Ion sensors using one-component room temperature vulcanized silicone rubber matrices

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 464; no. 2; pp. 135 - 142
• Main Authors: Yoon, In Jun, Lee, Dong Kwon, Nam, Hakhyun, Cha, Geun Sig, Strong, Timothy D., Brown, Richard B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 29-03-1999; Elsevier Science
• Subjects: Carbonate sensor; Chemistry; Electrochemistry; Electrodes: preparations and properties; Exact sciences and technology; General and physical chemistry; Ion selective electrodes; Ion-selective membrane; Silicone rubber; Solid-state sensor; Ion-selective membrane; Carbonate sensor; Solid-state sensor; Silicone rubber; Ion selective electrode; Membrane electrode; Ionic selectivity; Proton; Carbonates; Ionophore; Calcium Ions; Experimental study; Potentiometry; Potassium Ions; Silicone elastomer
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/S0022-0728(99)00010-8

Two different types of one-component room temperature vulcanized (RTV) silicone rubbers (Dow Corning 3140 and 730 RTV) are further examined as alternatives to PVC for formulating ion-selective membranes. The four different ionophores used in this work are: valinomycin (K
+), ETH 1001 (Ca
2+), tridodecylamine (H
+) and trifluoroacetyl-
p-decylbenzene (CO
3
2−). Ion-selective RTV membranes are made by incorporating an ionophore along with a plasticizer and/or an ionic additive (i.e. either plasticized or non-plasticized). In most cases, potentiometric ion responses and selectivities of RTV-based membranes, when formulated properly, compare favorably to those of corresponding PVC-based membranes. In general, 730 RTV is found to be better suited for formulating plasticizer-free membranes. The preferred matrices are a plasticized 3140 RTV for Ca
2+ and a non-plasticized 730 RTV for CO
3
2−. Planar solid-state sensors fabricated with selected RTV membrane formulations are shown to function well with a stable response signal and an extended sensor lifetime.