Electrochemical characteristics of dip-coated poly (2-cinnamoylethyl methacrylate) (PCEMA) films on Au surfaces

The electrochemical behavior of poly (2-cinnamoylethyl methacrylate) (PCEMA ) coatings, dip-coated on Au electrodes from PCEMA/THF solutions, was inves tigated primarily in pH 7 buffer solution. The thickness and mass of the PC EMA coatings on Au sputter-coated quartz crystals, established using ellips ometry and mass measurement (QCMB) techniques, were found to initially incr ease rapidly and then linearly with increasing PCEMA concentration of the d eposition solution, while the coating density was found to be higher at the PCEMA/Au interface. The PCEMA coverage of Au call be established from the magnitude of the compact Au oxide film (alpha -Au oxide) oxidation/reductio n charges in pH 7 buffer solution and was found to increase with the concen tration of PCEMA in the TI-IF solution. The presence of the PCEMA film on A u was found to promote the growth of a hydrous beta -Au oxide film, normall y formed at bare Au only when much higher potentials are applied. The stabi lity of the PCEMA coating in basic and acidic solutions, and the resistance of the PCEMA coating to degradation by extreme anodic and cathodic polariz ation, ale also discussed. (C) 2000 Elsevier Science Ltd. All rights reserv ed.