Lin, C. T. (Chhui-Tsu)
Ph.D. (Doctor of Philosophy)
Department of Chemistry and Biochemistry
Nanocomposites (Materials)||Coating processes||Coatings||Nanotechnology||Nanotechnology||Condensed matter physics
Nanotechnology applications in coatings have shown significant growth in recent years. Systematic incorporation of nano-sized inorganic materials into polymer coating enhances optical, electrical, thermal and mechanical properties significantly. The present dissertation will focus on formulation, characterization and evaluation of inorganic/organic hybrid nanocomposite coatings for heat dissipation, corrosion inhibition and ultraviolet (UV) and near infrared (NIR) cut applications. In addition, the dissertation will cover synthesis, characterization and dispersion of functional inorganic fillers.||In the first project, we investigated factors that can affect the "Molecular Fan" cooling performance and efficiency. The investigated factors and conditions include types of nanomaterials, size, loading amount, coating thickness, heat sink substrate, substrate surface modification, and power input. Using the optimal factors, MF coating was formulated and applied on commercial HDUs, and cooling efficiencies up to 22% and 23% were achieved using multi-walled carbon nanotube and graphene fillers. The result suggests that molecular fan action can reduce the size and mass of heat-sink module and thus offer a low cost of LED light unit.||In the second project, we report the use of thin organic/inorganic hybrid coating as a protection for corrosion and as a thermal management to dissipate heat from galvanized steel. Here, we employed the in-situ phosphatization method for corrosion inhibition and "Molecular fan" technique to dissipate heat from galvanized steel panels and sheets. Salt fog tests reveal successful completion of 72 hours corrosion protection time frame for samples coated with as low as ~0.7microm thickness. Heat dissipation measurement shows 9% and 13% temperature cooling for GI and GL panels with the same coating thickness of ~0.7microm respectively. The effect of different factors, in-situ phosphatization reagent (ISPR), cross-linkers and nanomaterial on corrosion and heat dissipation was discussed on this project.||In the third project, optically transparent UV and NIR light cut coating for solar control application was studied. On separate study for UV cut coatings, we have formulated UV-shielding coatings using ZnO nanoparticles fillers that have more than 90% UV absorption and above 90% visible transparency. In a separate part of the same project, we synthesized NIR-absorbing CsxWO 3 nanorods with uniform particle size distribution in 2 hours using a solvothermal method. Aqueous dispersion of the nanorods has showed high transparency (80-90%) in the visible range with strong NIR light shielding (80-90%). Preliminary work on sol-gel coatings of CsxWO3 showed high visible light transparency with excellent NIR shielding.
Eyassu, Tsehaye, "Inorganic/organic hybrid nanocomposite coating applications : formulation, characterization, and evaluation" (2014). Graduate Research Theses & Dissertations. 3587.
Northern Illinois University
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