Effect of dopant on the conductivity and stability of three different cotton fabrics impregnated with PEDOT:PSS

This study has investigated the electrical conductivity (sheet resistance) and morphological properties of dental cotton, textile cotton and gauze cotton after drop casting each type with mixtures of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as primary dopant and dimethylsulfoxide as secondary dopant to further enhance conductivity. These cottons were chosen because they are representative of the wide range of cottons available in the marketplace. Results show that the dental cotton with 96.82 wt% PEDOT:PSS had a minimum sheet resistance of 0.0615 Ω/□ by comparison with the gauze and textile cottons which showed sheet resistances of 0.5061 Ω/□ (64.79 wt% PEDOT:PSS) and 1.2159 Ω/□ (37.20 wt% PEDOT:PSS) respectively. Further, all sheet resistances were found to be stable over a period of approximately 1 month. The sheet resistances of the conductive cottons were also investigated as a function of temperature in the range from 30 to 100 °C.