The Optimization of Electrical Conductivity Using Central Composite Design for Polyvinyl Alcohol/Multiwalled Carbon Nanotube-Manganese Dioxide Nanofiber Composites Synthesised by Electrospinning

This research reports the characterization and statistical analysis of electrical conductivity optimization for polyvinyl alcohol (PVA)/multiwalled carbon nanotube (MWCNT)-manganese dioxide (MnO2) nanofiber composite. The Central Composite Design (CCD), the most common design of Response Surface Methodology (RSM) had been used to optimise the synthesis process of PVA/MWCNT-MnO2 nanofiber composite. The process parameters studied were; applied voltage (16 kV - 30 kV), solution flow rate (3- 5 mL h-1) and surrounding temperature (17-30°C). Analysis of variance (ANOVA) was used to analyse the experimental results. The prediction of optimum value and the clarification of the interactions between the specified range factors were done by using the quadratic model. The results revealed that at the parameter condition of 23 kV for applied voltage, 4 mL h-1 solution flow rate and 18°C of surrounding temperature, the highest electrical conductivity of 2.66x10-5 S cm-1 was obtained. The predicted (2.81 x10-5 S cm-1) value after optimization process was in good agreement with the experimental data (3.06 x10-5 S cm-1). The model was able to accurately predict the response of electrical conductivity with less than 10% error. Referring to ANOVA results, it was statistically found that the surrounding temperature parameter given significant effect to electrical conductivity of PVA/MWCNT-MnO2 nanofiber composite in both single parameter and interaction between parameter.