DOI: 10.3724/SP.J.1249.2020.05536
为提高复合吸波材料4,4'-二氨基二苯醚分子印迹聚合物(4,4'-diaminodiphenyl ether molecularly imprinted polymer,4,4'-ODL-MIP)-聚4,4'-二氨基二苯醚(poly 4,4'-diaminodiphenyl ether,P- 4,4'-ODL)(4,4'-ODL-MIP-P- 4,4'-ODL)的合成率,增强其电磁波吸收性能,探索在第2次电聚合过程中4,4'-ODL-MIP对模板分子4,4'-ODL的印迹吸附机制就十分重要. 以与4,4'-ODL-MIP-P- 4,4'-ODL的电磁波吸收性能密切相关的荷电量作为吸附量,在温度为298 K条件下, 直接拟合了Langmuir、Brunauer-Emmett-Teller(BET)、 Freundlich、Dubinin-Radushkevich(D-R)、 Temkin和Henry 6种吸附等温模型方程. 拟合数据显示,Langmuir、Dubinin-Radushkevich和Henry 3种等温吸附模型更适合模拟复合材料第2次电聚合中4,4'-ODL-MIP对溶液中4,4'-ODL的印迹吸附.同时,以荷电量所拟合的4种吸附反应动力学方程(准1级、准2级、Elovich及颗粒内扩散方程)结果显示,4,4'-ODL-MIP印迹吸附4,4'-ODL是准一级动力学反应,且反应速率大小受液膜和颗粒内扩散控制. 通过荷电量所计算的4,4'-ODL-MIP印迹吸附4,4'-ODL的热力学参数,在吸附温度范围273.15～313.15 K内,吉布斯函数变化值ΔG<0, 焓变ΔH和熵变ΔS均大于0,表明自发进行的4,4'-ODL-MIP印迹吸附4,4'-ODL是吸热和无序度增加的过程. 因此,溶液中的4,4'-ODL 被4,4'-ODL-MIP自发印迹吸附,有助于第2次电聚合反应的快速实施,以保证复合材料获得优良的吸波性能.
In order to improve the electrochemical synthesis efficiency and enhance the electromagnetic wave absorption properties of 4,4'-diaminodiphenyl ether molecularly imprinted polymer(4,4'-ODL-MIP)composite poly 4,4'-diaminodiphenyl ether(P- 4,4'-ODL)(4,4'-ODL-MIP-P- 4,4'-ODL), it is very important to investigate the mechanism of 4,4'-ODL imprinted adsorption by its MIP, which is involved to the process of the second electropolymerization of composite 4,4'-ODL-MIP-P- 4,4'-ODL. The amount of charge carried by 4,4'-ODL-MIP-P- 4,4'-ODL,closely relating to its electromagnetic wave absorption, can be conducted to be the amount of adsorption in this paper. At the temperature of 298 K, Langmuir, Brunauer-Emmett-Teller(BET), Freundlich, D-R,Temkin and Henry adsorption models were fitted by the charge of composite.The fitting data showed that the three isothermal adsorption models of Langmuir, Dubinin-Radushkevich and Henry were more suitable for simulating the imprinted adsorption of 4,4'-ODL-MIP on 4,4'-ODL in solution during the second electropolymerization. Meanwhile, the results of the four adsorption kinetic rate equations fitted by charge(quasi-first-order, quasi-second-order, Elovich and intragranular diffusion)exhibited that 4,4'-ODL-MIP adsorption 4,4'-ODL was followed the quasi-first-order, while its rate was controlled by the liquid film and intra-particle diffusion. Also, in the temperature range from 273.15 to 313.15 K, the thermaldynamic parameters estimated by charge of this imprinted adsorption showed that ΔH and ΔS were both larger than zero, while ΔG was less than zero. This indicated that the above spontaneously imprinted adsorption was an endothermic process, while its disorder increased at the same time. Therefore, this imprinted adsorption was advantage to perform the second electropolymerization fastly, to safeguard the good electromagnetic wave absorption properties of the composite.
