STABILIZATION OF RUTILE TiO2 NANOPARTICLES WITH GLYMO IN POLYACRYLIC CLEAR COATING

STABILIZACIJA RUTIL TiO2 NANODELCEV Z GLYMO V POLIAKRILNEM TRANSPARENTNEM PREMAZU

Jerneja Godnjavec1, Bogdan Znoj1,2, Jelica Vince2, Miha Steinbucher2, Andrej Žnidaršič3, Peter Venturini1,2

1Center of Excellence for Polymer Materials and Technologies, Tehnološki park 24, 1000 Ljubljana, Slovenia
2Helios Group, Količevo 2, 1230 Domžale, Slovenia
3Kolektor Nanotesla Institut Ljubljana, Stegne 29, 1521 Ljubljana, Slovenia

[email protected]

Prejem rokopisa – received: 2011-02-15; sprejem za objavo – accepted for publication: 2011-07-06

Titanium dioxide (TiO2), in the crystal form of rutile with high refractive index, 2.7, is one of the most important inorganic pigments. In the recent years nano TiO2 has attracted interest as an inorganic material for nanocomposites. It is used for the development of photocatalysts1,2, semiconductors in solar cells3,4 and for the protection of materials from UV damage5–8. To achieve high UV absorbing efficiency of TiO2 nanoparticles into polymer matrix and to yield a better compatibility with polymeric materials surface treatment of TiO2 nanoparticles with 3-glycidyloxypropyltrimethoxysilane (GLYMO) in a polyacrylic clear coating was investigated. The grafting of GLYMO on the TiO2 nanoparticles surface was characterized with TGA and FTIR techniques. The stability of TiO2 nanoparticles in a acrylic clear coating was evaluated by zeta potential measurement. Microstructural analysis of nanoparticles was done by SEM and the influence of surface treatment on stability of nanoparticles in dispersion and acrylic coating was analysed. Finally the UV absorption effectivness of acrylic clear coating with treated nanoparticles of rutile TiO2 was measured to determine the effect of improved dispersion. The performance of nanocomposite coatings was demonstrated trough accelerated weathering by gloss measurement. The results showed that surface treatment of TiO2 nanoparticles with GLYMO improves nanoparticles dispersion and preserves UV protection of the acrylic clear coating.

Keywords: titanium dioxide, nanoparticles, polyacrylic clear coating, surface treatment, GLYMO, UV protection

Titanov dioksid (TiO2), v rutilni kristalni obliki z visokim lomnim količnikom, 2.7, je eden najbolj pomembnih anorganskih pigmentov. V zadnjih letih je nano TiO2 pritegnil pozornost kot anorganski material za nanokompozite. Uporablja se za razvoj fotokatalizatorjev1,2, polprevodnikov in soalrnih celic3,4 in za UV zaščito materialov5–8. Da bi dosegli ustrezno dispergiranje TiO2 nanodelcev v polimerni matrici in boljšo kompatibilnost s polimernimi materiali smo preiskovali površinsko obdelavo TiO2 nanodelcev v poliakrilnem transparentnem premazu. Za optimizacijo dispergiranja je bila površina nanodelcev obdelana z 3-glicidiloksipropiltrimetoksisilanom (GLYMO). Pripenjanje GLYMO na površino TiO2 nanodelcev smo ovrednotili z termogravimetrično analizo (TGA) in s FTIR spektroskopsko analizo. Stabilnosti TiO2 nanodelcev v akrilnem transparentnem premazu smo analizirali z meritvijo zeta potenciala. Mikrostrukturno analizo nanodelcev izvedli s SEM. Na koncu smo analizirali učinkovitost UV absorpcije akrilnega transparentnega premaza z površinsko obdelanimi rutil TiO2 nanodelci, da bi določili efekt izboljšane disperzibilnosti. Z izpostavo pospešenega staranja smo določili funkcionalnost nanokompozitnih premazov na osnovi meritve sijaja. Rezultati so pokazali da povšinska obdelava TiO2 nanodelcev z GLYMO izboljša disperziblnost nanodelcev in ohrani UV zaščito akrilnega transparentnega premaza.

Ključne besede: titanov dioksid, nanodelci, poliakrilni transparentni premaz, površinska obdelava, GLYMO, UV zaščita