Catalytic polymerization of aniline was carried out in sol-gel silicas doped with aniline and copper(II) salts as a catalyst in order to prepare polyaniline/silica hybrid gels. Aqueous solutions of aniline, sodium dodecyl sulfate, HCl, Cu(II) salts and tetraethoxysilane were mixed and stirred at room temperature. The obtained gels showed a deep green color during the drying process and had absorption peaks at ∼422 nm and ∼750 nm, thus indicating the formation of emeraldine salts type polyaniline in the sol-gel silicas. As for the formation of polyaniline, CuCl
2 was twice as active as CuSO
4 or Cu(NO
3)
2. It was confirmed that polymerization of polyaniline proceeds by utilizing copper(II) salts as a catalyst and oxygen as an oxidant in the sol-gel silica gels.
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