This article presents a contribution to a better understanding of the effects of pH value on the morphology, conductivity, and reflection loss of polypyrrole (PPy) prepared at different pH values using indigo carmine (IC) as the synthesis template. The results indicate that the morphology of PPy changes from spiral rods to nonspiral rods, then to particles, which is attributed to the gradual morphological change of IC micelle templates from prismatic structure to rugby-like structure, and finally to spherical structure. Further study demonstrates that the conductivity of PPy decreases with the gradual decrease of the pH value, as a result of gradually increased contact resistance and the degree of electron delocalization. With the decrease of the pH value, the maximum reflection loss of PPy gradually increases and the corresponding loss peak moves to higher frequency points simultaneously.
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