Abstract
Poly (vinyl chloride) (PVC) based membranes containing p-tert-butylcalix [6] arene (I) in the molecular form as an electroactive material along with anion excluder sodium tetraphenyl borate (NaTPB) and plasticizer Di-Octyl phthalate (DOP) have been used to fabricate a new cadmium-selective sensor. Out of the various compositions, the best performance was exhibited by the membrane having I-PVC-NaTPB-DOP in the ratio 1:33:1:65 (w/w). The sensor works well in the concentration range 9.7 x 10(-5) to 1 x 10(-1) mol dm(-3) with a near-Nernstian slope of 29.0 +/- 1 mV/decade of activity. The working pH range of this sensor is 2.8 to 6.2 and its performance was found satisfactory up to 20% non-aqueous medium. It exhibits a fast response time of 35 s and could be used for more than 4 months without any considerable change in response characteristics. It has excellent selectivity for Cd(II) over alkali, alkaline and other heavy metal cations. (C) 2014 Elsevier B.V. All rights reserved.