckle contrast and subjective sparkle.

Transparent conductive carbon‐nanotube films directly coated onto flexible and rigid polycarbonate

— Carbon nanotubes have quickly emerged over the last several years as a potential candidate material to replace metal oxides in devices which require transparent and conductive electrodes. Typically, these materials are coated onto substrates such as PET and PEN for flexible electrodes and glass for rigid electrodes. Recently, there has been interest in more durable and lightweight substrates to replace glass, one such substrate being polycarbonate. Sputter coating of indium tin oxide onto polycarbonate leads to low conductivity and inconsistent results, due to out-gassing and materials mismatch issues. In this work, it is shown that direct coating of carbon nanotubes onto polycarbonate leads to high-performance films with facile manufacturing.

Microtribological study of internal surfaces of fluorinated mesoporous silica films.

Fluorinated mesoporous silica films were synthesized via sol-gel co-condensation and coated on glass substrates. Surfactant template concentrations were varied to examine the effect of encapsulated organic functionality on the microtribological properties of films using atomic force microscopy. Films were tested as synthesized and also after being abraded to expose interior mesostructured surfaces. Results indicate that templating allows fluorinated moieties to become encapsulated within the film, which affect the tribological properties of the exposed internal surfaces. Depending on the amount of template added, the interior surfaces were able to achieve a friction level comparable to that of conventional monolayers. The dependence of friction on sliding speed revealed that fluorinated templated films have tribological properties intermediate to those of a nonfunctional surface and a conventional fluorinated monolayer.

P-58: Laser Speckle of Textured Surfaces: Towards High Performance Anti-Glare Surfaces

Textured surfaces are widely used for anti-glare and anti-newton ring layers. Modern high resolution displays are placing higher demands on these layers. We are developing an understanding of the relationships between surface topography and speckle are crucial to enable the design of the next generation of these layers.

P‐73: Mechanical Assisted Corrosion: An Investigation of Thin Film Components used in Flexible Optoelectronic Applications

During flexible optoelectronic device packaging, acid containing layers initiate the functional failure of the underlying indium tin oxide film. We experimentally investigate the stressassisted corrosion cracking of thin conductive optoelectronic components. It is essential to understand the stress corrosion mechanisms in order to design highly durable flexible electronic structures.

Polymer Skins With Switchable Roughness

Polyvinyl alcohol (PVA) films with embedded electrically-responsive liquid crystal (LC) ellipsoids were fabricated to develop a membrane coating featuring tunable roughness. Membranes (∼30 microns thick) were placed between opposing pieces of indium-tin oxide (ITO) glass, creating electrodes for creation of a uniform electric field. Applied voltages ranged from 0V–350 V, as films were observed using an optical microscope. Thin-film interference patterns were observed in various regions of each film and were measured. Contour plots of film displacement were created and showed elevations across the observed region. The area of the first dark fringe regions, assumed to be in contact with the top glass surface, were measured as a function of applied voltage. The maximum displacement of the film was estimated to reach 1.5 microns and the area in contacted with the top glass surface increased 127% between 0–350 V. Finite element modelling results illustrate the influence of polarity on the roughness of the film surface.Copyright

P‐184: Highly Durable Transparent Carbon Nanotube Films for Flexible Displays and Touch ‐ Screens

This paper describes a durable carbon nanotube (CNT) film, used in flexible displays and touch-screens, and its mechanical properties. CNT films as thin as 10 nm thick have properties approaching those of existing electrodes based on indium tin oxide (ITO) but with significantly improved mechanical properties. These durable CNT-based electrodes hold the key to developing robust, large-area, lightweight, optoelectronic devices such as lighting, displays, electronic-paper, and printable solar cells. Such devices could hold the key to producing inexpensive green energy, providing reliable solid-state lighting, and significantly reducing our dependence on paper.

59.2: Durable Solid State Flexible LED Devices

Energy efficient solid state lighting flexible and lightweight devices can offer an attractive alternative to bulky traditional rigid lighting solutions. We demonstrate a highly durable solid state flexible light emitting diode device and we report on critical factors during device manufacturing and use. We also propose alternative materials in order to further enhance the operational lifetime of the device.

Electrically Switchable Liquid Crystal Polymer Rod Actuators

Stimulus responsive liquid crystal nanorods, 60 μm in length and 200 nm in diameter, were fabricated by a template synthesis technique. The liquid crystal, RM 257, is a reactive monomer which polymerizes with the application of UV light. After polymerization the liquid crystals orientational order is permanently “frozen”. Therefore, the subsequent structures are temperature independent after curing. In this study the liquid crystal was confined in the pores of Anopore membranes before curing, which results in rod structures after photo-polymerization. After fabrication, the rods were observed under the application of both AC and DC electric fields. DC fields were noted by either up and down or translational movement of the rods. Application of AC fields resulted in random movement of the rods.