PVC敏感膜离子识别作用的傅立叶变换——衰减全反射红外光谱研究

为了观察PVC敏感膜各成分在对离子识别时发生的变化,应用傅立叶变换-衰减全反射红外光谱研究了含有二苯并24冠8的PVC敏感膜对多种离子的识别作用。傅立叶变换-衰减全反射红外光谱显示,在PVC敏感膜与浓度为0.1mol/L的CdSO4、ZnSO4、Pb(NO3)2、Na2SO4、KCl、NaCl溶液分别反应后,归属于二苯并24冠8的吸收峰,峰高明显增高,其他一些吸收峰也有增高;而PVC敏感膜与浓度为0.1mol/L的Li2SO4、MgCl2分别反应后,PVC敏感膜各吸收峰无显著变化。还讨论了影响识别作用的一些因素,如反应时间、阴离子的作用、敏感膜发生识别作用的位置。结果表明:含有二苯并24冠8的PVC敏感膜对不同离子有选择识别的作用,可选择识别Cd2+、Zn2+、Pb2+、K+、Na+,不能识别Li+、Mg2,PVC敏感膜中的中性离子载体二苯并24冠8对离子的识别起主要作用,四(4—氯苯)硼钾也参与了识别作用。

Cation Selective Recognition of PVC Sensitive Membranes as Studied by Fourier Transform Infrared Attenuated Total Reflection Spectrometry

To observe what have been taken place when pvc sensitive membrane reacted with some cations in water,attenuated total reflectance Fourier transform infrared spectrometry(FTIR-ATR),have been used to study the selective recognition of pvc sensitive membrane incorporated dibenzo 24 –crown-8 when it reacted with some special ion in water.The FTIR-ATR spectrum showed the peaks responsible for dibenzo 24 –crown-8,and some other peaks,have been changed higher,after the pvc sensitive membrane reacted with 0.1 mol/L CdSO4,ZnSO4,Pb(NO3)2,Na2SO4,KCl and NaCl solution respectively.But have been not changed anymore,after the pvc sensitive membrane reacted with 0.1mol/L Li2SO4 and MgCl2 solution respectively.And some influence factors,such as reaction time,counter anion,reaction position of pvc sensitive membrane,also have been discuussed.The results indicated the pvc sensitive membrane can selective react with Cd2+,Zn2+,Pb2+,K+ and Na+,can not react with Li+,Mg2+.When the selective reaction taken place,dibenzo 24 –crown-8 on pvc sensitive membrane have been changed more,the lipophilic ionic sites reagent potassium tetrakis(4-chlorophenyl)borate changed too.