Acrylic protective coatings modified with titanium dioxide nanoparticles: Comparative study of stability under irradiation

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• 作者：Dominique Scalarone ; Massimo Lazzari ; Oscar Chiantore
• 关键词：Acrylic coatings ; Titanium dioxide ; Nanoparticles ; Photodegradation ; Self-cleaning
• 刊名：Polymer Degradation and Stability
• 出版年：2012
• 出版时间：November, 2012
• 年：2012
• 卷：97
• 期：11
• 页码：2136-2142
• 全文大小：897 K

文摘

Acrylic coatings based on Paraloid B72 were modified with different types of titanium dioxide nanoparticles to obtain transparent, non-yellowing and chemically stable coatings, having also self-cleaning properties. To finely disperse the inorganic nanoparticles in the polymer matrix two strategies were followed: i) ex-situ functionalization of nanoparticles and ii) use of organic-inorganic coupling agents. Characterization focussed especially on the photooxidative stability of TiO₂ modified coatings. This is actually one of the most critical aspects of organic materials containing photoactive nanoparticles. The highly oxidant environment produced on the catalyst surface by photogenerated species is capable to mineralize many organic compounds, but in a poorly selective way, and this often undermines the stability of the polymer that binds the photocatalyst. Improved dispersability of TiO₂ nanoparticles generally resulted in a diminished chemical stability of the acrylic medium, but by using tetraethoxysilane (TEOS) as a coupling agent, oxidation and cross-linking reactions were considerably reduced, ensuring better stability and reversibility in comparison to Paraloid coatings containing photoactive TiO₂ nanoparticles without TEOS.