# Electrical Property Measurement on Antistatic Coating During Aging Process
## 3 Results and Discussion
### Samples After Aging Process in Outer Environmental Conditions  
This aging process took place in outer environmental conditions during the winter months of December and January (60 days). We can consider these months as the coldest on average and they have the highest volume of precipitation in the form of snow or rain. In addition, foggy weather with low air pressure appears often in these months. The conductive currents were measured, and they were significantly higher in comparison to the samples with the aging process in the oven. This is caused by high humidity in the environment. The typical conductive current value for PANI samples on a steel plate was \(I_{G}\approx 25\) uA, with TiO\({}_{2}\)/PANI \(I_{G}\approx 12\) uA, and with other coatings, it was \(I_{G}\approx 10\) uA. In cases with a glass sheet, the current had values in the range from 2 to 10 uA, with the highest value for perovskite containing CaTiO\({}_{3}\). The capacitance was similar to the samples with oven aging; they had values between 150 and 200 pF for steel plate samples and 50 to 110 pF for the glass sheet. The TiO\({}_{2}\)/PPY coating had the highest capacitance value on steel plate and BISIL on glass. The difference between both aging processes can be observed in the loss factor parameter \(tg\)\(\delta\). This parameter was higher in comparison to the samples without aging, especially for PANI paints. This set of measurements showed that the most suitable paint type for electrostatic charge elimination is the PANI polymer or the composite TiO\({}_{2}\)/PANI. In the following graphs in Figure 6, the charging currents are depicted on non-conductive vs. conductive coatings. Figure 6(a) shows the charging current waveform of a non-conductive coating on a glass substrate. When measuring the charging current of a coating on a glass substrate (non  
Figure 6: Charging current before the aging process—glass sheet. conductive material), the surface conductivity of the coating is more apparent. The charging current initially decreases gradually, and later, the decrease is more abrupt. The charging current for this semi-conductive coating converts to a conduction current approaching 35 \(\upmu\)A. Figure 6b shows the charge current waveform for the semiconducting material. The current decreases exponentially and tends to a conduction current value of 350 \(\upmu\)A, which is ten times larger than that of the non-conductive material. In Figure 7, we can see the capacitance values for different frequencies in comparison between two situations--before the aging process and between glass and steel plates. When measuring the coating capacitance on the conductive substrate, the bulk capacitance is more apparent than the surface capacitance. When measuring it, we actually have a series-parallel connection of three capacitors. In one parallel branch is the surface capacitance of the coating, and in the other branch, there is a series connection of the two bulk capacitances (outer electrode--metal and metal--inner electrode). Therefore, the resulting coating capacitance for a metal substrate is significantly different from that for a glass substrate, where the bulk capacitance is not very evident. Figure 7: IDAX insulation diagnostic analyzer: Paint capacitance before the aging process—steel pad. Figure 8 shows the difference in loss factor values between steel and glass plates for different painting types. When measuring the loss factor, the same assumptions apply as when measuring capacity. For a glass substrate, the surface conductivity is more apparent and for a metallic item, the bulk conductivity. Figure 9 shows the capacitance of different painting types on a glass sheet. The BISIL coatings had the highest capacitance for the steel plate case. Other capacitance values for other samples were evenly distributed in the 90-170 pF range. The loss factor has a decreasing tendency in this case. In the higher frequency range, the most conductive coating was PANI in comparison with other samples.