Metallic Interaction in Polythiophene-Ti Plasma Composites

This work presents a study about the structure and morphology of thin plasma composite films of polythiophene (PTh) with metallic particles of Ti (PTh-Ti). The objective was to study the water affinity and electric conductivity in PTh with the addition of metallic phases. The hydrophilicity was studied with the contact angles formed between water and surfaces, and the electric conductivity was calculated with the resistance measured in a two-probe device. The structure and morphology of the composites were studied with X-ray diffraction and scanning electron microscopy. The results indicated that PTh-Ti formed thin films of hybrid composites with oxidized Ti and Fe additional particles released from the electrodes used in the syntheses. The metallic fraction resulted in 2 diffraction angles at 31.6° and 66.1° product of the complex interaction among Ti, resembling orthorhombic TiO2 structures, and PTh. The metallic particles and iodine, added as a dopant to the composites to increase conductivity, reduced the hydrophilicity with water in a competition between roughness and chemical composition. In these conditions, the contact angles resulted between 46° and 75°. The electric conductivity was about 10-6 S/m increasing one order of magnitude with the metallic fraction. However, the high resistance of the polymeric fraction apparently dominates the transference of charges.