Abstract

The adsorption of alginic acid on a TiO<sub>2</sub> particle film from aqueous solution was investigated by attenuated total reflection infrared (ATR-IR) spectroscopy. ATR-IR spectra recorded at different pHs confirmed that alginate adsorption to TiO<sub>2</sub> is favored at pH 3.0 and no significant adsorption occurs above pH 5.0. Upon adsorption the carboxylic acid groups of alginic acid are converted to the carboxylate form and bind to surface Ti(IV) ions via bridging bidentate structures. Spectral analyses of the carboxylic acid and carboxylate stretching vibrations indicated that about three in four −COOH groups are converted to −COO<sup>−</sup> groups as they bind coordinately to TiO<sub>2</sub>. Additionally, the spectral data at pH 8.0 showed specific interactions of Ca<sup>2+</sup> ions with the free COO<sup>−</sup> groups of the polysaccharide backbone of adsorbed alginic acid.

PDF Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription