The relaxation of electric field-induced polar orientation in novel side and main chain polymers was measured by simultaneous second harmonic generation and thermally stimulated discharge current techniques. Using this combination of experiments, individual microscopic relaxation mechanisms could be discriminated and identified. The relaxation of a polymer bearing polar chromophores on a side chain polymer was found to occur through local reorientation. For polymers containing the polar chromophore within the main chain, both a local rotation of the chromophores and the reorientation of the end-to-end vectors of the chains could be detected. Physical aging near the Tg of the polymers greatly increased the stability of the poling-induced orientation below Tg. Nonlinear dependencies on the poling field were observed for low fields and are discussed in terms of screening due to space charges. Kirkwood–Frohlich correlation factors were found to be very close to unity.

Poling, which involves the alignment of nonlinear optical (NLO) dipolar molecules in the direction of the applied electric field, was carried out using constant current charging, a recently developed corona charging technique. Using this technique, the sample surface voltage buildup, and hence the efficiency of the dipole alignment, can be monitored during the poling process. In addition, it will be shown that this capability also provides a way to detect the end point of the dipolar orientation. Corona charging of the organic NLO film used in this study, however, needs to be done in an inert atmosphere. Results from in situ IR spectroscopy measurement during corona charging of the NLO film, ultraviolet and visible absorption spectroscopy and electron scattering for chemical analysis of this film before and after poling, indicated that exposing it to corona discharge in air ambient caused oxidation of the polymer surface. Various types of nitrogen oxides and carboxylic acids were found to be the products of this oxidation reaction. Finally, we also obtained evidence showing that the surface charging process of the organic NLO film is affected by this newly grown oxidized layer.

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Square‐wave stripping voltammetry at a carbon paste electrode was used to develop a method to measure silver ions at concentrations as low as 0.2 μg/L in surface waters. Sample matrix was found to be an important factor affecting the measurement results. Because of these matrix effects, the peak shape of the voltammograms varied, and multiple stripping peaks for silver were observed. Total charge provided a more reliable measure of deposited silver than did peak height. The precision of the method for the analysis of standard reference materials containing silver was estimated to be 7.2% relative SD at 1 SD using a 95% confidence interval of the individuals. A full factorial experiment was performed to determine how the following factors affected measurement variability: electrode, renewal of the carbon paste electrode surface, silver ion concentration, preparation of standards and samples, and day‐to‐day variability. Samples of lake and river water were collected and analyzed for silver ion. In all samples the measured concentration of silver ion was <0.2 μg/L, whereas the concentration of total silver was typically >0.5 μg/L. Spiking experiments showed that the constituents of the river water samples had a greater ability to bind (remove) silver ion than did the lake water.