Study of the properties of LB films of a new cellulose derivative bearing terthienyl side groups

An electrochemically active derivative of cellulose bearing terthienyl side chains has been prepared starting from butylcellulose (degree of substitution=1.9) and 5(2-chloroethyl)-2,2′:5′,2′′-terthiophene (CETT). This polymer was suitable for application of the Langmuir–Blodgett (LB) technique in order to obtain organized films. The degree of order of such films was investigated by X-ray reflectometry and by UV-Vis and fluorescence spectroscopy, that showed a small but measurable alignment of the side groups. The TT side groups could not be addressed by cyclovoltammetry when the LB-architecture was probed; however, the same polymer in solution showed an irreversible signal in cyclovoltammetry. When the LB-architecture on gold substrate was contacted with a solution of 3-penthylthiophene electropolymerization of the latter could be achieved and islands of the poly(3-penthylthiophene) were observed with concomitant disappearance of the UV-signal of the grafted TT moieties.