Preparation of transparent superhydrophobic silica coatings on glass

Superhidrofobnost je lastnost površine, da jo kapljica vode čim manj omoči. Površino definiramo kot superhidrofobno, če je kontaktni kot med vodo in površino večji od 150°. Načinov omočitve oziroma stanj omočitve površine je več. V primeru, da kapljica omaka površino v Cassie-Baxterjevem stanju, kapljica hitro odteče z minimalno nagnjene površine. V panogi filmografije in fotografije vodne kapljice na lečah kamer in fotoaparatov motijo zajemanje slike. V snemanju vodnih športov je verjetnost, da vodne kapljice vsaj opršijo lečo kamere, precej velika. V magistrskem delu smo poskusili s preprosto in cenovno ugodno metodo pripraviti superhidrofoben in prosojen premaz na steklu. Reakcijo polimerizacije silanov, s katero smo pripravili površine, smo skušali optimizirati za večje vzorce. Reakcijo smo skušali modificirati glede na količine dodanih reagentov, način katalize, z izbiro primerne atmosfere ter z načinom izvleka vzorca iz raztopine. Najboljše rezultate smo prenesli na lečo športne kamere GoPro. Vzorcem smo z optičnim tenziometrom izmerili kontaktni kot površine z vodo, s spektrofotometrom smo izmerili delež optične prepustnosti vzorca, z vrstičnim elektronskim mikroskopom (SEM) posneli nekaj slik površin ter z lepilnim in brisalnim testom preverili odpornost proti abraziji. Uspešno smo pripravili superhidrofobno prosojno površino na steklu, vendar z nekaj težavami. Homogenost nanosa premaza je v veliko primerov slabša, odpornost na abrazijo je slaba, kar pomeni, da za praktično uporabo ta metoda ni najbolj primerna.Superhydrophobicity is the property of a surface, that a drop of water wets it as little as possible. A surface is defined as superhydrophobic if the contact angle of the water on it is greater than 150°. Superhydrophobic surface can be wetted in several different states. In the event that a droplet soaks the surface in the Cassie-Baxter state, the droplet quickly drains from the minimally inclined surface. In the filmography and photography industry, water droplets on the lenses of cameras interfere with the clarity of the image. This is especially notable in shooting water sports, where the probability of water droplets at least spraying the camera lens is quite high. In the master\u27s thesis, we tried to prepare a superhydrophobic and transparent coating on glass with a simple, low-cost method. Superhydrophobic coating was made by polymerization of silanes. We tried to optimize the reaction for larger samples. An attempt was made to modify the reaction, varying the amounts of reagents added, the method of catalysis, the choice of atmosphere, and the method of extracting the sample from the solution. The best results were transferred onto the lens of the GoPro sports camera. The contact angle with water was measured with an optical tensiometer, the proportion of optical transmittance of the sample was measured with a spectrophotometer, a few images were taken with a scanning electron microscope (SEM) and abrasion resistance was tested with a tape and wiping test. We have successfully prepared a superhydrophobic transparent surface on glass, but not without issues. The homogeneity of the coating application is in many cases inferior and the abrasion resistance is poor, which means that this method is not the most suitable for practical use