Methacrylate-acrylate based polymers of low plasticiser content for potassium ion-selective membranes
✍ Scribed by Lee Yook Heng; Elizabeth A.H. Hall
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 874 KB
- Volume
- 324
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
Polymers prepared from of glycidyl methacrylate, methyl methacrylate and n-butyl acrylate were studied for their possible use as a valinomycin-based potassium ion-selective membrane with low or no plasticiser content. Four polymers were observed to be functional as potassium ion-selective membranes in the presence of valinomycin and lipophilic salt. All polymeric membranes gave Nemstian or near-Nemstian responses over the potassium ion concentration range of 10-5-10-' M. The potassium selectivity over sodium, log KpI values, for ail membranes were in the range -3.0 to -4.1 as measured by the mixed solution method with interfering sodium ion at 0.1 M. Interference of Na+ and other cations was also studied by the separate solution method. Terpolymers prepared from methacrylate-acrylate monomers with a high n-butyl acrylate ratio, required little or no o-NPOE as plasticiser to form functional potassium ion-selective membranes with only a slight decrease in potassium ion selectivity. The monomer n-butyl acrylate appeared to act as a built-in plasticiser to lower the glass transition temperature of the polymers and allowed potassium ion-selective behaviour to occur even in the absence of plasticiser.