The effect of silicon dioxide on the elctrical conductivity of polypyrrole/poly (vinlychloride) blends as a conducting polymer for the ionic solutions detector

Polypyrrole/poly (vinyl chloride)-silicon dioxide conducting polymer composites has been investigated as conducting polymer for ionic solutions detector. These composites were prepared by mixing polypyrrole doped with carbon black and different of silicon dioxide loading as variable. The mixture was dissolved in 1-methyl-2-pyrrolidinone and then heated under boiling point to obtain conductive polymer solution. Poly (vinylchloride) carboxylated was dissolved in Tetrahydrofuran (THF) and heated until it becomes gel. The PPy/Si02 blend was mixed with PVC gel which was used as binder to improve the adhesion of the sensing material on sensor electrodes. PPy/PVC-Si02 conductive polymer composites samples had been characterized by FTIR DSC and XRD analysis. After the dropping of the samples to surface of PCB board of sensors, they dried into oven and then connected to precision multimeter to measure their resistance when applied to the solutions. The results showed the electrical conductivity increased with increasing Si02 content in composite. The PPy/PVC blends under SEM micrographs and XRD characterizations exhibited the agglomeration and intercalation between PPy and PVC/Si02 which supported the electrical conductivity result. The Potassium chlorate exhibited highest electrical conductivity compared to other solutions. The intermolecular interaction between PPy/PVC with Si02 is evidenced from FTIR analysis.