Characterization of All Solid State Hydrogen Ion Selective Electrode Based on PVC-SR Hybrid Membranes

Ming-Hua Piao,Gerok Jeon,Jang-Hee Yoon,Yoon-Bo Shim

doi:10.3390/s30600192

Abstract

Hydrogen ion selective membranes formulated with 3140 RTV silicone rubber (SR) in PVC were studied to extend the life time of solid state ion sensors through improved membrane adhesion. All solid state hydrogen ion selective electrodes were prepared by incorporation of tridodecyl amine (TDDA) as an ionophore, potassium tetrakis[3.5-bis(p-chlorophenyl)borate (KTpClPB) as a lipophilic additive, bis(2-ethylhexyl)adipate (DOA) as a plasticizer. Their linear dynamic range was pH 2.0-11.0 and showed the near Nernstian slope of 55.1±0.2 mV/pH (r=0.999). The ifluences from alkali and alkaline earth metal ions were studied for the response of the final ISE membrane composition. Impedance spectroscopic data showed that the resistance was increased by increasing SR content in PVC. Brewster Angle Microscopy (BAM) image showed clear differences according to the SR compositions in PVC. Life time of the all solid state membrane electrode was extended to about 2 months by preparing the membrane with PVC and SR. The standard reference material from NIST (2181 HEPES Free acid and 2182 NaHEPESate) was tested for the ISE and it gave good result.

Highlights

In views of ease of preparation, low electrical resistance, and handling safety, there have been considerable interest in non glass systems for clinical pH applications [1,2]
Potentiometric responses of hydrogen ion selective electrodes (ISEs) based on poly(vinyl chloride) (PVC)-silicone rubber (SR) matrix were examined at the first stage. 50 mol % of KTpClPB to tridodecyl amine (TDDA) was used in subsequent experiments as described in the experimental, because, there were many reports that monovalent ion using 50 mol %
The electrode of no.1 based on PVC showed near-Nernstian slope of 52.2±0.2 mV/pH (r=0.997) in pH 2.011.0 may be due to weak adhesion

Summary

Introduction

In views of ease of preparation, low electrical resistance, and handling safety, there have been considerable interest in non glass systems for clinical pH applications [1,2]. To optimize the hydrogen ion selective electrode using this composite membrane, response, selectivity coefficient, life time and reproducibility, morphologys, and membrane resistance are investigated in various SR composition in PVC.

Results

Conclusion