Polimer kaplamaların optik ve ıslanabilirlik özelliklerinin araştırılması

Controlling wettability is an important property and highly desired by industry due to its wide range of advantages, such as; anti-bacterial, anti-ice and self-cleaning. Obtaining such advantages through engineering surface coatings presents highly challenging environment because, for example, one need to design highly porous surface for a chemically hydrophobic polymer coating to obtain anti-icing or self cleaning properties but porosity decreases light propagation and made the material opaque. Real struggle, and the most desired by industry, is finding the Goldilock Zone for such coatings, if not the perfect one. Controlling liquid behaviour is an ancient dream for us sapiens. We crafted cups to hold, canals to channel even built dams to harness the power within. Over the years, despite getting better at capturing the liquid, we were unable to prevent its harmful or undesirable effects after a certain point. It has been recently emphasized that nature is in fact very successful about avoiding its harmful effects with presenting liquid repellent properties. Water striders, a bug which have the ability to stand on water using its superhydrophobic legs, and water lilies (lotus) with self cleaning properties can be given as natural examples due to their unique water repellent properties. Learning the ways of nature about how to deal hazardous environment or how to enhance our inventions is the best key for success in engineering. Water repellent surfaces attracts many attention from industry with not only their self cleaning properties but also anti-fouling, drag reduction and many properties that were mentioned above. Two heading of water repellent surfaces can be mentioned as focussed in this thesis; hydrophobic surfaces and superhydrophobic surfaces where surfaces that have water contact angles larger than 90° called hydrophobic and larger than 150° called superhydrophobic. Main reason for the focus on these topics is their potential on marine enhancement properties. Drag reduction would be reduce carbon emissions in tremendous amounts when considered that the global shipping sector is responsible for approximately %2 of global greenhouse gas emissions which can be comparable for even countries. Anti-ice property could make working conditions on ships over cold climates better and increase the life expectancy of ships. Direct effect of water repellent properties will most likely be on hull applications as presenting anti-fouling properties and substituting present poisonous coatings with non-poisonous superhydrophobic coatings. The aim of this study is to create a knowledge basis of further studies and marine applications based on water repellent surfaces. High density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polyproplyne-polyethylene copolymer (PPPE), polyvinyl alcohol (PVOH), nylon 6 (N6), nylon 6,6 (N66), polystyrene (PS), poly(methyl methacrylate) (PMMA) and polyvinyl acetate (PVAc) coatings were tested for surface and optical properties. Surface free energy studies were conducted and correlations were presented. Great deal of data were obtained in order to understand polymer surface behaviours as well as how to enhance the properties. Last study was performed using dispersed SiO2 nanoparticles in order to create surface roughness. Polystyrene was chosen for this study for its adequate properties such as, high contact angle value, relatively low surface energy and easy to work under room conditions as well as high transmittance. As a result of this study, superhydrophobic SiO2 nanoparticle dispersed polystyrene coatings were obtained. Extensive correlations were derived between surface and optical properties with respect to the nanoparticle content.