Electroactive composites based on polydimethylsiloxane and some new metal complexes

Three different small molecule or polymeric well-determined complex structures containing siloxane moieties and 3d metals were incorporated into a polymeric matrix based on a polydimethylsiloxane of low molecular weight. After the incorporation of the complex, matrix crosslinking was performed with tetraethylorthosilicate, resulting in free-standing films. The films were investigated by scanning and transmission electron microscopy (SEM, TEM), dynamic vapour sorption (DVS) analysis, stress-strain measurements and dielectric spectroscopy. The presence of the siloxane moiety in the ligand (by its surface effect) improves the compatibility between the metal complex and the silicone matrix, which ensures good mechanical properties. Thus, modulus values between 0.10 and 0.50 MPa and elongations of 210-380% were obtained. Depending on the metal type and the complexation pattern, an increasing of the dielectric constant value up to 4.6 as compared with a value of 2.5 for the silicone matrix was obtained. The samples showed good electromechanical actuation behaviour even at small voltages.