Cathodic shrinking

The PP film used as the anode is swollen by the entry of hydrated CIOJ counterions, while the other PP layer, which acts as the cathode, shrinks because of the expulsion of counterions and water molecules. These volume changes and the constant length of the nonconducting film promotes the movement of the triple layer towards the PP film that is contracted. Upon changing the direction of the current. 

Flory osmotic pressures at the anode and cathode sides have been calculated using Eqs. 3-10. In a system of i cations and j anions, the osmotic pressures are given by a summation of Eqs. 3-10. When dn/dt > 0 in an electric field, the gel swells. It shrinks when dn/dt < 0. When n at the anode side becomes larger than that at the cathode side, the gel bends toward the cathode. 

As the electric current passes through this system, the cathode (negative electrode) grows in thickness while the anode (positive electrode) shrinks. At the cathode, M+ ions are converted to M atoms, which results in growth of the cathode. From this observation, it is clear that the cations are primarily responsible for conductivity, and this is the result of a vacancy type of mechanism. In this case, the positive ion vacancies have higher mobility than do the vacancies that involve negative ions. 

Each sequential reaction took place at a slightly higher equilibrium oxidation potential and resulted in a shrinking of the solid lattice (densities chalcocite, 5.6 covellite, 4.6 rhombic sulfur, 2.07 g cm" ) (Weast, 1974). The cathodic reactions were ... 

In the case of NEOSEPTA-F C-2000, the current efficiency increases with increase of sodium hydroxide concentration in catholyte. It is thought that the water in the membrane surface portion of cathode side is dehydrated and the concentration of fixed ion in the membrane increases. The presumption that the cathode side of the membrane surface would shrink with the increase of sodium hydroxide concentration is obviously proved in the relationship between the sodium hydroxide concentration in catholyte and sodium chloride concentration in the product ( Figure 6 ), The diffused amount of sodium chloride decreased remarkably with increase of sodium hydroxide concentration. 

The use of rigid polycarbonate sleeves serves as an alternative. According to manufacturer specifications, these UV-absorbing sleeves reduce the majority of UV emissions from fluorescent bulbs. These rigid filters do not shrink from the cathode ends of the bulb, and they reduce the potential for bulb damage. The sleeves may last up to 10 years, with a slight yellowing of the material (32). 

It is well known that polyelectrolyte gels swell, shrink or bend when DC electric current is applied [169]. These properties of gels are applicable for the construction of chemomechanical devices, artificial muscles, energy conversion systems etc. [170]. Osada and co-workers [171] have constructed an eel-like gel actuator on the basis of poly(2-acrylamido-2-methylpropane sulfonic acid) and studied its chemomechanical properties. Polyampholyte gel is bent to the cathode or anode side if it has predominantly negative or positive charges along the macromolecules (Fig. 39) [172]. As seen from Fig. 39, the amplitude of deflection is gradually decreased with the approach to the lEP. This is probably due to... 

From their theory derivations, they concluded that for a cationic gel exposed to an electric field, if the gel comes in contact with the anode, that particular side will undergo shrinking. However, if the gel is sufficiently separated from the anode, die side of the gel near the anode will first swell and then shrink (Doi et al. 1992). As for die cathode side, shrinking of the gel occurs regardless of contact. 

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