有機フッ素化合物の気液界面吸着量とプラズマによる分解速度の関係

抄録

Perfluorooctanoic acid (PFOA: C₇F₁₅COOH) in water has been decomposed effectively by plasmas generated at a gas-liquid interface. During the decomposition of PFOA, perfluorocarboxylic acids (PFCAs: C_nF_2n+1COOH) with shorter carbon chains (n = 1-6) are generated as by-products. Since these PFCAs are surfactant, they adsorb to the gas-liquid interface and show high surface concentration. This study investigated the relationship between the adsorbed amount of the PFCAs and the rate of decomposition by a dc plasma. The adsorbed amount of the PFCAs at the gas-liquid interface increased as the length of the carbon chains increased, resulting in a higher rate of decomposition. However, the reaction rate reached saturation with a certain adsorption amount depending on the discharge current.