Temperature effects composite plating

Coordination compounds found their application in various areas including plating, which did not lose its importance until now. Much interest in the recent investigations was shown in the problems of an applied nature, underlining the effect of plating parameters such as current density, deposition time, temperature, and pH in relation to the phase composition, structure, and quality of deposit. 

Strictly speaking, one should distinguish between the theoretical and the effective plate number. The theoretical plate number is the number of plates of an inert component (see below) and therefore a characteristic and constant value for a column under defined conditions. The effective plate number is the number of plates of a specified retained component, and the retention factor (see below) enters into the calculation. Today, however, this distinction is not made everytime one speaks only about plate number. In the most cases, the theoretical plate number is calculated, but of retained substances. In this context, it should be made clear that the plate number depends on a lot of factors, e.g. the injection volume, the temperature, the composition of the eluent, the flow rate, the retention time, the analyte, and last but not least the equation used for the calculation, i.e. peak width at the peak base, at 10% or at 50% peak height. Therefore, the comparison of literature values of plate numbers is inherently difficult. 

Non-carbon plates have also been tried. There are reports of using steel plates coated with conducting carbide materials but unfortunately are not cost effective and are quite heavy as well. In this connection it is safe to say that the polymer-carbon composite plates are cost effective if they are not considered for high capacity. Additionally, if the temperature of the PAFC is kept around 150°C, the life of these plates increases significantly. In view of this, it may be mentioned that the cost implication of the bipolar plates is very important for commercial success of PAFC based power plants. 

Changes observed in the composition of the rubber/brass interphase correlated well with results of adhesion tests carried out on brass-plated steel wires embedded in blocks of rubber [46]. The force required to pull the wires out of the blocks decreased steadily as vulcanization temperature increased. This effect was especially pronounced when the specimens were aged at elevated temperature and humidity for several days before the wires were pulled out of the rubber blocks. 

Winter et al. [119, 120] studied phase changes in the system PS/PVME under planar extensional as well as shear flow. They developed a lubrieated stagnation flow by the impingement of two rectangular jets in a specially built die having hyperbolic walls. Change of the turbidity of the blend was monitored at constant temperature. It has been found that flow-induced miscibility occurred after a duration of the order of seconds or minutes [119]. Miscibility was observed not only in planar extensional flow, but also near the die walls where the blend was subjected to shear flow. Moreover, the period of time required to induce miscibility was found to decrease with increasing flow rate. The LCST of PS/PVME was elevated in extensional flow as much as 12 K [120]. The shift depends on the extension rate, the strain and the blend composition. Flow-induced miscibility has been also found under shear flow between parallel plates when the samples were sheared near the equilibrium coexistence temperature. However, the effect of shear on polymer miscibility turned out to be less dramatic than the effect of extensional flow. The cloud point increased by 6 K at a shear rate of 2.9 s. ... 

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