Correlation between silane concentration and temperature operated toward conductivity of well-synthesized chitosan-fly ash composite membrane Scientific paper

Abstract

Composite membrane is synthesized using well-synthesized chitosan as matrix crosslink with fly ash as filler and modified using 3-glicydyloxypro­pyltrimetoxy silane coupling agent. XRD analysis is carried out to characterize fly ash. While, FTIR characterization is conducted to determine the interaction between chitosan matrix and fly ash that has been modified using silane. The emergence of a new absorption at wave numbers 1118.64 cm^-1 shows the inter­action between silane and fly ash. In addition, the widening of OH absorption shows that hydrogen bonds are formed between the silane and chitosan. The interaction is also demonstrated by the evenly distributed hills and valleys on AFM topography analysis. Characterizing the composite membrane with TGA analysis is done to determine thermal stability. While, proton conductivity of the composite membranes are measured using EIS. The highest conductivity values are obtained with the addition of 5 % silane concentration of 2.75´10^-4 S cm^-1 at room temperature, 3.995´10^-4 S cm^-1 at 40 °C, and 3.909´10-4 S cm^-1 at 60 °C. On the contrary, measurements at 80 °C, decomposition in all composite mem­branes occur. Thus, the crosslinked composite membrane chitosan–fly ash prepared by silane-crosslinking technique has potential to be applied with poly­mer electrolyte membrane fuel cell (PEMFC).