Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"superhydrophilic"”.
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Evaporation-induced non-wetting droplets on superhydrophilic surfaces
… surfaces at room temperature demonstrated superhydrophilic behavior with liquid filling the voids between pillars resulting in very low contact angle, and hence complete wetting. However, when the microstructured surface was superheated above a critical superheat, the superhydrophilicity …
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Evaluation of superhydrophilic polyelectrolyte multilayered films for anti-fogging applications
… work in fabricating nanoporous PEM films with superhydrophilic characteristics that demonstrate great promise for anti-fogging and anti-reflection glass coating applications. The automotive glass industry is then identified as a potential market for this technology, and competing anti-fogging …
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Neutron scattering and microscopy studies of the structure and dynamics of water near a nanostructured hydrophilic copper oxide surface
Recently, it has been shown that superhydrophilic coatings of "grass-like" cupric oxide (CuO) nanostructures can significantly improve the thermal performance of heat transfer devices known as oscillating heat pipes (OHPs). The origin of this enhanced performance is currently unknown, but it is …
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Advances in Microfluidics: A Lab-on-a-Disk Approach to Solve Dairy Industry Problems
… through the creation of superhydrophobic and superhydrophilic microfluidic valves in polycarbonate by laser modification. Surface wettability was dramatically changed by laser treatment and was dramatically different with different pulse-length and wavelength. Use of a femtosecond (fs) laser …
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Chemical Surface Modification of Polycarbonate to Increase Hydrophilicity
… of polycarbonate to be more hydrophilic, ideally superhydrophilic with a contact angle less than 10°. Many chemicals were tested to see if they could increase the polarity of polycarbonate. Polycarbonate was partially submerged in pure chemicals for 2 hours at room temperature to determine its …
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Wetting and phase-change phenomena on micro/nanostructures for enhanced heat transfer
… the intrinsic wettability of materials to create superhydrophilic or superhydrophobic surfaces. Such extreme wetting properties can influence the heat transfer performance during phase-change which is of great importance in a wide range of applications including thermal management, building …
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Impact of heat exchanger surface wettability on condensation, frosting, and defrosting performance under practical testing conditions
… newer approaches, such as superhydrophobic, superhydrophilic, quasi-liquid surfaces, and slippery liquid-infused porous surfaces, have shown promise in laboratory studies but remain insufficiently explored in system-level evaluations. This dissertation investigates a broad set of engineered …
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Influence of counter-ions on antifogging coatings
The influence of different counter-ions on the superhydrophilic and antifogging behavior of polyelectrolyte multilayers was examined. Multilayers assembled with a polymer anion and amine-modified silica nanoparticles were treated with salt solutions of monovalent and divalent cations. Refraction …
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LASER ABLATION FOR COPPER OXIDE NANOWIRES GROWTH AND ITS APPLICATION FOR OIL-WATER SEPARATION
… and catalyst-free process. The resulting superhydrophilic nano-textured surface demonstrated efficient oil-water filtration ability which would be useful in the separation of emulsions from oil spill accidents and wastewater pollution. This work has potential for large scale, …
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Tunable wettability of microstructured polypyrrole films
… switches between the superhydrophobic and superhydrophilic states is discussed. The polymer is doped with perfluorooctanesulfonate ions which diffuse in and out of the film upon an electric stimulus, causing a change in the material's surface energy. The effect of changing different …
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Fabrication of anti-reflective and imaging nanostructured optical elements
… make the surfaces either superhydrophobic or superhydrophilic, depending on the applications, such as antifogging and self-cleaning glass. Novel lithographic techniques result in high patterning accuracy over large surface areas, and is easily adaptable to nanoimprinting for future mass …
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Preparation and Biocompatibility of Electrospun Zwitterionic Poly(Sulfobetaine Methacrylate) for Wound Dressing Applications
… PSBMA has been well studied for its superhydrophilic and ultralow biofouling properties, making it a promising material for superabsorbent and nonadherent wound dressings. Electrospinning provides multiple desirable features for wound dressings, including high absorptivity due to high …
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Aging Effect in the Wettability of Nickel Nanorod Arrays
… that the nickel nanorod arrays were initially superhydrophilic. As the samples aged in air, however, they all showed increasing contact angles as a function of time that were nonlinear with different rates. The results can be grouped into two categories: thinner samples with shorter deposition …
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Micro and nanostructures for two-phase fluid and thermal transport
… at the less hydrophilic sidewalls while the superhydrophilic microstructures on the heated surface of the channel can maintain a liquid film by capillary wicking to promote thin film evaporation and prevent dry-out. Our experimental results show significantly reduced long-timescale (-seconds) …
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Electric field based fabrication methods for multi-scale structured surfaces
… for the development of superhydrophobic and superhydrophilic surfaces; sample applications include anti-wetting fabric, capillarity driven flow design, and critical heat flux enhancement. In many applications it is critical to understand how moving liquid water droplets will behave when they …
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Experimental investigation of effects of surface roughness, wettability and boiling-time on steady state and transient CHF for nanofluids
… pronounced if the initial heaters contained a superhydrophilic surface coating before use with nanofluids as opposed to the initial heaters being bare and uncoated. Additionally, the thickness of the nanocoating appeared to plateau after approximately 30 - 40 minutes of boiling time, and …
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Influence of Surface Wettability on Drop Dynamics and Condensation
… of this dissertation, a surface with switchable superhydrophilic to hydrophobic wetting behavior is developed that responds to temperature stimulus. This surface is successfully applied as a condenser that exhibits variable performance in its heat transfer coefficient by switching between the …
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Wettability on nanoparticle modified surface: for thermal engineering
… the rougher the surface. The goal is to obtain superhydrophilic surface, which is achieved at high particle concentration (1%wt) NBND. Microscopic analysis gives evidence of particle deposition after NBND. Nano-micro structures were studied using SEM. The images show the growth of “nano-grass” …
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Functional coatings deposited by an Atmospheric Pressure Plasma Jet (APPJ) system over Thermoplastic Elastomer (TPE) substrates
… distribution of fibers, poor adhesion and superhydrophilic character are the main drawbacks. Since TPE is a heat-sensitive material, an Atmospheric Pressure Plasma Jet (APPJ) system with a Dielectric Barrier Discharge (DBD) was used in this thesis. During the first group of scientific …
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Spray cooling applications for alternative energy vehicles
The number of electric and alternative fuel source vehicles has dramatically expanded in the last decade due to the proliferation of high energy-dense batteries and the lowering costs of hydrogen fuel vehicles. However, current generation heat exchangers take up more space in alternative fuel …
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