改性PAN纤维与Fe3+的配位反应及配合物的催化性能

采用盐酸羟胺和水合肼的混合物分别对PAN纤维进行改性制备了偕胺肟改性PAN纤维(AO-PAN)和混合改性PAN纤维(M-PAN), 并分别与Fe³⁺进行配位反应生成两种改性PAN纤维铁配合物(Fe-AO-PAN和Fe-M-PAN). 研究了配位反应的动力学特性及温度和Fe³⁺初始浓度的影响, 并采用DRS和ESR技术比较了两种不同改性PAN纤维铁配合物对偶氮染料活性红195氧化降解反应的催化性能. 结果表明, 在所设定的温度和浓度范围内, 两种改性PAN纤维与Fe³⁺之间的配位反应平衡符合Langmuir 和Freundlich 吸附等温模型以及Lagergren准二级动力学方程, 并且AO-PAN比M-PAN更容易与Fe³⁺发生配位反应. 在相同条件下AO-PAN与Fe³⁺反应的配合量和反应速率常数均比M-PAN与Fe³⁺反应的高. 两种配合物对染料的氧化降解反应具有催化作用, 暗态条件下Fe-M-PAN比Fe-AO-PAN表现出更高的催化活性, 而光辐射条件下Fe-AO-PAN的催化活性显著增强.

Coordination of Modified PAN Fibers with Fe3+ and Catalytic Activity of Their Complexes for Dye Degradation

The amidoximated PAN fiber(denoted as AO-PAN) and the mix-modified PAN fiber(denoted as M-PAN) were prepared with hydroxylamine and its mixture with hydrazine, and then used to coordinate with Fe3+, respectively, to produce two Fe-modified PAN fiber complexes(denoted as Fe-AO-PAN and Fe-M-PAN, respectively). Coordinating kinetics of both modified PAN fibers with Fe3+ was mainly studied, and effect of temperature and Fe3+ initial concentration on coordinating kinetics were also examined. The catalytic activities of both Fe-modified PAN fiber complexes were investigated in the oxidative degradation of an azo dye(Reactive Red 195) by DRS and ESR methods. The results indicated that within the observed temperature and concentration range, equilibrium data for the coordination of Fe3+ with two modified PAN fibers were obtained and correlated with Langmuir and Freundlich isotherm equations, and coordination kinetics showed better agreement with the Lagergren second order equation. Fe coordinating capacity and reaction rate constant of AO-PAN to Fe3+ were higher than those of M-PAN to Fe3+ at the same conditions, indicating that AO-PAN reacted with Fe3+ more easily than M-PAN. Two Fe-modified PAN fibers complexes have the significant catalytic effect on dye degradation, and Fe-AO-PAN showed the stronger catalytic performance than Fe-M-PAN in the dark. Moreover, catalytic ability of the Fe-modified PAN fiber complexes, especially Fe-AO-PAN was remarkably enhanced by light irradiation.