n the present work, by using methylene blue (MB) as an electroactive probe, the hydrophobic properties of methylcellulose (MC) coated on a glassy carbon electrode were studied at different temperatures by electrochemical voltammetric method. It was found that, compared with the corresponding bare electrodes, the formal potential E⁰⁽ of MB on the MC modified electrodes shifted positively, and both the cathodic peak current i_pc and anodic peak current i_pa increased with temperature in the range of 45～70 ℃, indicating that hydrophobic bonding occurred between MC macromolecules, and that such an interaction tended to intensify with increasing the temperature. In addition, the ratio of the anodic to the cathodic peak currents i_pc/i_pa of modified electrodes were less than 1, being 0.70, and no single absorption peak of MB was observed on the cyclic voltammograms, which implied MB weakly absorbing on the MC film. The obtained experimental results also showed that the application of electrochemical methods to investigate the gelation mechanism of MC at a molecular level provided a useful complement.

Key words: methylcellulose, methylene blue, hydrophobic interaction, cyclic voltammetry, polysaccharide