Electrodes wire shape

The mechanical friction between the electrode surfaee under investigation and a suitable probe depends on the electrode potential showing a maximum at Ep-. Of various experimental setups reviewed previously [69Boc2] the most recent one is used to measure the frietion between a test eleetrode in wire shape and a cylindrical slider sitting on the wire [69Boel]. Results are interpreted in terms of the repulsion of double layers being present on the wire and the slider [69Boe2]. (Data obtained with this method are labelled F). 

The cathode is a wire-shaped electrode with relatively high electrical resistance, which emits electrons when heated electrically (6.3-V cathode heater circuit, which often is not shown). 

Dong, X. L., Z. Y. Guo, Y. F. Song et al. 2014. Flexible and wire-shaped micro-supercapacitor based on Ni(OFl)2-nanowire and ordered mesoporous carbon electrodes. Advanced Functional Materials 24 3405-3412. 

Figure 4.17 (a) Intertwined CNT-fibers (b) cross-section of (a) (c) schematic and working principle of wire-shaped DSSC fabricated from CNT-fiber photoanode and counter electrodes (reprinted with permission from [153]). 

Another hmitation to be considered is the volume that the DEP force can affec t. This factor can be controlled by the design of electrodes. As an example, consider elec trodes of cylindrical geometry. A practical example of this would be a cylinder with a wire running down the middle to provide the two electrodes. The field in such a system is proportional to 1/r. The DEP force is then Fdep VlE I =< 1/r, so that any differences in particle polarization might well be masked merely by positional differences in the force. At the outer cyhnder the DEP force may even be too small to affect the particles appreciably. The most desirable electrode shape is one in which the force is independent of position within the nonuniform field. This fisomotive electrode system is shown in Fig. 22-33. 

Titanium can be forged, bent, cut, stamped, rolled, extruded and successfully welded under argon, making possible a large variety of electrode shapes, i.e. rod, sheet, tube, wire or mesh. It is a very light yet strong material with a high resistance to abrasion. 

Shaped seal material Optically clean glass Wire electrode material Plantinum... 

If the platinum wire is to be used as an electrode it may be preferable not to flatten and shape it as in the Housekeeper method, but to use a mercury cup on the outside of the apparatus (Figure 42, III). The fine wire is fused into a constricted part of a narrow bore tube and the... 

The commercial silver-silver chloride electrode is similar to the SCE in that it is enclosed in glass, has nearly the same size and shape, and has a porous fiber tip for contact with the external solution. Internally, however, it is different. There is only one glass tube (unless it is a double-junction design—see Section 14.5.3) and a solution saturated in silver chloride and potassium chloride is inside. A silver wire coated at the end with a silver chloride paste extends into this solution from the external lead. See Figure 14.5. The half-reaction that occurs is... 

Microcylindrical electrodes are easier to constract and maintain than microdisk electrodes [37]. Mass transport to a stationary cylinder in quiescent solution is governed by axisymmetrical cylindrical diffusion. For square-wave voltammetry the shape and position of the net current response are independent of the extent of cyhn-drical diffusion [38]. The experiments were performed with the ferri-ferrocyanide couple using a small platinum wire (25 pm in diameter and 0.5 -1.0 cm in length) as the working electrode [37]. 

The disposable micro-glucose sensor consisted of thin-film electrodes positioned on a glass substrate and a small sample chamber (the iimer volume of which weis only 20 nL) was brought into contact with a silicon chip. Measmements were possible with as little as 1 pL of sample. The sensor sUncture is depicted in Fig. 3.18.E. The 10 x 20 mm silicon chip had a V-shaped groove that was 100-pm in wide, 70-pm deep and 5-mm long, in addition to two square sample inlets and five contact holes to connect lead wires to electrodes, all of which were formed by anisotropically etching the silicon. Four working electrodes that were 200 pm in width, and one counter-electrode that was 1.5-mm wide, were formed on a Pyrex substrate. The silicon chip and the Pyrex substrate were thermally bonded. 

In the sheathless interface, the electrical contact is obtained by coating with either a metal [85, 88-90] or a conductive polymer [91] the separation capillary outlet, which is shaped as sharp tip. Also employed are sheathless interfaces in which the electrical contact is established using a metal electrode or a conductive wire inserted into the outlet of the separation capillary [92], A small gap between the separation capillary and the needle of the ionization device filled by a liquid is the approach made to establish the electrical contact in the liquid junction interface [86,87], This arrangement is also realized by making porous through chemical etching the tip [93] or a small section of the wall [94] of the separation capillary at its outlet. 

---