Glass electrodes temperature effects

FIGURE 10.2 A schematic diagram of a combination glass pH electrode. A thin glass bulb with an inner Ag/AgCI electrode responds to pH changes in the test solution. A second Ag/AgCI in an outer jacket with a liquid junction serves the reference electrode for potentiometric measurement. An attached temperature probe is used to compensate for temperature effects. 

If anodic bonding between glass and Si fails (due to a thick oxide layer [1 im] on Si or platinum electrode on Si), a low-melting spin-on-glass (SOG) can be applied as an adhesive. SOG, which is a methylsilsesquioxane polymer, flows very well at the temperature between 150°C and 210°C, and therefore it fills the grooves (i.e., around the Pt electrodes) for effective bonding [93]. 

Temperature effects. The ordinary glass electrode-reference electrode pair that is used for pH measurements is not well suited to measurements far removed from room temperature. This is because the electrodes are immersed only partially, with the tips of the electrodes in the solution and the tops of the electrodes at ambient temperature. This creates a thermal gradient in the body... 

To function as an effective polyelectrolyte, the polymer should have a low glass transition temperature to allow the freedom of molecular movement necessary for ion transport. While the advantages of PEO-alkali metal complexes are their good electrochemical stability as well as faster kinetics at the ion transfer between electrode and electrolyte, the disadvantage is the low conductivity of the polymeric electrolyte at normal operating temperatures. Thus, in order to obtain high-power densities, it is necessary to work... 

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