Ion-Selective Electrode With Ion-Occluding Layer for Stable Potential
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solid-contact ion-selective electrodes suffer from low reproducibility and stability of potential, making them less reliable compared to internal liquid type electrodes.
Innovation Solution
The use of an ion occluding material that occludes the target ion as a base electrode, with controlled ion occlusion rates, is integrated into the electrode structure, utilizing materials like Prussian blue analogs containing transition metals to enhance stability and reproducibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a solid-contact ion-selective electrode is used to eliminate internal liquid, then the device volume is reduced, but the potential stability and reproducibility deteriorate
Solution Approach 1:
An ion occluding material layer is introduced as an intermediary between the internal electrode and the ion-sensitive film. This layer mediates the interaction between the solid electrode and the membrane, enabling stable potential generation without requiring internal liquid filling.
Solution Approach 2:
The electrical properties of the internal electrode are modified by coating it with an ion occluding material layer that has specific ion exchange capacity and conductivity characteristics, transforming it from a simple conductive element to an active ion-selective component.
2Device complexity
If a solid-contact ion-selective electrode is used to eliminate internal liquid, then the device complexity is reduced, but the measurement precision deteriorates
Solution Approach 1:
The internal electrode is constructed as a composite structure combining a conductive base material (such as metal or carbon) with an ion occluding material layer (such as Prussian blue or its analogs), achieving both electrical conductivity and ion-selective properties in a single component.
3Reliability
If ion occluding material is used with controlled ion occlusion rates, then the potential stability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The ion occluding material layer is pre-formed on the internal electrode with controlled ion occlusion characteristics before final electrode assembly. This preliminary preparation ensures consistent potential stability without requiring precise control during the final manufacturing process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach achieves high potential stability and reproducibility, allowing for predictable potentials and easy calibration, comparable to internal liquid type electrodes.
Implementation Method 1
an ion occluding material which occluded the target ion to be measured
Implementation Method 2
An interface potential in accordance with the Nernst equation is generated between the ion sensitive film and an aqueous solution in contact therewith
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
There is provided a solid-contact ion-selective electrode having a high potential stability and potential reproducibility. The ion-selective electrode includes an ion sensitive film 101 having a Group-1 element ion, a Group-2 element ion, a hydronium ion or an ammonium ion as a target ion, an ion occluding material layer 102, and a conductive electrode 103, wherein the ion occluding material contained in the ion occludes material layer 102 occluding the target ion, the ion occluding material being a Prussian blue analog represented by the structure formula AaMx[M'(CN)6]y□z•kH20. Herein, A is one type or a plurality of types of Group-1 elements, Group-2 elements, hydronium, or ammonium; M and M' are one type or a plurality of types of transition metals; M or M' includes at least one of nickel, cobalt, copper, silver, and cadmium; □ is a vacancy in a porous coordination polymer; x and y are greater than zero; and a, z, and k are numbers equal to or greater than zero.