Electrochemical Characteristics and Stability of Poly(1,5-diaminoanthraquinone) in Acidic Aqueous Solution

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• 作者：Mingming Gao ; Fenglin Yang ; Xinhua Wang ; Guoquan Zhang ; Lifen Liu
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：November 22, 2007
• 年：2007
• 卷：111
• 期：46
• 页码：17268 - 17274
• 全文大小：208K
• 年卷期：v.111,no.46(November 22, 2007)
• ISSN：1932-7455

文摘

The electrochemical characteristics and stability of poly(1,5-diaminoanthraquinone) (P15DAAQ) has beeninvestigated in different acidic aqueous solution by electrochemical methods and Fourier transform infraredspectroscopy (FTIR). Cyclic voltammetry (CV) analysis suggests that electropolymerization consists of twophases-the deposition of P15DAAQ from the oxidation of 15DAAQ monomers and the polymer growthprocess. The CV and chronoamperometry (CA) data provide the evidence that ion transfers are differentbetween oxidation and reduction processes and are profoundly influenced by the sizes of ion radius duringthe redox process of P15DAAQ in acid solution. The H⁺ transfer is diffusionless, while the insertion/expulsionof large aqua anions is controlled by diffusion. A model is proposed to describe these ion transfer processes.In further CA research, the calculated diffusion coefficients of aqua anions in P15DAAQ are in the order ofCl^- > S > NO₃^- > P. As a result of stability research, it can be seen that degradation of the polymerexists not only in overoxidation but also in the stable redox reaction. The degradation rates of P15DAAQ inthe reversible potential region from -0.2 to 0.75 V obey the apparent first-order kinetic, and the degradationrate constants are 2.04, 4.93, 2.59, and 3.03 × 10^-5 s^-1 in HCl, H₂SO₄, HNO₃, and H₃PO₄, respectively.According to FTIR and CV, the quinone-like structure is destroyed, accompanied with conjugation length ofthe polymer's -bond being decreased and chains in the polymer being broken and recombined with anionscombined to the polymer, when P15DAAQ is potentiodynamically overoxidized at 1.5 V.