Završni premazi u graditeljstvu s učinkom samočišćenja

master's thesis

• Title (english): Final coatings in the building industry with self-cleaning effect
• Author: Lucija Pavić
• Mentor: Mirela Leskovac (mentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Krunoslav Žižek (član povjerenstva)
• Committee member: Vesna Ocelić Bulatović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2022-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Premazi su jedan od najstarijih načina obrade površina, a definiraju se kao materijali koji naneseni na podlogu imaju zaštitnu i estetsku ulogu. Nazivaju se kompozitnim materijalima jer njihov složeni sastav čini vezivo kao glavna komponenta koja sve ostale (pigmente, punila, aditive) nastoji povezati. Fasadni premazi su posebice izloženi atmosferilijama koje su neizbježne što zahtjeva njihovu stalnu obnovu radi estetskih i sigurnosnih razloga. Napretkom civilizacije čovjek nastoji pojednostaviti način života pa su tako istraživanja usmjerena na razvoj premaza koji bi imao učinak samočišćenja. Isto tako, svijest o ekološkoj sigurnosti potaknula je ideju o smanjenju organskih komponenti koji zauzimaju veliki udio u konvencionalnim premazima. Rješenje navedenih problema nastoji se pronaći u silikatnim premazima. Cilj ovog rada bio je ispitati utjecaj udjela koloidne nanosilike SiO2 i kalijevog vodenog stakla kao anorganskog veziva na svojstva silikatnog premaza te mogućnost postizanja učinka samočišćenja. U tu svrhu pripremljena su četiri formulacije premaza, jedna bez SiO2 koloida i tri s različitim omjerom vodenog stakla i SiO2 koloida. Uzorci su sadržavali ostale komponente u jednakim udjelima. Utjecaj udjela SiO2 i kalijevog vodenog stakla promatran je kod disperzija i suhih premaza u formi filma. Odmah nakon zamiješavanja disperzija premaza određene su osnovne karakteristike disperzija. Analizirana su reološka svojstva disperzija premaza. Zatim, za sve premaze određeni su adhezija na supstrat, vodoupojnost, propusnost na vodenu paru, kontaktni kut. Toplinska svojstva premaza analizirana su tehnikama diferencialne pretražne kalorimetrije (DSC) i termogravimetrijaske analize (TGA) analiza. Stabilnost filmova premaza analizirana je izlaganjem uzoraka prirodnom starenju na vremenskoj stanici i ubrzanom starenju u QUV komori. Učinak samočišćenja ispitan je internom metodom s ugljenom prašinom.

Abstract (english)

Coatings are one of the oldest methods of surface treatment that, when applied to the substrate, have protective and decorative properties. Coatings are also called composites due to their complex chemical composition, which consists of a binder as the main ingredient that combines other components (pigments, fillers, additives). Facade coatings are particularly exposed to the inevitable effects of weathering, which means that the coating must be constantly renewed for decorative and safety reasons. With the development of civilization, man strives to simplify various aspects of life, and as a result, some researches focus on the development of coatings with self-cleaning effect. At the same time, the awareness of ecological safety brought the idea of reducing volatile organic components, which have a large proportion in conventional coating formulations. The solution to the above problem is seen in silicate coatings. The aim of this work was to investigate the effects of different amounts of colloidal nano-silica (nano-SiO2) and potassium water glass as an inorganic binder on the properties of silicate coating and to test the possibility of achieving the self-cleaning effect. For this work, four dispersions were prepared, one of which didn't contain nano-SiO2 and the other three contained different amounts of nano-SiO2 and potassium water glass. The dispersions contained the same amount as the other components. The effects of different amounts of nano-SiO2 and potassium water glass on the properties of dispersions and dry films were investigated. Immediately after the preparation of the dispersions, the basic property was determined. The rheological properties of the dispersions were also investigated. The properties of the dry films were studied by analyzing the adhesion of the film to the substrate, water absorption, water vapor permeability, and contact angle. The thermal properties of the coatings were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The stability of the samples under atmospheric conditions was investigated by exposing them to six months of natural aging in the weathering station and conditions in the QUV accelerated weathering tester. The self-cleaning effect was studied by the internal method using carbon dust.

• Keywords: premazi; koloidna nanosilika; reološka svojstva; starenje; toplinska svojstva
• Keywords (english): coatings; colloidal nano-silica; rheological properties; aging; thermal properties
• Language: croatian
• URN:NBN: urn:nbn:hr:149:781039
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-03-23 12:43:11