Kırmızı Lahana Antosiyaninlerinin Mika Titanya Özel Etki Pigmentleri Üzerine Çöktürülmesi

Abstract

Anthocyanin pigments extracted from Red Cabbage (Brassica oleracea) were deposited at different pH values on formerly synthesized mica-titania pigments after a purification step. Both anthocyanin pigments and mica/titania/anthocyanin pigments are investigated by using infrared, UV/VIS and fluorecence spectroscopies in order to understand the interactions of anthocyanins with the nano-titania surfaces. Anthocyanins have been considered as dye components in dye sensitized solar cells. The pH of the deposition medium was not investigated as a parameter in those studies and generally kept acidic (around a pH of 2-3). Therefore it was speculated that a dominant form of anthocyanin was deposited and responsible of the charge transfer reactions. It was reported that the lower the fluorescence, the higher would be the charge transfer efficieny. Here the effect of pH on structural transformations of anthocyanins was investigated with a reference to their interaction with the rutile nano-titania Surfaces in the deposition medium. The fluorecence of the combination pigments at higher pH values was lower compared to those of at lower pH values, due to the quenching effect among different forms. It can be proposed that a control on pH of the deposition medium can improve the cell efficiencies.